examples/debugging/asyncio_bp.py

@@ -1,8 +1,16 @@
+'''
+Examples of using the builtin `breakpoint()` from an `asyncio.Task`
+running in a subactor spawned with `infect_asyncio=True`.
+
+'''
 import asyncio
 
 import trio
 import tractor
-from tractor import to_asyncio
+from tractor import (
+    to_asyncio,
+    Portal,
+)
 
 
 async def aio_sleep_forever():
@@ -23,15 +31,16 @@ async def bp_then_error(
     # NOTE: what happens here inside the hook needs some refinement..
     # => seems like it's still `._debug._set_trace()` but
     #    we set `Lock.local_task_in_debug = 'sync'`, we probably want
-    #    some further, at least, meta-data about the task/actoq in debug
-    #    in terms of making it clear it's asyncio mucking about.
+    #    some further, at least, meta-data about the task/actor in debug
+    #    in terms of making it clear it's `asyncio` mucking about.
     breakpoint()
 
+
     # short checkpoint / delay
-    await asyncio.sleep(0.5)
+    await asyncio.sleep(0.5)  # asyncio-side
 
     if raise_after_bp:
-        raise ValueError('blah')
+        raise ValueError('asyncio side error!')
 
     # TODO: test case with this so that it gets cancelled?
     else:
@@ -52,20 +61,19 @@ async def trio_ctx(
 
         to_asyncio.open_channel_from(
             bp_then_error,
-            raise_after_bp=not bp_before_started,
+            # raise_after_bp=not bp_before_started,
         ) as (first, chan),
 
-        trio.open_nursery() as n,
+        trio.open_nursery() as tn,
     ):
-
         assert first == 'start'
 
         if bp_before_started:
-            await tractor.breakpoint()
+            await tractor.pause()
 
-        await ctx.started(first)
+        await ctx.started(first)  # trio-side
 
-        n.start_soon(
+        tn.start_soon(
             to_asyncio.run_task,
             aio_sleep_forever,
         )
@@ -73,39 +81,50 @@ async def trio_ctx(
 
 
 async def main(
-    bps_all_over: bool = False,
+    bps_all_over: bool = True,
+
+    # TODO, WHICH OF THESE HAZ BUGZ?
+    cancel_from_root: bool = False,
+    err_from_root: bool = False,
 
 ) -> None:
 
     async with tractor.open_nursery(
-        # debug_mode=True,
-    ) as n:
-
-        p = await n.start_actor(
+        debug_mode=True,
+        maybe_enable_greenback=True,
+        # loglevel='devx',
+    ) as an:
+        ptl: Portal = await an.start_actor(
             'aio_daemon',
             enable_modules=[__name__],
             infect_asyncio=True,
             debug_mode=True,
-            loglevel='cancel',
+            # loglevel='cancel',
         )
 
-        async with p.open_context(
+        async with ptl.open_context(
             trio_ctx,
             bp_before_started=bps_all_over,
         ) as (ctx, first):
 
             assert first == 'start'
 
-            if bps_all_over:
-                await tractor.breakpoint()
+            # pause in parent to ensure no cross-actor
+            # locking problems exist!
+            await tractor.pause()
 
-            # await trio.sleep_forever()
+            if cancel_from_root:
                 await ctx.cancel()
+
+            if err_from_root:
                 assert 0
+            else:
+                await trio.sleep_forever()
+
 
         # TODO: case where we cancel from trio-side while asyncio task
         # has debugger lock?
-        # await p.cancel_actor()
+        # await ptl.cancel_actor()
 
 
 if __name__ == '__main__':

examples/debugging/fast_error_in_root_after_spawn.py

@@ -1,5 +1,5 @@
 '''
-Fast fail test with a context.
+Fast fail test with a `Context`.
 
 Ensure the partially initialized sub-actor process
 doesn't cause a hang on error/cancel of the parent

examples/debugging/multi_daemon_subactors.py

@@ -7,7 +7,7 @@ async def breakpoint_forever():
     try:
         while True:
             yield 'yo'
-            await tractor.breakpoint()
+            await tractor.pause()
     except BaseException:
         tractor.log.get_console_log().exception(
             'Cancelled while trying to enter pause point!'
@@ -25,7 +25,8 @@ async def main():
     """
     async with tractor.open_nursery(
         debug_mode=True,
-        loglevel='cancel',
+        # loglevel='cancel',
+        # loglevel='devx',
     ) as n:
 
         p0 = await n.start_actor('bp_forever', enable_modules=[__name__])

examples/debugging/multi_nested_subactors_error_up_through_nurseries.py

@@ -10,7 +10,7 @@ async def name_error():
 async def breakpoint_forever():
     "Indefinitely re-enter debugger in child actor."
     while True:
-        await tractor.breakpoint()
+        await tractor.pause()
 
         # NOTE: if the test never sent 'q'/'quit' commands
         # on the pdb repl, without this checkpoint line the

examples/debugging/multi_subactors.py

@@ -6,7 +6,7 @@ async def breakpoint_forever():
     "Indefinitely re-enter debugger in child actor."
     while True:
         await trio.sleep(0.1)
-        await tractor.breakpoint()
+        await tractor.pause()
 
 
 async def name_error():

examples/debugging/restore_builtin_breakpoint.py

@@ -6,19 +6,46 @@ import tractor
 
 
 async def main() -> None:
-    async with tractor.open_nursery(debug_mode=True) as an:
 
-        assert os.environ['PYTHONBREAKPOINT'] == 'tractor._debug._set_trace'
+    # intially unset, no entry.
+    orig_pybp_var: int = os.environ.get('PYTHONBREAKPOINT')
+    assert orig_pybp_var in {None, "0"}
+
+    async with tractor.open_nursery(
+        debug_mode=True,
+    ) as an:
+        assert an
+        assert (
+            (pybp_var := os.environ['PYTHONBREAKPOINT'])
+            ==
+            'tractor.devx._debug._sync_pause_from_builtin'
+        )
 
         # TODO: an assert that verifies the hook has indeed been, hooked
         # XD
-        assert sys.breakpointhook is not tractor._debug._set_trace
+        assert (
+            (pybp_hook := sys.breakpointhook)
+            is not tractor.devx._debug._set_trace
+        )
 
+        print(
+            f'$PYTHONOBREAKPOINT: {pybp_var!r}\n'
+            f'`sys.breakpointhook`: {pybp_hook!r}\n'
+        )
         breakpoint()
+        pass  # first bp, tractor hook set.
 
-    # TODO: an assert that verifies the hook is unhooked..
+    # XXX AFTER EXIT (of actor-runtime) verify the hook is unset..
+    #
+    # YES, this is weird but it's how stdlib docs say to do it..
+    # https://docs.python.org/3/library/sys.html#sys.breakpointhook
+    assert os.environ.get('PYTHONBREAKPOINT') is orig_pybp_var
     assert sys.breakpointhook
+
+    # now ensure a regular builtin pause still works
     breakpoint()
+    pass  # last bp, stdlib hook restored
+
 
 if __name__ == '__main__':
     trio.run(main)

examples/debugging/root_actor_breakpoint.py

@@ -10,7 +10,7 @@ async def main():
 
         await trio.sleep(0.1)
 
-        await tractor.breakpoint()
+        await tractor.pause()
 
         await trio.sleep(0.1)
 

examples/debugging/root_actor_breakpoint_forever.py

@@ -11,7 +11,7 @@ async def main(
         # loglevel='runtime',
     ):
         while True:
-            await tractor.breakpoint()
+            await tractor.pause()
 
 
 if __name__ == '__main__':

examples/debugging/shield_hang_in_sub.py

@@ -0,0 +1,81 @@
+'''
+Verify we can dump a `stackscope` tree on a hang.
+
+'''
+import os
+import signal
+
+import trio
+import tractor
+
+@tractor.context
+async def start_n_shield_hang(
+    ctx: tractor.Context,
+):
+    # actor: tractor.Actor = tractor.current_actor()
+
+    # sync to parent-side task
+    await ctx.started(os.getpid())
+
+    print('Entering shield sleep..')
+    with trio.CancelScope(shield=True):
+        await trio.sleep_forever()  # in subactor
+
+    # XXX NOTE ^^^ since this shields, we expect
+    # the zombie reaper (aka T800) to engage on
+    # SIGINT from the user and eventually hard-kill
+    # this subprocess!
+
+
+async def main(
+    from_test: bool = False,
+) -> None:
+
+    async with (
+        tractor.open_nursery(
+            debug_mode=True,
+            enable_stack_on_sig=True,
+            # maybe_enable_greenback=False,
+            loglevel='devx',
+        ) as an,
+    ):
+
+        ptl: tractor.Portal  = await an.start_actor(
+            'hanger',
+            enable_modules=[__name__],
+            debug_mode=True,
+        )
+        async with ptl.open_context(
+            start_n_shield_hang,
+        ) as (ctx, cpid):
+
+            _, proc, _ = an._children[ptl.chan.uid]
+            assert cpid == proc.pid
+
+            print(
+                'Yo my child hanging..?\n'
+                'Sending SIGUSR1 to see a tree-trace!\n'
+            )
+
+            # XXX simulate the wrapping test's "user actions"
+            # (i.e. if a human didn't run this manually but wants to
+            # know what they should do to reproduce test behaviour)
+            if from_test:
+                os.kill(
+                    cpid,
+                    signal.SIGUSR1,
+                )
+
+                # simulate user cancelling program
+                await trio.sleep(0.5)
+                os.kill(
+                    os.getpid(),
+                    signal.SIGINT,
+                )
+            else:
+                # actually let user send the ctl-c
+                await trio.sleep_forever()  # in root
+
+
+if __name__ == '__main__':
+    trio.run(main)

examples/debugging/subactor_bp_in_ctx.py

@@ -4,9 +4,9 @@ import trio
 
 async def gen():
     yield 'yo'
-    await tractor.breakpoint()
+    await tractor.pause()
     yield 'yo'
-    await tractor.breakpoint()
+    await tractor.pause()
 
 
 @tractor.context
@@ -15,7 +15,7 @@ async def just_bp(
 ) -> None:
 
     await ctx.started()
-    await tractor.breakpoint()
+    await tractor.pause()
 
     # TODO: bps and errors in this call..
     async for val in gen():

examples/debugging/sync_bp.py

@@ -4,6 +4,13 @@ import time
 import trio
 import tractor
 
+# TODO: only import these when not running from test harness?
+# can we detect `pexpect` usage maybe?
+# from tractor.devx._debug import (
+#     get_lock,
+#     get_debug_req,
+# )
+
 
 def sync_pause(
     use_builtin: bool = False,
@@ -18,7 +25,13 @@ def sync_pause(
         breakpoint(hide_tb=hide_tb)
 
     else:
+        # TODO: maybe for testing some kind of cm style interface
+        # where the `._set_trace()` call doesn't happen until block
+        # exit?
+        # assert get_lock().ctx_in_debug is None
+        # assert get_debug_req().repl is None
         tractor.pause_from_sync()
+        # assert get_debug_req().repl is None
 
     if error:
         raise RuntimeError('yoyo sync code error')
@@ -41,10 +54,11 @@ async def start_n_sync_pause(
 async def main() -> None:
     async with (
         tractor.open_nursery(
-            # NOTE: required for pausing from sync funcs
-            maybe_enable_greenback=True,
             debug_mode=True,
-            # loglevel='cancel',
+            maybe_enable_greenback=True,
+            enable_stack_on_sig=True,
+            # loglevel='warning',
+            # loglevel='devx',
         ) as an,
         trio.open_nursery() as tn,
     ):
@@ -138,7 +152,9 @@ async def main() -> None:
                     # the case 2. from above still exists!
                     use_builtin=True,
                 ),
-                abandon_on_cancel=False,
+                # TODO: with this `False` we can hang!??!
+                # abandon_on_cancel=False,
+                abandon_on_cancel=True,
                 thread_name='inline_root_bg_thread',
             )
 

examples/service_discovery.py

@@ -9,7 +9,7 @@ async def main(service_name):
     async with tractor.open_nursery() as an:
         await an.start_actor(service_name)
 
-        async with tractor.get_arbiter('127.0.0.1', 1616) as portal:
+        async with tractor.get_registry('127.0.0.1', 1616) as portal:
             print(f"Arbiter is listening on {portal.channel}")
 
         async with tractor.wait_for_actor(service_name) as sockaddr:

notes_to_self/howtorelease.md

@@ -0,0 +1,18 @@
+First generate a built disti:
+
+```
+python -m pip install --upgrade build 
+python -m build --sdist --outdir dist/alpha5/
+```
+
+Then try a test ``pypi`` upload:
+
+```
+python -m twine upload --repository testpypi dist/alpha5/*
+```
+
+The push to `pypi` for realz.
+
+```
+python -m twine upload --repository testpypi dist/alpha5/*
+```

tests/devx/conftest.py

@@ -0,0 +1,219 @@
+'''
+`tractor.devx.*` tooling sub-pkg test space.
+
+'''
+import time
+from typing import (
+    Callable,
+)
+
+import pytest
+from pexpect.exceptions import (
+    TIMEOUT,
+)
+from pexpect.spawnbase import SpawnBase
+
+from tractor._testing import (
+    mk_cmd,
+)
+from tractor.devx._debug import (
+    _pause_msg as _pause_msg,
+    _crash_msg as _crash_msg,
+    _repl_fail_msg as _repl_fail_msg,
+    _ctlc_ignore_header as _ctlc_ignore_header,
+)
+from conftest import (
+    _ci_env,
+)
+
+
+@pytest.fixture
+def spawn(
+    start_method,
+    testdir: pytest.Testdir,
+    reg_addr: tuple[str, int],
+
+) -> Callable[[str], None]:
+    '''
+    Use the `pexpect` module shipped via `testdir.spawn()` to
+    run an `./examples/..` script by name.
+
+    '''
+    if start_method != 'trio':
+        pytest.skip(
+            '`pexpect` based tests only supported on `trio` backend'
+        )
+
+    def _spawn(
+        cmd: str,
+        **mkcmd_kwargs,
+    ):
+        return testdir.spawn(
+            cmd=mk_cmd(
+                cmd,
+                **mkcmd_kwargs,
+            ),
+            expect_timeout=3,
+        )
+
+    # such that test-dep can pass input script name.
+    return _spawn
+
+
+@pytest.fixture(
+    params=[False, True],
+    ids='ctl-c={}'.format,
+)
+def ctlc(
+    request,
+    ci_env: bool,
+
+) -> bool:
+
+    use_ctlc = request.param
+
+    node = request.node
+    markers = node.own_markers
+    for mark in markers:
+        if mark.name == 'has_nested_actors':
+            pytest.skip(
+                f'Test {node} has nested actors and fails with Ctrl-C.\n'
+                f'The test can sometimes run fine locally but until'
+                ' we solve' 'this issue this CI test will be xfail:\n'
+                'https://github.com/goodboy/tractor/issues/320'
+            )
+
+    if use_ctlc:
+        # XXX: disable pygments highlighting for auto-tests
+        # since some envs (like actions CI) will struggle
+        # the the added color-char encoding..
+        from tractor.devx._debug import TractorConfig
+        TractorConfig.use_pygements = False
+
+    yield use_ctlc
+
+
+def expect(
+    child,
+
+    # normally a `pdb` prompt by default
+    patt: str,
+
+    **kwargs,
+
+) -> None:
+    '''
+    Expect wrapper that prints last seen console
+    data before failing.
+
+    '''
+    try:
+        child.expect(
+            patt,
+            **kwargs,
+        )
+    except TIMEOUT:
+        before = str(child.before.decode())
+        print(before)
+        raise
+
+
+PROMPT = r"\(Pdb\+\)"
+
+
+def in_prompt_msg(
+    child: SpawnBase,
+    parts: list[str],
+
+    pause_on_false: bool = False,
+    err_on_false: bool = False,
+    print_prompt_on_false: bool = True,
+
+) -> bool:
+    '''
+    Predicate check if (the prompt's) std-streams output has all
+    `str`-parts in it.
+
+    Can be used in test asserts for bulk matching expected
+    log/REPL output for a given `pdb` interact point.
+
+    '''
+    __tracebackhide__: bool = False
+
+    before: str = str(child.before.decode())
+    for part in parts:
+        if part not in before:
+            if pause_on_false:
+                import pdbp
+                pdbp.set_trace()
+
+            if print_prompt_on_false:
+                print(before)
+
+            if err_on_false:
+                raise ValueError(
+                    f'Could not find pattern in `before` output?\n'
+                    f'part: {part!r}\n'
+                )
+            return False
+
+    return True
+
+
+# TODO: todo support terminal color-chars stripping so we can match
+# against call stack frame output from the the 'll' command the like!
+# -[ ] SO answer for stipping ANSI codes: https://stackoverflow.com/a/14693789
+def assert_before(
+    child: SpawnBase,
+    patts: list[str],
+
+    **kwargs,
+
+) -> None:
+    __tracebackhide__: bool = False
+
+    assert in_prompt_msg(
+        child=child,
+        parts=patts,
+
+        # since this is an "assert" helper ;)
+        err_on_false=True,
+        **kwargs
+    )
+
+
+def do_ctlc(
+    child,
+    count: int = 3,
+    delay: float = 0.1,
+    patt: str|None = None,
+
+    # expect repl UX to reprint the prompt after every
+    # ctrl-c send.
+    # XXX: no idea but, in CI this never seems to work even on 3.10 so
+    # needs some further investigation potentially...
+    expect_prompt: bool = not _ci_env,
+
+) -> str|None:
+
+    before: str|None = None
+
+    # make sure ctl-c sends don't do anything but repeat output
+    for _ in range(count):
+        time.sleep(delay)
+        child.sendcontrol('c')
+
+        # TODO: figure out why this makes CI fail..
+        # if you run this test manually it works just fine..
+        if expect_prompt:
+            time.sleep(delay)
+            child.expect(PROMPT)
+            before = str(child.before.decode())
+            time.sleep(delay)
+
+            if patt:
+                # should see the last line on console
+                assert patt in before
+
+    # return the console content up to the final prompt
+    return before

tests/devx/test_debugger.py

@@ -13,26 +13,25 @@ TODO:
 from functools import partial
 import itertools
 import platform
-import pathlib
 import time
 
 import pytest
-import pexpect
 from pexpect.exceptions import (
     TIMEOUT,
     EOF,
 )
 
-from tractor.devx._debug import (
+from .conftest import (
+    do_ctlc,
+    PROMPT,
     _pause_msg,
     _crash_msg,
     _repl_fail_msg,
 )
-from tractor._testing import (
-    examples_dir,
-)
-from conftest import (
-    _ci_env,
+from .conftest import (
+    expect,
+    in_prompt_msg,
+    assert_before,
 )
 
 # TODO: The next great debugger audit could be done by you!
@@ -52,15 +51,6 @@ if platform.system() == 'Windows':
     )
 
 
-def mk_cmd(ex_name: str) -> str:
-    '''
-    Generate a command suitable to pass to ``pexpect.spawn()``.
-
-    '''
-    script_path: pathlib.Path = examples_dir() / 'debugging' / f'{ex_name}.py'
-    return ' '.join(['python', str(script_path)])
-
-
 # TODO: was trying to this xfail style but some weird bug i see in CI
 # that's happening at collect time.. pretty soon gonna dump actions i'm
 # thinkin...
@@ -79,142 +69,6 @@ has_nested_actors = pytest.mark.has_nested_actors
 # )
 
 
-@pytest.fixture
-def spawn(
-    start_method,
-    testdir,
-    reg_addr,
-) -> 'pexpect.spawn':
-
-    if start_method != 'trio':
-        pytest.skip(
-            "Debugger tests are only supported on the trio backend"
-        )
-
-    def _spawn(cmd):
-        return testdir.spawn(
-            cmd=mk_cmd(cmd),
-            expect_timeout=3,
-        )
-
-    return _spawn
-
-
-PROMPT = r"\(Pdb\+\)"
-
-
-def expect(
-    child,
-
-    # prompt by default
-    patt: str = PROMPT,
-
-    **kwargs,
-
-) -> None:
-    '''
-    Expect wrapper that prints last seen console
-    data before failing.
-
-    '''
-    try:
-        child.expect(
-            patt,
-            **kwargs,
-        )
-    except TIMEOUT:
-        before = str(child.before.decode())
-        print(before)
-        raise
-
-
-def in_prompt_msg(
-    prompt: str,
-    parts: list[str],
-
-    pause_on_false: bool = False,
-    print_prompt_on_false: bool = True,
-
-) -> bool:
-    '''
-    Predicate check if (the prompt's) std-streams output has all
-    `str`-parts in it.
-
-    Can be used in test asserts for bulk matching expected
-    log/REPL output for a given `pdb` interact point.
-
-    '''
-    __tracebackhide__: bool = False
-
-    for part in parts:
-        if part not in prompt:
-            if pause_on_false:
-                import pdbp
-                pdbp.set_trace()
-
-            if print_prompt_on_false:
-                print(prompt)
-
-            return False
-
-    return True
-
-
-# TODO: todo support terminal color-chars stripping so we can match
-# against call stack frame output from the the 'll' command the like!
-# -[ ] SO answer for stipping ANSI codes: https://stackoverflow.com/a/14693789
-def assert_before(
-    child,
-    patts: list[str],
-
-    **kwargs,
-
-) -> None:
-    __tracebackhide__: bool = False
-
-    # as in before the prompt end
-    before: str = str(child.before.decode())
-    assert in_prompt_msg(
-        prompt=before,
-        parts=patts,
-
-        **kwargs
-    )
-
-
-@pytest.fixture(
-    params=[False, True],
-    ids='ctl-c={}'.format,
-)
-def ctlc(
-    request,
-    ci_env: bool,
-
-) -> bool:
-
-    use_ctlc = request.param
-
-    node = request.node
-    markers = node.own_markers
-    for mark in markers:
-        if mark.name == 'has_nested_actors':
-            pytest.skip(
-                f'Test {node} has nested actors and fails with Ctrl-C.\n'
-                f'The test can sometimes run fine locally but until'
-                ' we solve' 'this issue this CI test will be xfail:\n'
-                'https://github.com/goodboy/tractor/issues/320'
-            )
-
-    if use_ctlc:
-        # XXX: disable pygments highlighting for auto-tests
-        # since some envs (like actions CI) will struggle
-        # the the added color-char encoding..
-        from tractor.devx._debug import TractorConfig
-        TractorConfig.use_pygements = False
-
-    yield use_ctlc
-
-
 @pytest.mark.parametrize(
     'user_in_out',
     [
@@ -238,14 +92,15 @@ def test_root_actor_error(
     # scan for the prompt
     expect(child, PROMPT)
 
-    before = str(child.before.decode())
-
     # make sure expected logging and error arrives
     assert in_prompt_msg(
-        before,
-        [_crash_msg, "('root'"]
+        child,
+        [
+            _crash_msg,
+            "('root'",
+            'AssertionError',
+        ]
     )
-    assert 'AssertionError' in before
 
     # send user command
     child.sendline(user_input)
@@ -264,8 +119,10 @@ def test_root_actor_error(
     ids=lambda item: f'{item[0]} -> {item[1]}',
 )
 def test_root_actor_bp(spawn, user_in_out):
-    """Demonstrate breakpoint from in root actor.
-    """
+    '''
+    Demonstrate breakpoint from in root actor.
+
+    '''
     user_input, expect_err_str = user_in_out
     child = spawn('root_actor_breakpoint')
 
@@ -279,7 +136,7 @@ def test_root_actor_bp(spawn, user_in_out):
     child.expect('\r\n')
 
     # process should exit
-    child.expect(pexpect.EOF)
+    child.expect(EOF)
 
     if expect_err_str is None:
         assert 'Error' not in str(child.before)
@@ -287,38 +144,6 @@ def test_root_actor_bp(spawn, user_in_out):
         assert expect_err_str in str(child.before)
 
 
-def do_ctlc(
-    child,
-    count: int = 3,
-    delay: float = 0.1,
-    patt: str|None = None,
-
-    # expect repl UX to reprint the prompt after every
-    # ctrl-c send.
-    # XXX: no idea but, in CI this never seems to work even on 3.10 so
-    # needs some further investigation potentially...
-    expect_prompt: bool = not _ci_env,
-
-) -> None:
-
-    # make sure ctl-c sends don't do anything but repeat output
-    for _ in range(count):
-        time.sleep(delay)
-        child.sendcontrol('c')
-
-        # TODO: figure out why this makes CI fail..
-        # if you run this test manually it works just fine..
-        if expect_prompt:
-            before = str(child.before.decode())
-            time.sleep(delay)
-            child.expect(PROMPT)
-            time.sleep(delay)
-
-            if patt:
-                # should see the last line on console
-                assert patt in before
-
-
 def test_root_actor_bp_forever(
     spawn,
     ctlc: bool,
@@ -358,7 +183,7 @@ def test_root_actor_bp_forever(
 
     # quit out of the loop
     child.sendline('q')
-    child.expect(pexpect.EOF)
+    child.expect(EOF)
 
 
 @pytest.mark.parametrize(
@@ -380,10 +205,12 @@ def test_subactor_error(
     # scan for the prompt
     child.expect(PROMPT)
 
-    before = str(child.before.decode())
     assert in_prompt_msg(
-        before,
-        [_crash_msg, "('name_error'"]
+        child,
+        [
+            _crash_msg,
+            "('name_error'",
+        ]
     )
 
     if do_next:
@@ -402,17 +229,15 @@ def test_subactor_error(
         child.sendline('continue')
 
     child.expect(PROMPT)
-    before = str(child.before.decode())
-
+    assert in_prompt_msg(
+        child,
+        [
+            _crash_msg,
             # root actor gets debugger engaged
-    assert in_prompt_msg(
-        before,
-        [_crash_msg, "('root'"]
-    )
+            "('root'",
             # error is a remote error propagated from the subactor
-    assert in_prompt_msg(
-        before,
-        [_crash_msg, "('name_error'"]
+            "('name_error'",
+        ]
     )
 
     # another round
@@ -423,7 +248,7 @@ def test_subactor_error(
     child.expect('\r\n')
 
     # process should exit
-    child.expect(pexpect.EOF)
+    child.expect(EOF)
 
 
 def test_subactor_breakpoint(
@@ -433,14 +258,11 @@ def test_subactor_breakpoint(
     "Single subactor with an infinite breakpoint loop"
 
     child = spawn('subactor_breakpoint')
-
-    # scan for the prompt
     child.expect(PROMPT)
-
-    before = str(child.before.decode())
     assert in_prompt_msg(
-        before,
-        [_pause_msg, "('breakpoint_forever'"]
+        child,
+        [_pause_msg,
+         "('breakpoint_forever'",]
     )
 
     # do some "next" commands to demonstrate recurrent breakpoint
@@ -456,9 +278,8 @@ def test_subactor_breakpoint(
     for _ in range(5):
         child.sendline('continue')
         child.expect(PROMPT)
-        before = str(child.before.decode())
         assert in_prompt_msg(
-            before,
+            child,
             [_pause_msg, "('breakpoint_forever'"]
         )
 
@@ -471,9 +292,8 @@ def test_subactor_breakpoint(
     # child process should exit but parent will capture pdb.BdbQuit
     child.expect(PROMPT)
 
-    before = str(child.before.decode())
     assert in_prompt_msg(
-        before,
+        child,
         ['RemoteActorError:',
          "('breakpoint_forever'",
          'bdb.BdbQuit',]
@@ -486,11 +306,10 @@ def test_subactor_breakpoint(
     child.sendline('c')
 
     # process should exit
-    child.expect(pexpect.EOF)
+    child.expect(EOF)
 
-    before = str(child.before.decode())
     assert in_prompt_msg(
-        before,
+        child,
         ['RemoteActorError:',
          "('breakpoint_forever'",
          'bdb.BdbQuit',]
@@ -514,7 +333,7 @@ def test_multi_subactors(
 
     before = str(child.before.decode())
     assert in_prompt_msg(
-        before,
+        child,
         [_pause_msg, "('breakpoint_forever'"]
     )
 
@@ -535,12 +354,14 @@ def test_multi_subactors(
 
     # first name_error failure
     child.expect(PROMPT)
-    before = str(child.before.decode())
     assert in_prompt_msg(
-        before,
-        [_crash_msg, "('name_error'"]
+        child,
+        [
+            _crash_msg,
+            "('name_error'",
+            "NameError",
+        ]
     )
-    assert "NameError" in before
 
     if ctlc:
         do_ctlc(child)
@@ -564,9 +385,8 @@ def test_multi_subactors(
     # breakpoint loop should re-engage
     child.sendline('c')
     child.expect(PROMPT)
-    before = str(child.before.decode())
     assert in_prompt_msg(
-        before,
+        child,
         [_pause_msg, "('breakpoint_forever'"]
     )
 
@@ -629,7 +449,7 @@ def test_multi_subactors(
 
     # process should exit
     child.sendline('c')
-    child.expect(pexpect.EOF)
+    child.expect(EOF)
 
     # repeat of previous multierror for final output
     assert_before(child, [
@@ -659,25 +479,28 @@ def test_multi_daemon_subactors(
     # the root's tty lock first so anticipate either crash
     # message on the first entry.
 
-    bp_forev_parts = [_pause_msg, "('bp_forever'"]
+    bp_forev_parts = [
+        _pause_msg,
+        "('bp_forever'",
+    ]
     bp_forev_in_msg = partial(
         in_prompt_msg,
         parts=bp_forev_parts,
     )
 
-    name_error_msg = "NameError: name 'doggypants' is not defined"
-    name_error_parts = [name_error_msg]
+    name_error_msg: str = "NameError: name 'doggypants' is not defined"
+    name_error_parts: list[str] = [name_error_msg]
 
     before = str(child.before.decode())
 
-    if bp_forev_in_msg(prompt=before):
+    if bp_forev_in_msg(child=child):
         next_parts = name_error_parts
 
     elif name_error_msg in before:
         next_parts = bp_forev_parts
 
     else:
-        raise ValueError("Neither log msg was found !?")
+        raise ValueError('Neither log msg was found !?')
 
     if ctlc:
         do_ctlc(child)
@@ -746,14 +569,12 @@ def test_multi_daemon_subactors(
     # wait for final error in root
     # where it crashs with boxed error
     while True:
-        try:
         child.sendline('c')
         child.expect(PROMPT)
-            assert_before(
+        if not in_prompt_msg(
             child,
             bp_forev_parts
-            )
-        except AssertionError:
+        ):
             break
 
     assert_before(
@@ -769,7 +590,7 @@ def test_multi_daemon_subactors(
     )
 
     child.sendline('c')
-    child.expect(pexpect.EOF)
+    child.expect(EOF)
 
 
 @has_nested_actors
@@ -845,7 +666,7 @@ def test_multi_subactors_root_errors(
     ])
 
     child.sendline('c')
-    child.expect(pexpect.EOF)
+    child.expect(EOF)
 
     assert_before(child, [
         # "Attaching to pdb in crashed actor: ('root'",
@@ -934,10 +755,13 @@ def test_root_nursery_cancels_before_child_releases_tty_lock(
     child = spawn('root_cancelled_but_child_is_in_tty_lock')
 
     child.expect(PROMPT)
-
-    before = str(child.before.decode())
-    assert "NameError: name 'doggypants' is not defined" in before
-    assert "tractor._exceptions.RemoteActorError: ('name_error'" not in before
+    assert_before(
+        child,
+        [
+            "NameError: name 'doggypants' is not defined",
+            "tractor._exceptions.RemoteActorError: ('name_error'",
+        ],
+    )
     time.sleep(0.5)
 
     if ctlc:
@@ -975,7 +799,7 @@ def test_root_nursery_cancels_before_child_releases_tty_lock(
 
     for i in range(3):
         try:
-            child.expect(pexpect.EOF, timeout=0.5)
+            child.expect(EOF, timeout=0.5)
             break
         except TIMEOUT:
             child.sendline('c')
@@ -1017,7 +841,7 @@ def test_root_cancels_child_context_during_startup(
         do_ctlc(child)
 
     child.sendline('c')
-    child.expect(pexpect.EOF)
+    child.expect(EOF)
 
 
 def test_different_debug_mode_per_actor(
@@ -1028,9 +852,8 @@ def test_different_debug_mode_per_actor(
     child.expect(PROMPT)
 
     # only one actor should enter the debugger
-    before = str(child.before.decode())
     assert in_prompt_msg(
-        before,
+        child,
         [_crash_msg, "('debugged_boi'", "RuntimeError"],
     )
 
@@ -1038,9 +861,7 @@ def test_different_debug_mode_per_actor(
         do_ctlc(child)
 
     child.sendline('c')
-    child.expect(pexpect.EOF)
-
-    before = str(child.before.decode())
+    child.expect(EOF)
 
     # NOTE: this debugged actor error currently WON'T show up since the
     # root will actually cancel and terminate the nursery before the error
@@ -1059,103 +880,6 @@ def test_different_debug_mode_per_actor(
     )
 
 
-def test_pause_from_sync(
-    spawn,
-    ctlc: bool
-):
-    '''
-    Verify we can use the `pdbp` REPL from sync functions AND from
-    any thread spawned with `trio.to_thread.run_sync()`.
-
-    `examples/debugging/sync_bp.py`
-
-    '''
-    child = spawn('sync_bp')
-
-    # first `sync_pause()` after nurseries open
-    child.expect(PROMPT)
-    assert_before(
-        child,
-        [
-            # pre-prompt line
-            _pause_msg,
-            "<Task '__main__.main'",
-            "('root'",
-        ]
-    )
-    if ctlc:
-        do_ctlc(child)
-
-    child.sendline('c')
-
-
-    # first `await tractor.pause()` inside `p.open_context()` body
-    child.expect(PROMPT)
-
-    # XXX shouldn't see gb loaded message with PDB loglevel!
-    before = str(child.before.decode())
-    assert not in_prompt_msg(
-        before,
-        ['`greenback` portal opened!'],
-    )
-    # should be same root task
-    assert_before(
-        child,
-        [
-            _pause_msg,
-            "<Task '__main__.main'",
-            "('root'",
-        ]
-    )
-
-    if ctlc:
-        do_ctlc(child)
-
-    # one of the bg thread or subactor should have
-    # `Lock.acquire()`-ed
-    # (NOT both, which will result in REPL clobbering!)
-    attach_patts: dict[str, list[str]] = {
-        'subactor': [
-            "'start_n_sync_pause'",
-            "('subactor'",
-        ],
-        'inline_root_bg_thread': [
-            "<Thread(inline_root_bg_thread",
-            "('root'",
-        ],
-        'start_soon_root_bg_thread': [
-            "<Thread(start_soon_root_bg_thread",
-            "('root'",
-        ],
-    }
-    while attach_patts:
-        child.sendline('c')
-        child.expect(PROMPT)
-        before = str(child.before.decode())
-        for key in attach_patts.copy():
-            if key in before:
-                expected_patts: str = attach_patts.pop(key)
-                assert_before(
-                    child,
-                    [_pause_msg] + expected_patts
-                )
-                break
-
-        # ensure no other task/threads engaged a REPL
-        # at the same time as the one that was detected above.
-        for key, other_patts in attach_patts.items():
-            assert not in_prompt_msg(
-                before,
-                other_patts,
-            )
-
-        if ctlc:
-            do_ctlc(child)
-
-    child.sendline('c')
-    child.expect(pexpect.EOF)
-
-
 def test_post_mortem_api(
     spawn,
     ctlc: bool,
@@ -1258,7 +982,7 @@ def test_post_mortem_api(
     # )
 
     child.sendline('c')
-    child.expect(pexpect.EOF)
+    child.expect(EOF)
 
 
 def test_shield_pause(
@@ -1333,9 +1057,26 @@ def test_shield_pause(
         ]
     )
     child.sendline('c')
-    child.expect(pexpect.EOF)
+    child.expect(EOF)
 
 
+# TODO: better error for "non-ideal" usage from the root actor.
+# -[ ] if called from an async scope emit a message that suggests
+#    using `await tractor.pause()` instead since it's less overhead
+#    (in terms of `greenback` and/or extra threads) and if it's from
+#    a sync scope suggest that usage must first call
+#    `ensure_portal()` in the (eventual parent) async calling scope?
+def test_sync_pause_from_bg_task_in_root_actor_():
+    '''
+    When used from the root actor, normally we can only implicitly
+    support `.pause_from_sync()` from the main-parent-task (that
+    opens the runtime via `open_root_actor()`) since `greenback`
+    requires a `.ensure_portal()` call per `trio.Task` where it is
+    used.
+
+    '''
+    ...
+
 # TODO: needs ANSI code stripping tho, see `assert_before()` # above!
 def test_correct_frames_below_hidden():
     '''

tests/devx/test_pause_from_non_trio.py

@@ -0,0 +1,329 @@
+'''
+That "foreign loop/thread" debug REPL support better ALSO WORK!
+
+Same as `test_native_pause.py`.
+All these tests can be understood (somewhat) by running the
+equivalent `examples/debugging/` scripts manually.
+
+'''
+# from functools import partial
+# import itertools
+import time
+# from typing import (
+#     Iterator,
+# )
+
+import pytest
+from pexpect.exceptions import (
+    # TIMEOUT,
+    EOF,
+)
+
+from .conftest import (
+    # _ci_env,
+    do_ctlc,
+    PROMPT,
+    # expect,
+    in_prompt_msg,
+    assert_before,
+    _pause_msg,
+    _crash_msg,
+    _ctlc_ignore_header,
+    # _repl_fail_msg,
+)
+
+
+def test_pause_from_sync(
+    spawn,
+    ctlc: bool,
+):
+    '''
+    Verify we can use the `pdbp` REPL from sync functions AND from
+    any thread spawned with `trio.to_thread.run_sync()`.
+
+    `examples/debugging/sync_bp.py`
+
+    '''
+    child = spawn('sync_bp')
+
+    # first `sync_pause()` after nurseries open
+    child.expect(PROMPT)
+    assert_before(
+        child,
+        [
+            # pre-prompt line
+            _pause_msg,
+            "<Task '__main__.main'",
+            "('root'",
+        ]
+    )
+    if ctlc:
+        do_ctlc(child)
+        # ^NOTE^ subactor not spawned yet; don't need extra delay.
+
+    child.sendline('c')
+
+    # first `await tractor.pause()` inside `p.open_context()` body
+    child.expect(PROMPT)
+
+    # XXX shouldn't see gb loaded message with PDB loglevel!
+    assert not in_prompt_msg(
+        child,
+        ['`greenback` portal opened!'],
+    )
+    # should be same root task
+    assert_before(
+        child,
+        [
+            _pause_msg,
+            "<Task '__main__.main'",
+            "('root'",
+        ]
+    )
+
+    if ctlc:
+        do_ctlc(
+            child,
+            # NOTE: setting this to 0 (or some other sufficient
+            # small val) can cause the test to fail since the
+            # `subactor` suffers a race where the root/parent
+            # sends an actor-cancel prior to it hitting its pause
+            # point; by def the value is 0.1
+            delay=0.4,
+        )
+
+    # XXX, fwiw without a brief sleep here the SIGINT might actually
+    # trigger "subactor" cancellation by its parent  before the
+    # shield-handler is engaged.
+    #
+    # => similar to the `delay` input to `do_ctlc()` below, setting
+    # this too low can cause the test to fail since the `subactor`
+    # suffers a race where the root/parent sends an actor-cancel
+    # prior to the context task hitting its pause point (and thus
+    # engaging the `sigint_shield()` handler in time); this value
+    # seems be good enuf?
+    time.sleep(0.6)
+
+    # one of the bg thread or subactor should have
+    # `Lock.acquire()`-ed
+    # (NOT both, which will result in REPL clobbering!)
+    attach_patts: dict[str, list[str]] = {
+        'subactor': [
+            "'start_n_sync_pause'",
+            "('subactor'",
+        ],
+        'inline_root_bg_thread': [
+            "<Thread(inline_root_bg_thread",
+            "('root'",
+        ],
+        'start_soon_root_bg_thread': [
+            "<Thread(start_soon_root_bg_thread",
+            "('root'",
+        ],
+    }
+    conts: int = 0  # for debugging below matching logic on failure
+    while attach_patts:
+        child.sendline('c')
+        conts += 1
+        child.expect(PROMPT)
+        before = str(child.before.decode())
+        for key in attach_patts:
+            if key in before:
+                attach_key: str = key
+                expected_patts: str = attach_patts.pop(key)
+                assert_before(
+                    child,
+                    [_pause_msg]
+                    +
+                    expected_patts
+                )
+                break
+        else:
+            pytest.fail(
+                f'No keys found?\n\n'
+                f'{attach_patts.keys()}\n\n'
+                f'{before}\n'
+            )
+
+        # ensure no other task/threads engaged a REPL
+        # at the same time as the one that was detected above.
+        for key, other_patts in attach_patts.copy().items():
+            assert not in_prompt_msg(
+                child,
+                other_patts,
+            )
+
+        if ctlc:
+            do_ctlc(
+                child,
+                patt=attach_key,
+                # NOTE same as comment above
+                delay=0.4,
+            )
+
+    child.sendline('c')
+    child.expect(EOF)
+
+
+def expect_any_of(
+    attach_patts: dict[str, list[str]],
+    child,   # what type?
+    ctlc: bool = False,
+    prompt: str = _ctlc_ignore_header,
+    ctlc_delay: float = .4,
+
+) -> list[str]:
+    '''
+    Receive any of a `list[str]` of patterns provided in
+    `attach_patts`.
+
+    Used to test racing prompts from multiple actors and/or
+    tasks using a common root process' `pdbp` REPL.
+
+    '''
+    assert attach_patts
+
+    child.expect(PROMPT)
+    before = str(child.before.decode())
+
+    for attach_key in attach_patts:
+        if attach_key in before:
+            expected_patts: str = attach_patts.pop(attach_key)
+            assert_before(
+                child,
+                expected_patts
+            )
+            break  # from for
+    else:
+        pytest.fail(
+            f'No keys found?\n\n'
+            f'{attach_patts.keys()}\n\n'
+            f'{before}\n'
+        )
+
+    # ensure no other task/threads engaged a REPL
+    # at the same time as the one that was detected above.
+    for key, other_patts in attach_patts.copy().items():
+        assert not in_prompt_msg(
+            child,
+            other_patts,
+        )
+
+    if ctlc:
+        do_ctlc(
+            child,
+            patt=prompt,
+            # NOTE same as comment above
+            delay=ctlc_delay,
+        )
+
+    return expected_patts
+    # yield child
+
+
+def test_pause_from_asyncio_task(
+    spawn,
+    ctlc: bool
+    # ^TODO, fix for `asyncio`!!
+):
+    '''
+    Verify we can use the `pdbp` REPL from an `asyncio.Task` spawned using
+    APIs in `.to_asyncio`.
+
+    `examples/debugging/asycio_bp.py`
+
+    '''
+    child = spawn('asyncio_bp')
+
+    # RACE on whether trio/asyncio task bps first
+    attach_patts: dict[str, list[str]] = {
+
+        # first pause in guest-mode (aka "infecting")
+        # `trio.Task`.
+        'trio-side': [
+            _pause_msg,
+            "<Task 'trio_ctx'",
+            "('aio_daemon'",
+        ],
+
+        # `breakpoint()` from `asyncio.Task`.
+        'asyncio-side': [
+            _pause_msg,
+            "<Task pending name='Task-2' coro=<greenback_shim()",
+            "('aio_daemon'",
+        ],
+    }
+
+    while attach_patts:
+        expect_any_of(
+            attach_patts=attach_patts,
+            child=child,
+            ctlc=ctlc,
+        )
+        child.sendline('c')
+
+    # NOW in race order,
+    # - the asyncio-task will error
+    # - the root-actor parent task will pause
+    #
+    attach_patts: dict[str, list[str]] = {
+
+        # error raised in `asyncio.Task`
+        "raise ValueError('asyncio side error!')": [
+            _crash_msg,
+            'return await chan.receive()',  # `.to_asyncio` impl internals in tb
+            "<Task 'trio_ctx'",
+            "@ ('aio_daemon'",
+            "ValueError: asyncio side error!",
+        ],
+
+        # parent-side propagation via actor-nursery/portal
+        # "tractor._exceptions.RemoteActorError: remote task raised a 'ValueError'": [
+        "remote task raised a 'ValueError'": [
+            _crash_msg,
+            "src_uid=('aio_daemon'",
+            "('aio_daemon'",
+        ],
+
+        # a final pause in root-actor
+        "<Task '__main__.main'": [
+            _pause_msg,
+            "<Task '__main__.main'",
+            "('root'",
+        ],
+    }
+    while attach_patts:
+        expect_any_of(
+            attach_patts=attach_patts,
+            child=child,
+            ctlc=ctlc,
+        )
+        child.sendline('c')
+
+    assert not attach_patts
+
+    # final boxed error propagates to root
+    assert_before(
+        child,
+        [
+            _crash_msg,
+            "<Task '__main__.main'",
+            "('root'",
+            "remote task raised a 'ValueError'",
+            "ValueError: asyncio side error!",
+        ]
+    )
+
+    if ctlc:
+        do_ctlc(
+            child,
+            # NOTE: setting this to 0 (or some other sufficient
+            # small val) can cause the test to fail since the
+            # `subactor` suffers a race where the root/parent
+            # sends an actor-cancel prior to it hitting its pause
+            # point; by def the value is 0.1
+            delay=0.4,
+        )
+
+    child.sendline('c')
+    child.expect(EOF)

tests/devx/test_tooling.py

@@ -0,0 +1,120 @@
+'''
+That "native" runtime-hackin toolset better be dang useful!
+
+Verify the funtion of a variety of "developer-experience" tools we
+offer from the `.devx` sub-pkg:
+
+- use of the lovely `stackscope` for dumping actor `trio`-task trees
+  during operation and hangs.
+
+TODO:
+- demonstration of `CallerInfo` call stack frame filtering such that
+  for logging and REPL purposes a user sees exactly the layers needed
+  when debugging a problem inside the stack vs. in their app.
+
+'''
+import os
+import signal
+
+from .conftest import (
+    expect,
+    assert_before,
+    # in_prompt_msg,
+)
+
+
+def test_shield_pause(
+    spawn,
+):
+    '''
+    Verify the `tractor.pause()/.post_mortem()` API works inside an
+    already cancelled `trio.CancelScope` and that you can step to the
+    next checkpoint wherein the cancelled will get raised.
+
+    '''
+    child = spawn(
+        'shield_hang_in_sub'
+    )
+    expect(
+        child,
+        'Yo my child hanging..?',
+    )
+    assert_before(
+        child,
+        [
+            'Entering shield sleep..',
+            'Enabling trace-trees on `SIGUSR1` since `stackscope` is installed @',
+        ]
+    )
+
+    print(
+        'Sending SIGUSR1 to see a tree-trace!',
+    )
+    os.kill(
+        child.pid,
+        signal.SIGUSR1,
+    )
+    expect(
+        child,
+        # end-of-tree delimiter
+        "------ \('root', ",
+    )
+
+    assert_before(
+        child,
+        [
+            'Trying to dump `stackscope` tree..',
+            'Dumping `stackscope` tree for actor',
+            "('root'",  # uid line
+
+            # parent block point (non-shielded)
+            'await trio.sleep_forever()  # in root',
+        ]
+    )
+
+    # expect(
+    #     child,
+    #     # relay to the sub should be reported
+    #     'Relaying `SIGUSR1`[10] to sub-actor',
+    # )
+
+    expect(
+        child,
+        # end-of-tree delimiter
+        "------ \('hanger', ",
+    )
+    assert_before(
+        child,
+        [
+            # relay to the sub should be reported
+            'Relaying `SIGUSR1`[10] to sub-actor',
+
+            "('hanger'",  # uid line
+
+            # hanger LOC where it's shield-halted
+            'await trio.sleep_forever()  # in subactor',
+        ]
+    )
+    # breakpoint()
+
+    # simulate the user sending a ctl-c to the hanging program.
+    # this should result in the terminator kicking in since
+    # the sub is shield blocking and can't respond to SIGINT.
+    os.kill(
+        child.pid,
+        signal.SIGINT,
+    )
+    expect(
+        child,
+        'Shutting down actor runtime',
+        timeout=6,
+    )
+    assert_before(
+        child,
+        [
+            'raise KeyboardInterrupt',
+            # 'Shutting down actor runtime',
+            '#T-800 deployed to collect zombie B0',
+            "'--uid', \"('hanger',",
+        ]
+    )

tests/test_advanced_faults.py

@@ -91,7 +91,8 @@ def test_ipc_channel_break_during_stream(
 
         # non-`trio` spawners should never hit the hang condition that
         # requires the user to do ctl-c to cancel the actor tree.
-        expect_final_exc = trio.ClosedResourceError
+        # expect_final_exc = trio.ClosedResourceError
+        expect_final_exc = tractor.TransportClosed
 
     mod: ModuleType = import_path(
         examples_dir() / 'advanced_faults'
@@ -157,7 +158,7 @@ def test_ipc_channel_break_during_stream(
         if pre_aclose_msgstream:
             expect_final_exc = KeyboardInterrupt
 
-    # NOTE when the parent IPC side dies (even if the child's does as well
+    # NOTE when the parent IPC side dies (even if the child does as well
     # but the child fails BEFORE the parent) we always expect the
     # IPC layer to raise a closed-resource, NEVER do we expect
     # a stop msg since the parent-side ctx apis will error out
@@ -169,7 +170,8 @@ def test_ipc_channel_break_during_stream(
         and
         ipc_break['break_child_ipc_after'] is False
     ):
-        expect_final_exc = trio.ClosedResourceError
+        # expect_final_exc = trio.ClosedResourceError
+        expect_final_exc = tractor.TransportClosed
 
     # BOTH but, PARENT breaks FIRST
     elif (
@@ -180,7 +182,8 @@ def test_ipc_channel_break_during_stream(
             ipc_break['break_parent_ipc_after']
         )
     ):
-        expect_final_exc = trio.ClosedResourceError
+        # expect_final_exc = trio.ClosedResourceError
+        expect_final_exc = tractor.TransportClosed
 
     with pytest.raises(
         expected_exception=(
@@ -199,8 +202,8 @@ def test_ipc_channel_break_during_stream(
                     **ipc_break,
                 )
             )
-        except KeyboardInterrupt as kbi:
-            _err = kbi
+        except KeyboardInterrupt as _kbi:
+            kbi = _kbi
             if expect_final_exc is not KeyboardInterrupt:
                 pytest.fail(
                     'Rxed unexpected KBI !?\n'
@@ -209,6 +212,21 @@ def test_ipc_channel_break_during_stream(
 
             raise
 
+        except tractor.TransportClosed as _tc:
+            tc = _tc
+            if expect_final_exc is KeyboardInterrupt:
+                pytest.fail(
+                    'Unexpected transport failure !?\n'
+                    f'{repr(tc)}'
+                )
+            cause: Exception = tc.__cause__
+            assert (
+                type(cause) is trio.ClosedResourceError
+                and
+                cause.args[0] == 'another task closed this fd'
+            )
+            raise
+
     # get raw instance from pytest wrapper
     value = excinfo.value
     if isinstance(value, ExceptionGroup):

tests/test_caps_based_msging.py

@@ -11,9 +11,6 @@ from typing import (
     Type,
     Union,
 )
-from contextvars import (
-    Context,
-)
 
 from msgspec import (
     structs,
@@ -27,6 +24,7 @@ import tractor
 from tractor import (
     _state,
     MsgTypeError,
+    Context,
 )
 from tractor.msg import (
     _codec,
@@ -41,7 +39,7 @@ from tractor.msg import (
 from tractor.msg.types import (
     _payload_msgs,
     log,
-    Msg,
+    PayloadMsg,
     Started,
     mk_msg_spec,
 )
@@ -61,7 +59,7 @@ def mk_custom_codec(
     uid: tuple[str, str] = tractor.current_actor().uid
 
     # XXX NOTE XXX: despite defining `NamespacePath` as a type
-    # field on our `Msg.pld`, we still need a enc/dec_hook() pair
+    # field on our `PayloadMsg.pld`, we still need a enc/dec_hook() pair
     # to cast to/from that type on the wire. See the docs:
     # https://jcristharif.com/msgspec/extending.html#mapping-to-from-native-types
 
@@ -321,12 +319,12 @@ def dec_type_union(
     import importlib
     types: list[Type] = []
     for type_name in type_names:
-        for ns in [
+        for mod in [
             typing,
             importlib.import_module(__name__),
         ]:
             if type_ref := getattr(
-                ns,
+                mod,
                 type_name,
                 False,
             ):
@@ -744,7 +742,7 @@ def chk_pld_type(
     # 'Error',  .pld: ErrorData
 
     codec: MsgCodec = mk_codec(
-        # NOTE: this ONLY accepts `Msg.pld` fields of a specified
+        # NOTE: this ONLY accepts `PayloadMsg.pld` fields of a specified
         # type union.
         ipc_pld_spec=payload_spec,
     )
@@ -752,7 +750,7 @@ def chk_pld_type(
     # make a one-off dec to compare with our `MsgCodec` instance
     # which does the below `mk_msg_spec()` call internally
     ipc_msg_spec: Union[Type[Struct]]
-    msg_types: list[Msg[payload_spec]]
+    msg_types: list[PayloadMsg[payload_spec]]
     (
         ipc_msg_spec,
         msg_types,
@@ -761,7 +759,7 @@ def chk_pld_type(
     )
     _enc = msgpack.Encoder()
     _dec = msgpack.Decoder(
-        type=ipc_msg_spec or Any,  # like `Msg[Any]`
+        type=ipc_msg_spec or Any,  # like `PayloadMsg[Any]`
     )
 
     assert (
@@ -806,7 +804,7 @@ def chk_pld_type(
             'cid': '666',
             'pld': pld,
         }
-        enc_msg: Msg = typedef(**kwargs)
+        enc_msg: PayloadMsg = typedef(**kwargs)
 
         _wire_bytes: bytes = _enc.encode(enc_msg)
         wire_bytes: bytes = codec.enc.encode(enc_msg)
@@ -883,25 +881,16 @@ def test_limit_msgspec():
             debug_mode=True
         ):
 
-            # ensure we can round-trip a boxing `Msg`
+            # ensure we can round-trip a boxing `PayloadMsg`
             assert chk_pld_type(
-                # Msg,
-                Any,
-                None,
+                payload_spec=Any,
+                pld=None,
                 expect_roundtrip=True,
             )
 
-            # TODO: don't need this any more right since
-            # `msgspec>=0.15` has the nice generics stuff yah??
-            #
-            # manually override the type annot of the payload
-            # field and ensure it propagates to all msg-subtypes.
-            # Msg.__annotations__['pld'] = Any
-
             # verify that a mis-typed payload value won't decode
             assert not chk_pld_type(
-                # Msg,
-                int,
+                payload_spec=int,
                 pld='doggy',
             )
 
@@ -913,18 +902,16 @@ def test_limit_msgspec():
                 value: Any
 
             assert not chk_pld_type(
-                # Msg,
-                CustomPayload,
+                payload_spec=CustomPayload,
                 pld='doggy',
             )
 
             assert chk_pld_type(
-                # Msg,
-                CustomPayload,
+                payload_spec=CustomPayload,
                 pld=CustomPayload(name='doggy', value='urmom')
             )
 
-            # uhh bc we can `.pause_from_sync()` now! :surfer:
+            # yah, we can `.pause_from_sync()` now!
             # breakpoint()
 
     trio.run(main)

tests/test_context_stream_semantics.py

@@ -955,7 +955,7 @@ async def echo_back_sequence(
     )
 
     await ctx.started()
-    # await tractor.breakpoint()
+    # await tractor.pause()
     async with ctx.open_stream(
         msg_buffer_size=msg_buffer_size,
 

tests/test_discovery.py

@@ -26,7 +26,7 @@ async def test_reg_then_unreg(reg_addr):
         portal = await n.start_actor('actor', enable_modules=[__name__])
         uid = portal.channel.uid
 
-        async with tractor.get_arbiter(*reg_addr) as aportal:
+        async with tractor.get_registry(*reg_addr) as aportal:
             # this local actor should be the arbiter
             assert actor is aportal.actor
 
@@ -160,7 +160,7 @@ async def spawn_and_check_registry(
     async with tractor.open_root_actor(
         registry_addrs=[reg_addr],
     ):
-        async with tractor.get_arbiter(*reg_addr) as portal:
+        async with tractor.get_registry(*reg_addr) as portal:
             # runtime needs to be up to call this
             actor = tractor.current_actor()
 
@@ -298,7 +298,7 @@ async def close_chans_before_nursery(
     async with tractor.open_root_actor(
         registry_addrs=[reg_addr],
     ):
-        async with tractor.get_arbiter(*reg_addr) as aportal:
+        async with tractor.get_registry(*reg_addr) as aportal:
             try:
                 get_reg = partial(unpack_reg, aportal)
 

tests/test_docs_examples.py

@@ -19,7 +19,7 @@ from tractor._testing import (
 @pytest.fixture
 def run_example_in_subproc(
     loglevel: str,
-    testdir,
+    testdir: pytest.Testdir,
     reg_addr: tuple[str, int],
 ):
 

tests/test_infected_asyncio.py

@@ -2,19 +2,30 @@
 The hipster way to force SC onto the stdlib's "async": 'infection mode'.
 
 '''
-from typing import Optional, Iterable, Union
 import asyncio
 import builtins
+from contextlib import ExitStack
 import itertools
 import importlib
+import os
+from pathlib import Path
+import signal
+from typing import (
+    Callable,
+    Iterable,
+    Union,
+)
 
 import pytest
 import trio
 import tractor
 from tractor import (
+    current_actor,
+    Actor,
     to_asyncio,
     RemoteActorError,
     ContextCancelled,
+    _state,
 )
 from tractor.trionics import BroadcastReceiver
 from tractor._testing import expect_ctxc
@@ -25,8 +36,8 @@ async def sleep_and_err(
 
     # just signature placeholders for compat with
     # ``to_asyncio.open_channel_from()``
-    to_trio: Optional[trio.MemorySendChannel] = None,
-    from_trio: Optional[asyncio.Queue] = None,
+    to_trio: trio.MemorySendChannel|None = None,
+    from_trio: asyncio.Queue|None = None,
 
 ):
     if to_trio:
@@ -36,7 +47,7 @@ async def sleep_and_err(
     assert 0
 
 
-async def sleep_forever():
+async def aio_sleep_forever():
     await asyncio.sleep(float('inf'))
 
 
@@ -44,7 +55,7 @@ async def trio_cancels_single_aio_task():
 
     # spawn an ``asyncio`` task to run a func and return result
     with trio.move_on_after(.2):
-        await tractor.to_asyncio.run_task(sleep_forever)
+        await tractor.to_asyncio.run_task(aio_sleep_forever)
 
 
 def test_trio_cancels_aio_on_actor_side(reg_addr):
@@ -66,14 +77,22 @@ def test_trio_cancels_aio_on_actor_side(reg_addr):
 
 
 async def asyncio_actor(
-
     target: str,
     expect_err: Exception|None = None
 
 ) -> None:
 
-    assert tractor.current_actor().is_infected_aio()
-    target = globals()[target]
+    # ensure internal runtime state is consistent
+    actor: Actor = tractor.current_actor()
+    assert (
+        actor.is_infected_aio()
+        and
+        actor._infected_aio
+        and
+        _state._runtime_vars['_is_infected_aio']
+    )
+
+    target: Callable = globals()[target]
 
     if '.' in expect_err:
         modpath, _, name = expect_err.rpartition('.')
@@ -128,7 +147,7 @@ def test_aio_simple_error(reg_addr):
         assert err
 
     assert isinstance(err, RemoteActorError)
-    assert err.boxed_type == AssertionError
+    assert err.boxed_type is AssertionError
 
 
 def test_tractor_cancels_aio(reg_addr):
@@ -140,7 +159,7 @@ def test_tractor_cancels_aio(reg_addr):
         async with tractor.open_nursery() as n:
             portal = await n.run_in_actor(
                 asyncio_actor,
-                target='sleep_forever',
+                target='aio_sleep_forever',
                 expect_err='trio.Cancelled',
                 infect_asyncio=True,
             )
@@ -164,7 +183,7 @@ def test_trio_cancels_aio(reg_addr):
             async with tractor.open_nursery() as n:
                 await n.run_in_actor(
                     asyncio_actor,
-                    target='sleep_forever',
+                    target='aio_sleep_forever',
                     expect_err='trio.Cancelled',
                     infect_asyncio=True,
                 )
@@ -195,7 +214,7 @@ async def trio_ctx(
             # spawn another asyncio task for the cuck of it.
             n.start_soon(
                 tractor.to_asyncio.run_task,
-                sleep_forever,
+                aio_sleep_forever,
             )
             await trio.sleep_forever()
 
@@ -272,7 +291,7 @@ def test_context_spawns_aio_task_that_errors(
 
         err = excinfo.value
         assert isinstance(err, expect)
-        assert err.boxed_type == AssertionError
+        assert err.boxed_type is AssertionError
 
 
 async def aio_cancel():
@@ -281,23 +300,35 @@ async def aio_cancel():
 
     '''
     await asyncio.sleep(0.5)
-    task = asyncio.current_task()
 
     # cancel and enter sleep
+    task = asyncio.current_task()
     task.cancel()
-    await sleep_forever()
+    await aio_sleep_forever()
 
 
 def test_aio_cancelled_from_aio_causes_trio_cancelled(reg_addr):
+    '''
+    When the `asyncio.Task` cancels itself the `trio` side cshould
+    also cancel and teardown and relay the cancellation cross-process
+    to the caller (parent).
 
+    '''
     async def main():
-        async with tractor.open_nursery() as n:
-            await n.run_in_actor(
+
+        an: tractor.ActorNursery
+        async with tractor.open_nursery() as an:
+            p: tractor.Portal = await an.run_in_actor(
                 asyncio_actor,
                 target='aio_cancel',
                 expect_err='tractor.to_asyncio.AsyncioCancelled',
                 infect_asyncio=True,
             )
+            # NOTE: normally the `an.__aexit__()` waits on the
+            # portal's result but we do it explicitly here
+            # to avoid indent levels.
+            with trio.fail_after(1):
+                await p.wait_for_result()
 
     with pytest.raises(
         expected_exception=(RemoteActorError, ExceptionGroup),
@@ -305,7 +336,7 @@ def test_aio_cancelled_from_aio_causes_trio_cancelled(reg_addr):
         trio.run(main)
 
     # might get multiple `trio.Cancelled`s as well inside an inception
-    err = excinfo.value
+    err: RemoteActorError|ExceptionGroup = excinfo.value
     if isinstance(err, ExceptionGroup):
         err = next(itertools.dropwhile(
             lambda exc: not isinstance(exc, tractor.RemoteActorError),
@@ -313,7 +344,8 @@ def test_aio_cancelled_from_aio_causes_trio_cancelled(reg_addr):
         ))
         assert err
 
-    # ensure boxed error is correct
+    # relayed boxed error should be our `trio`-task's
+    # cancel-signal-proxy-equivalent of `asyncio.CancelledError`.
     assert err.boxed_type == to_asyncio.AsyncioCancelled
 
 
@@ -355,7 +387,6 @@ async def push_from_aio_task(
 
 
 async def stream_from_aio(
-
     exit_early: bool = False,
     raise_err: bool = False,
     aio_raise_err: bool = False,
@@ -466,7 +497,7 @@ def test_trio_error_cancels_intertask_chan(reg_addr):
         trio.run(main)
 
     # ensure boxed error type
-    excinfo.value.boxed_type == Exception
+    excinfo.value.boxed_type is Exception
 
 
 def test_trio_closes_early_and_channel_exits(reg_addr):
@@ -502,7 +533,7 @@ def test_aio_errors_and_channel_propagates_and_closes(reg_addr):
     ) as excinfo:
         trio.run(main)
 
-    excinfo.value.boxed_type == Exception
+    excinfo.value.boxed_type is Exception
 
 
 @tractor.context
@@ -618,6 +649,242 @@ def test_echoserver_detailed_mechanics(
         trio.run(main)
 
 
+
+@tractor.context
+async def manage_file(
+    ctx: tractor.Context,
+    tmp_path_str: str,
+    send_sigint_to: str,
+    trio_side_is_shielded: bool = True,
+    bg_aio_task: bool = False,
+):
+    '''
+    Start an `asyncio` task that just sleeps after registering a context
+    with `Actor.lifetime_stack`. Trigger a SIGINT to kill the actor tree
+    and ensure the stack is closed in the infected mode child.
+
+    To verify the teardown state just write a tmpfile to the `testdir`
+    and delete it on actor close.
+
+    '''
+
+    tmp_path: Path = Path(tmp_path_str)
+    tmp_file: Path = tmp_path / f'{" ".join(ctx._actor.uid)}.file'
+
+    # create a the tmp file and tell the parent where it's at
+    assert not tmp_file.is_file()
+    tmp_file.touch()
+
+    stack: ExitStack = current_actor().lifetime_stack
+    stack.callback(tmp_file.unlink)
+
+    await ctx.started((
+        str(tmp_file),
+        os.getpid(),
+    ))
+
+    # expect to be cancelled from here!
+    try:
+
+        # NOTE: turns out you don't even need to sched an aio task
+        # since the original issue, even though seemingly was due to
+        # the guest-run being abandoned + a `._debug.pause()` inside
+        # `._runtime._async_main()` (which was originally trying to
+        # debug the `.lifetime_stack` not closing), IS NOT actually
+        # the core issue?
+        #
+        # further notes:
+        #
+        # - `trio` only issues the " RuntimeWarning: Trio guest run
+        #   got abandoned without properly finishing... weird stuff
+        #   might happen" IFF you DO run a asyncio task here, BUT
+        # - the original issue of the `.lifetime_stack` not closing
+        #   will still happen even if you don't run an `asyncio` task
+        #   here even though the "abandon" messgage won't be shown..
+        #
+        # => ????? honestly i'm lost but it seems to be some issue
+        #   with `asyncio` and SIGINT..
+        #
+        # honestly, this REALLY reminds me why i haven't used
+        # `asyncio` by choice in years.. XD
+        #
+        async with trio.open_nursery() as tn:
+            if bg_aio_task:
+                tn.start_soon(
+                    tractor.to_asyncio.run_task,
+                    aio_sleep_forever,
+                )
+
+            # XXX don't-need/doesn't-make-a-diff right
+            # since we're already doing it from parent?
+            # if send_sigint_to == 'child':
+            #     os.kill(
+            #         os.getpid(),
+            #         signal.SIGINT,
+            #     )
+
+            # XXX spend a half sec doing shielded checkpointing to
+            # ensure that despite the `trio`-side task ignoring the
+            # SIGINT, the `asyncio` side won't abandon the guest-run!
+            if trio_side_is_shielded:
+                with trio.CancelScope(shield=True):
+                    for i in range(5):
+                        await trio.sleep(0.1)
+
+            await trio.sleep_forever()
+
+    # signalled manually at the OS level (aka KBI) by the parent actor.
+    except KeyboardInterrupt:
+        print('child raised KBI..')
+        assert tmp_file.exists()
+        raise
+
+    raise RuntimeError('shoulda received a KBI?')
+
+
+@pytest.mark.parametrize(
+    'trio_side_is_shielded',
+    [
+        False,
+        True,
+    ],
+    ids=[
+        'trio_side_no_shielding',
+        'trio_side_does_shielded_work',
+    ],
+)
+@pytest.mark.parametrize(
+    'send_sigint_to',
+    [
+        'child',
+        'parent',
+    ],
+    ids='send_SIGINT_to={}'.format,
+)
+@pytest.mark.parametrize(
+    'bg_aio_task',
+    [
+        False,
+
+        # NOTE: (and see notes in `manage_file()` above as well) if
+        # we FOR SURE SPAWN AN AIO TASK in the child it seems the
+        # "silent-abandon" case (as is described in detail in
+        # `to_asyncio.run_as_asyncio_guest()`) does not happen and
+        # `asyncio`'s loop will at least abandon the `trio` side
+        # loudly? .. prolly the state-spot to start looking for
+        # a soln that results in NO ABANDONMENT.. XD
+        True,
+    ],
+    ids=[
+        'bg_aio_task',
+        'just_trio_slee',
+    ],
+)
+@pytest.mark.parametrize(
+    'wait_for_ctx',
+    [
+        False,
+        True,
+    ],
+    ids=[
+        'raise_KBI_in_rent',
+        'wait_for_ctx',
+    ],
+)
+def test_sigint_closes_lifetime_stack(
+    tmp_path: Path,
+    wait_for_ctx: bool,
+    bg_aio_task: bool,
+    trio_side_is_shielded: bool,
+    debug_mode: bool,
+    send_sigint_to: str,
+):
+    '''
+    Ensure that an infected child can use the `Actor.lifetime_stack`
+    to make a file on boot and it's automatically cleaned up by the
+    actor-lifetime-linked exit stack closure.
+
+    '''
+    async def main():
+        try:
+            an: tractor.ActorNursery
+            async with tractor.open_nursery(
+                debug_mode=debug_mode,
+            ) as an:
+                p: tractor.Portal = await an.start_actor(
+                    'file_mngr',
+                    enable_modules=[__name__],
+                    infect_asyncio=True,
+                )
+                async with p.open_context(
+                    manage_file,
+                    tmp_path_str=str(tmp_path),
+                    send_sigint_to=send_sigint_to,
+                    bg_aio_task=bg_aio_task,
+                    trio_side_is_shielded=trio_side_is_shielded,
+                ) as (ctx, first):
+
+                    path_str, cpid = first
+                    tmp_file: Path = Path(path_str)
+                    assert tmp_file.exists()
+
+                    # XXX originally to simulate what (hopefully)
+                    # the below now triggers.. had to manually
+                    # trigger a SIGINT from a ctl-c in the root.
+                    # await trio.sleep_forever()
+
+                    # XXX NOTE XXX signal infected-`asyncio` child to
+                    # OS-cancel with SIGINT; this should trigger the
+                    # bad `asyncio` cancel behaviour that can cause
+                    # a guest-run abandon as was seen causing
+                    # shm-buffer leaks in `piker`'s live quote stream
+                    # susbys!
+                    #
+                    await trio.sleep(.2)
+                    pid: int = (
+                        cpid if send_sigint_to == 'child'
+                        else os.getpid()
+                    )
+                    os.kill(
+                        pid,
+                        signal.SIGINT,
+                    )
+
+                    # XXX CASE 1: without the bug fixed, in
+                    # the non-KBI-raised-in-parent case, this
+                    # timeout should trigger!
+                    if wait_for_ctx:
+                        print('waiting for ctx outcome in parent..')
+                        try:
+                            with trio.fail_after(1):
+                                await ctx.wait_for_result()
+                        except tractor.ContextCancelled as ctxc:
+                            assert ctxc.canceller == ctx.chan.uid
+                            raise
+
+                    # XXX CASE 2: this seems to be the source of the
+                    # original issue which exhibited BEFORE we put
+                    # a `Actor.cancel_soon()` inside
+                    # `run_as_asyncio_guest()`..
+                    else:
+                        raise KeyboardInterrupt
+
+                pytest.fail('should have raised some kinda error?!?')
+
+        except (
+            KeyboardInterrupt,
+            ContextCancelled,
+        ):
+            # XXX CASE 2: without the bug fixed, in the
+            # KBI-raised-in-parent case, the actor teardown should
+            # never get run (silently abaondoned by `asyncio`..) and
+            # thus the file should leak!
+            assert not tmp_file.exists()
+            assert ctx.maybe_error
+
+    trio.run(main)
+
+
 # TODO: debug_mode tests once we get support for `asyncio`!
 #
 # -[ ] need tests to wrap both scripts:

tests/test_local.py

@@ -38,7 +38,7 @@ async def test_self_is_registered_localportal(reg_addr):
     "Verify waiting on the arbiter to register itself using a local portal."
     actor = tractor.current_actor()
     assert actor.is_arbiter
-    async with tractor.get_arbiter(*reg_addr) as portal:
+    async with tractor.get_registry(*reg_addr) as portal:
         assert isinstance(portal, tractor._portal.LocalPortal)
 
         with trio.fail_after(0.2):

tests/test_multi_program.py

@@ -32,7 +32,7 @@ def test_abort_on_sigint(daemon):
 @tractor_test
 async def test_cancel_remote_arbiter(daemon, reg_addr):
     assert not tractor.current_actor().is_arbiter
-    async with tractor.get_arbiter(*reg_addr) as portal:
+    async with tractor.get_registry(*reg_addr) as portal:
         await portal.cancel_actor()
 
     time.sleep(0.1)
@@ -41,7 +41,7 @@ async def test_cancel_remote_arbiter(daemon, reg_addr):
 
     # no arbiter socket should exist
     with pytest.raises(OSError):
-        async with tractor.get_arbiter(*reg_addr) as portal:
+        async with tractor.get_registry(*reg_addr) as portal:
             pass
 
 

tests/test_pldrx_limiting.py

@@ -285,14 +285,14 @@ def test_basic_payload_spec(
 
             if invalid_started:
                 msg_type_str: str = 'Started'
-                bad_value_str: str = '10'
+                bad_value: int = 10
             elif invalid_return:
                 msg_type_str: str = 'Return'
-                bad_value_str: str = "'yo'"
+                bad_value: str = 'yo'
             else:
                 # XXX but should never be used below then..
                 msg_type_str: str = ''
-                bad_value_str: str = ''
+                bad_value: str = ''
 
             maybe_mte: MsgTypeError|None = None
             should_raise: Exception|None = (
@@ -307,8 +307,10 @@ def test_basic_payload_spec(
                     raises=should_raise,
                     ensure_in_message=[
                         f"invalid `{msg_type_str}` msg payload",
-                        f"value: `{bad_value_str}` does not "
-                        f"match type-spec: `{msg_type_str}.pld: PldMsg|NoneType`",
+                        f'{bad_value}',
+                        f'has type {type(bad_value)!r}',
+                        'not match type-spec',
+                        f'`{msg_type_str}.pld: PldMsg|NoneType`',
                     ],
                     # only for debug
                     # post_mortem=True,

tests/test_task_broadcasting.py

@@ -271,7 +271,7 @@ def test_faster_task_to_recv_is_cancelled_by_slower(
                         # the faster subtask was cancelled
                         break
 
-                # await tractor.breakpoint()
+                # await tractor.pause()
                 # await stream.receive()
                 print(f'final value: {value}')
 

tractor/__init__.py

@@ -30,7 +30,7 @@ from ._streaming import (
     stream as stream,
 )
 from ._discovery import (
-    get_arbiter as get_arbiter,
+    get_registry as get_registry,
     find_actor as find_actor,
     wait_for_actor as wait_for_actor,
     query_actor as query_actor,
@@ -49,6 +49,7 @@ from ._exceptions import (
     ModuleNotExposed as ModuleNotExposed,
     MsgTypeError as MsgTypeError,
     RemoteActorError as RemoteActorError,
+    TransportClosed as TransportClosed,
 )
 from .devx import (
     breakpoint as breakpoint,

tractor/_context.py

@@ -38,6 +38,7 @@ from collections import deque
 from contextlib import (
     asynccontextmanager as acm,
 )
+from contextvars import Token
 from dataclasses import (
     dataclass,
     field,
@@ -45,6 +46,7 @@ from dataclasses import (
 from functools import partial
 import inspect
 from pprint import pformat
+import textwrap
 from typing import (
     Any,
     AsyncGenerator,
@@ -121,10 +123,19 @@ class Unresolved:
 @dataclass
 class Context:
     '''
-    An inter-actor, SC transitive, `Task` communication context.
+    An inter-actor, SC transitive, `trio.Task` (pair)
+    communication context.
 
-    NB: This class should **never be instatiated directly**, it is allocated
-    by the runtime in 2 ways:
+    (We've also considered other names and ideas:
+     - "communicating tasks scope": cts
+     - "distributed task scope": dts
+     - "communicating tasks context": ctc
+
+     **Got a better idea for naming? Make an issue dawg!**
+    )
+
+    NB: This class should **never be instatiated directly**, it is
+    allocated by the runtime in 2 ways:
      - by entering `Portal.open_context()` which is the primary
        public API for any "parent" task or,
      - by the RPC machinery's `._rpc._invoke()` as a `ctx` arg
@@ -210,6 +221,16 @@ class Context:
     # more the the `Context` is needed?
     _portal: Portal | None = None
 
+    @property
+    def portal(self) -> Portal|None:
+        '''
+        Return any wrapping memory-`Portal` if this is
+        a 'parent'-side task which called `Portal.open_context()`,
+        otherwise `None`.
+
+        '''
+        return self._portal
+
     # NOTE: each side of the context has its own cancel scope
     # which is exactly the primitive that allows for
     # cross-actor-task-supervision and thus SC.
@@ -299,6 +320,8 @@ class Context:
     # boxed exception. NOW, it's used for spawning overrun queuing
     # tasks when `.allow_overruns ==  True` !!!
     _scope_nursery: trio.Nursery|None = None
+    # ^-TODO-^ change name?
+    # -> `._scope_tn` "scope task nursery"
 
     # streaming overrun state tracking
     _in_overrun: bool = False
@@ -313,6 +336,7 @@ class Context:
         extra_fields: dict[str, Any]|None = None,
         # ^-TODO-^ some built-in extra state fields
         # we'll want in some devx specific cases?
+        indent: str|None = None,
 
     ) -> str:
         ds: str = '='
@@ -332,7 +356,6 @@ class Context:
             show_error_fields=True
         )
         fmtstr: str = (
-            f'<Context(\n'
             # f'\n'
             # f'   ---\n'
             f' |_ipc: {self.dst_maddr}\n'
@@ -379,11 +402,20 @@ class Context:
                     f'   {key}{ds}{val!r}\n'
                 )
 
+        if indent:
+            fmtstr = textwrap.indent(
+                fmtstr,
+                prefix=indent,
+            )
+
         return (
+            '<Context(\n'
+            +
             fmtstr
             +
-            ')>\n'
+            f'{indent})>\n'
         )
+
     # NOTE: making this return a value that can be passed to
     # `eval()` is entirely **optional** dawggg B)
     # https://docs.python.org/3/library/functions.html#repr
@@ -408,10 +440,23 @@ class Context:
         '''
         return self._cancel_called
 
+    @cancel_called.setter
+    def cancel_called(self, val: bool) -> None:
+        '''
+        Set the self-cancelled request `bool` value.
+
+        '''
+        # to debug who frickin sets it..
+        # if val:
+        #     from .devx import pause_from_sync
+        #     pause_from_sync()
+
+        self._cancel_called = val
+
     @property
     def canceller(self) -> tuple[str, str]|None:
         '''
-        ``Actor.uid: tuple[str, str]`` of the (remote)
+        `Actor.uid: tuple[str, str]` of the (remote)
         actor-process who's task was cancelled thus causing this
         (side of the) context to also be cancelled.
 
@@ -515,7 +560,7 @@ class Context:
 
             # the local scope was never cancelled
             # and instead likely we received a remote side
-            # # cancellation that was raised inside `.result()`
+            # # cancellation that was raised inside `.wait_for_result()`
             # or (
             #     (se := self._local_error)
             #     and se is re
@@ -585,6 +630,10 @@ class Context:
         self,
         error: BaseException,
 
+        # TODO: manual toggle for cases where we wouldn't normally
+        # mark ourselves cancelled but want to?
+        # set_cancel_called: bool = False,
+
     ) -> None:
         '''
         (Maybe) cancel this local scope due to a received remote
@@ -603,7 +652,7 @@ class Context:
         - `Portal.open_context()`
         - `Portal.result()`
         - `Context.open_stream()`
-        - `Context.result()`
+        - `Context.wait_for_result()`
 
         when called/closed by actor local task(s).
 
@@ -729,7 +778,7 @@ class Context:
 
         # Cancel the local `._scope`, catch that
         # `._scope.cancelled_caught` and re-raise any remote error
-        # once exiting (or manually calling `.result()`) the
+        # once exiting (or manually calling `.wait_for_result()`) the
         # `.open_context()`  block.
         cs: trio.CancelScope = self._scope
         if (
@@ -764,8 +813,9 @@ class Context:
                 # `trio.Cancelled` subtype here ;)
                 # https://github.com/goodboy/tractor/issues/368
                 message: str = 'Cancelling `Context._scope` !\n\n'
+                # from .devx import pause_from_sync
+                # pause_from_sync()
                 self._scope.cancel()
-
         else:
             message: str = 'NOT cancelling `Context._scope` !\n\n'
             # from .devx import mk_pdb
@@ -845,15 +895,15 @@ class Context:
 
     @property
     def repr_api(self) -> str:
+        return 'Portal.open_context()'
+
+        # TODO: use `.dev._frame_stack` scanning to find caller!
         # ci: CallerInfo|None = self._caller_info
         # if ci:
         #     return (
         #         f'{ci.api_nsp}()\n'
         #     )
 
-        # TODO: use `.dev._frame_stack` scanning to find caller!
-        return 'Portal.open_context()'
-
     async def cancel(
         self,
         timeout: float = 0.616,
@@ -889,14 +939,16 @@ class Context:
 
         '''
         side: str = self.side
-        self._cancel_called: bool = True
+        # XXX for debug via the `@.setter`
+        self.cancel_called = True
 
         header: str = (
-            f'Cancelling ctx with peer from {side.upper()} side\n\n'
+            f'Cancelling ctx from {side.upper()}-side\n'
         )
         reminfo: str = (
             # ' =>\n'
-            f'Context.cancel() => {self.chan.uid}\n'
+            # f'Context.cancel() => {self.chan.uid}\n'
+            f'c)=> {self.chan.uid}\n'
             # f'{self.chan.uid}\n'
             f' |_ @{self.dst_maddr}\n'
             f'    >> {self.repr_rpc}\n'
@@ -912,7 +964,7 @@ class Context:
         # `._scope.cancel()` since we expect the eventual
         # `ContextCancelled` from the other side to trigger this
         # when the runtime finally receives it during teardown
-        # (normally in `.result()` called from
+        # (normally in `.wait_for_result()` called from
         # `Portal.open_context().__aexit__()`)
         if side == 'parent':
             if not self._portal:
@@ -1025,10 +1077,10 @@ class Context:
 
         '''
         __tracebackhide__: bool = hide_tb
-        our_uid: tuple = self.chan.uid
+        peer_uid: tuple = self.chan.uid
 
         # XXX NOTE XXX: `ContextCancelled`/`StreamOverrun` absorption
-        # for "graceful cancellation" case:
+        # for "graceful cancellation" case(s):
         #
         # Whenever a "side" of a context (a `Task` running in
         # an actor) **is** the side which requested ctx
@@ -1045,9 +1097,11 @@ class Context:
         # set to the `Actor.uid` of THIS task (i.e. the
         # cancellation requesting task's actor is the actor
         # checking whether it should absorb the ctxc).
+        self_ctxc: bool = self._is_self_cancelled(remote_error)
         if (
+            self_ctxc
+            and
             not raise_ctxc_from_self_call
-            and self._is_self_cancelled(remote_error)
 
             # TODO: ?potentially it is useful to emit certain
             # warning/cancel logs for the cases where the
@@ -1077,8 +1131,8 @@ class Context:
             and isinstance(remote_error, RemoteActorError)
             and remote_error.boxed_type is StreamOverrun
 
-            # and tuple(remote_error.msgdata['sender']) == our_uid
-            and tuple(remote_error.sender) == our_uid
+            # and tuple(remote_error.msgdata['sender']) == peer_uid
+            and tuple(remote_error.sender) == peer_uid
         ):
             # NOTE: we set the local scope error to any "self
             # cancellation" error-response thus "absorbing"
@@ -1140,9 +1194,9 @@ class Context:
         of the remote cancellation.
 
         '''
-        __tracebackhide__ = hide_tb
+        __tracebackhide__: bool = hide_tb
         assert self._portal, (
-            "Context.result() can not be called from callee side!"
+            '`Context.wait_for_result()` can not be called from callee side!'
         )
         if self._final_result_is_set():
             return self._result
@@ -1197,10 +1251,11 @@ class Context:
                 # raising something we know might happen
                 # during cancellation ;)
                 (not self._cancel_called)
-            )
+            ),
+            hide_tb=hide_tb,
         )
         # TODO: eventually make `.outcome: Outcome` and thus return
-        # `self.outcome.unwrap()` here!
+        # `self.outcome.unwrap()` here?
         return self.outcome
 
     # TODO: switch this with above!
@@ -1223,6 +1278,12 @@ class Context:
 
     @property
     def maybe_error(self) -> BaseException|None:
+        '''
+        Return the (remote) error as outcome or `None`.
+
+        Remote errors take precedence over local ones.
+
+        '''
         le: BaseException|None = self._local_error
         re: RemoteActorError|ContextCancelled|None = self._remote_error
 
@@ -1284,17 +1345,24 @@ class Context:
         Any|
         RemoteActorError|
         ContextCancelled
+        # TODO: make this a `outcome.Outcome`!
     ):
         '''
-        The final "outcome" from an IPC context which can either be
-        some Value returned from the target `@context`-decorated
-        remote task-as-func, or an `Error` wrapping an exception
-        raised from an RPC task fault or cancellation.
+        Return the "final outcome" (state) of the far end peer task
+        non-blocking. If the remote task has not completed then this
+        field always resolves to the module defined `Unresolved`
+        handle.
 
-        Note that if the remote task has not terminated then this
-        field always resolves to the module defined `Unresolved` handle.
+        ------ - ------
+        TODO->( this is doc-driven-dev content not yet actual ;P )
 
-        TODO: implement this using `outcome.Outcome` types?
+        The final "outcome" from an IPC context which can be any of:
+        - some `outcome.Value` which boxes the returned output from the peer task's 
+          `@context`-decorated remote task-as-func, or
+        - an `outcome.Error` wrapping an exception raised that same RPC task
+          after a fault or cancellation, or
+        - an unresolved `outcome.Outcome` when the peer task is still
+          executing and has not yet completed.
 
         '''
         return (
@@ -1583,7 +1651,7 @@ class Context:
 
         - NEVER `return` early before delivering the msg!
           bc if the error is a ctxc and there is a task waiting on
-          `.result()` we need the msg to be
+          `.wait_for_result()` we need the msg to be
           `send_chan.send_nowait()`-ed over the `._rx_chan` so
           that the error is relayed to that waiter task and thus
           raised in user code!
@@ -1635,15 +1703,28 @@ class Context:
         # TODO: expose as mod func instead!
         structfmt = pretty_struct.Struct.pformat
         if self._in_overrun:
-            log.warning(
-                f'Queueing OVERRUN msg on caller task:\n\n'
-
+            report: str = (
                 f'{flow_body}'
-
                 f'{structfmt(msg)}\n'
             )
+            over_q: deque = self._overflow_q
             self._overflow_q.append(msg)
 
+            if len(over_q) == over_q.maxlen:
+                report = (
+                    'FAILED to queue OVERRUN msg, OVERAN the OVERRUN QUEUE !!\n\n'
+                    + report
+                )
+                # log.error(report)
+                log.debug(report)
+
+            else:
+                report = (
+                    'Queueing OVERRUN msg on caller task:\n\n'
+                    + report
+                )
+                log.debug(report)
+
             # XXX NOTE XXX
             # overrun is the ONLY case where returning early is fine!
             return False
@@ -1828,7 +1909,7 @@ async def open_context_from_portal(
     When the "callee" (side that is "called"/started by a call
     to *this* method) returns, the caller side (this) unblocks
     and any final value delivered from the other end can be
-    retrieved using the `Contex.result()` api.
+    retrieved using the `Contex.wait_for_result()` api.
 
     The yielded ``Context`` instance further allows for opening
     bidirectional streams, explicit cancellation and
@@ -1893,7 +1974,7 @@ async def open_context_from_portal(
     )
     assert ctx._remote_func_type == 'context'
     assert ctx._caller_info
-    _ctxvar_Context.set(ctx)
+    prior_ctx_tok: Token = _ctxvar_Context.set(ctx)
 
     # placeholder for any exception raised in the runtime
     # or by user tasks which cause this context's closure.
@@ -1965,14 +2046,14 @@ async def open_context_from_portal(
             yield ctx, first
 
             # ??TODO??: do we still want to consider this or is
-            # the `else:` block handling via a `.result()`
+            # the `else:` block handling via a `.wait_for_result()`
             # call below enough??
             #
-            # -[ ] pretty sure `.result()` internals do the
+            # -[ ] pretty sure `.wait_for_result()` internals do the
             # same as our ctxc handler below so it ended up
             # being same (repeated?) behaviour, but ideally we
             # wouldn't have that duplication either by somehow
-            # factoring the `.result()` handler impl in a way
+            # factoring the `.wait_for_result()` handler impl in a way
             # that we can re-use it around the `yield` ^ here
             # or vice versa?
             #
@@ -2110,7 +2191,7 @@ async def open_context_from_portal(
         #    AND a group-exc is only raised if there was > 1
         #    tasks started *here* in the "caller" / opener
         #    block. If any one of those tasks calls
-        #    `.result()` or `MsgStream.receive()`
+        #    `.wait_for_result()` or `MsgStream.receive()`
         #    `._maybe_raise_remote_err()` will be transitively
         #    called and the remote error raised causing all
         #    tasks to be cancelled.
@@ -2131,9 +2212,16 @@ async def open_context_from_portal(
         # handled in the block above ^^^ !!
         # await _debug.pause()
         # log.cancel(
-        log.exception(
-            f'{ctx.side}-side of `Context` terminated with '
-            f'.outcome => {ctx.repr_outcome()}\n'
+        match scope_err:
+            case trio.Cancelled:
+                logmeth = log.cancel
+
+            # XXX explicitly report on any non-graceful-taskc cases
+            case _:
+                logmeth = log.exception
+
+        logmeth(
+            f'ctx {ctx.side!r}-side exited with {ctx.repr_outcome()}\n'
         )
 
         if debug_mode():
@@ -2180,7 +2268,7 @@ async def open_context_from_portal(
                 f'|_{ctx._task}\n'
             )
             # XXX NOTE XXX: the below call to
-            # `Context.result()` will ALWAYS raise
+            # `Context.wait_for_result()` will ALWAYS raise
             # a `ContextCancelled` (via an embedded call to
             # `Context._maybe_raise_remote_err()`) IFF
             # a `Context._remote_error` was set by the runtime
@@ -2190,10 +2278,10 @@ async def open_context_from_portal(
             # ALWAYS SET any time "callee" side fails and causes "caller
             # side" cancellation via a `ContextCancelled` here.
             try:
-                result_or_err: Exception|Any = await ctx.result()
+                result_or_err: Exception|Any = await ctx.wait_for_result()
             except BaseException as berr:
                 # on normal teardown, if we get some error
-                # raised in `Context.result()` we still want to
+                # raised in `Context.wait_for_result()` we still want to
                 # save that error on the ctx's state to
                 # determine things like `.cancelled_caught` for
                 # cases where there was remote cancellation but
@@ -2311,8 +2399,9 @@ async def open_context_from_portal(
                 and ctx.cancel_acked
             ):
                 log.cancel(
-                    f'Context cancelled by {ctx.side!r}-side task\n'
-                    f'|_{ctx._task}\n\n'
+                    f'Context cancelled by local {ctx.side!r}-side task\n'
+                    f'c)>\n'
+                    f' |_{ctx._task}\n\n'
                     f'{repr(scope_err)}\n'
                 )
 
@@ -2328,8 +2417,10 @@ async def open_context_from_portal(
                     # type_only=True,
                 )
                 log.cancel(
-                    f'Context terminated due to local {ctx.side!r}-side error:\n\n'
-                    f'{ctx.chan.uid} => {outcome_str}\n'
+                    f'Context terminated due to {ctx.side!r}-side\n\n'
+                    # TODO: do an x)> on err and c)> only for ctxc?
+                    f'c)> {outcome_str}\n'
+                    f' |_{ctx.repr_rpc}\n'
                 )
 
         # FINALLY, remove the context from runtime tracking and
@@ -2344,6 +2435,9 @@ async def open_context_from_portal(
             None,
         )
 
+        # XXX revert to prior IPC-task-ctx scope
+        _ctxvar_Context.reset(prior_ctx_tok)
+
 
 def mk_context(
     chan: Channel,

tractor/_discovery.py

@@ -26,8 +26,8 @@ from typing import (
     TYPE_CHECKING,
 )
 from contextlib import asynccontextmanager as acm
-import warnings
 
+from tractor.log import get_logger
 from .trionics import gather_contexts
 from ._ipc import _connect_chan, Channel
 from ._portal import (
@@ -40,11 +40,13 @@ from ._state import (
     _runtime_vars,
 )
 
-
 if TYPE_CHECKING:
     from ._runtime import Actor
 
 
+log = get_logger(__name__)
+
+
 @acm
 async def get_registry(
     host: str,
@@ -56,14 +58,12 @@ async def get_registry(
 ]:
     '''
     Return a portal instance connected to a local or remote
-    arbiter.
+    registry-service actor; if a connection already exists re-use it
+    (presumably to call a `.register_actor()` registry runtime RPC
+    ep).
 
     '''
-    actor = current_actor()
-
-    if not actor:
-        raise RuntimeError("No actor instance has been defined yet?")
-
+    actor: Actor = current_actor()
     if actor.is_registrar:
         # we're already the arbiter
         # (likely a re-entrant call from the arbiter actor)
@@ -72,6 +72,8 @@ async def get_registry(
             Channel((host, port))
         )
     else:
+        # TODO: try to look pre-existing connection from
+        # `Actor._peers` and use it instead?
         async with (
             _connect_chan(host, port) as chan,
             open_portal(chan) as regstr_ptl,
@@ -80,19 +82,6 @@ async def get_registry(
 
 
 
-# TODO: deprecate and this remove _arbiter form!
-@acm
-async def get_arbiter(*args, **kwargs):
-    warnings.warn(
-        '`tractor.get_arbiter()` is now deprecated!\n'
-        'Use `.get_registry()` instead!',
-        DeprecationWarning,
-        stacklevel=2,
-    )
-    async with get_registry(*args, **kwargs) as to_yield:
-        yield to_yield
-
-
 @acm
 async def get_root(
     **kwargs,
@@ -110,22 +99,53 @@ async def get_root(
         yield portal
 
 
+def get_peer_by_name(
+    name: str,
+    # uuid: str|None = None,
+
+) -> list[Channel]|None:  # at least 1
+    '''
+    Scan for an existing connection (set) to a named actor
+    and return any channels from `Actor._peers`.
+
+    This is an optimization method over querying the registrar for
+    the same info.
+
+    '''
+    actor: Actor = current_actor()
+    to_scan: dict[tuple, list[Channel]] = actor._peers.copy()
+    pchan: Channel|None = actor._parent_chan
+    if pchan:
+        to_scan[pchan.uid].append(pchan)
+
+    for aid, chans in to_scan.items():
+        _, peer_name = aid
+        if name == peer_name:
+            if not chans:
+                log.warning(
+                    'No IPC chans for matching peer {peer_name}\n'
+                )
+                continue
+            return chans
+
+    return None
+
+
 @acm
 async def query_actor(
     name: str,
-    arbiter_sockaddr: tuple[str, int] | None = None,
-    regaddr: tuple[str, int] | None = None,
+    regaddr: tuple[str, int]|None = None,
 
 ) -> AsyncGenerator[
-    tuple[str, int] | None,
+    tuple[str, int]|None,
     None,
 ]:
     '''
-    Make a transport address lookup for an actor name to a specific
-    registrar.
+    Lookup a transport address (by actor name) via querying a registrar
+    listening @ `regaddr`.
 
-    Returns the (socket) address or ``None`` if no entry under that
-    name exists for the given registrar listening @ `regaddr`.
+    Returns the transport protocol (socket) address or `None` if no
+    entry under that name exists.
 
     '''
     actor: Actor = current_actor()
@@ -137,14 +157,10 @@ async def query_actor(
             'The current actor IS the registry!?'
         )
 
-    if arbiter_sockaddr is not None:
-        warnings.warn(
-            '`tractor.query_actor(regaddr=<blah>)` is deprecated.\n'
-            'Use `registry_addrs: list[tuple]` instead!',
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        regaddr: list[tuple[str, int]] = arbiter_sockaddr
+    maybe_peers: list[Channel]|None = get_peer_by_name(name)
+    if maybe_peers:
+        yield maybe_peers[0].raddr
+        return
 
     reg_portal: Portal
     regaddr: tuple[str, int] = regaddr or actor.reg_addrs[0]
@@ -159,10 +175,28 @@ async def query_actor(
         yield sockaddr
 
 
+@acm
+async def maybe_open_portal(
+    addr: tuple[str, int],
+    name: str,
+):
+    async with query_actor(
+        name=name,
+        regaddr=addr,
+    ) as sockaddr:
+        pass
+
+    if sockaddr:
+        async with _connect_chan(*sockaddr) as chan:
+            async with open_portal(chan) as portal:
+                yield portal
+    else:
+        yield None
+
+
 @acm
 async def find_actor(
     name: str,
-    arbiter_sockaddr: tuple[str, int]|None = None,
     registry_addrs: list[tuple[str, int]]|None = None,
 
     only_first: bool = True,
@@ -179,29 +213,12 @@ async def find_actor(
     known to the arbiter.
 
     '''
-    if arbiter_sockaddr is not None:
-        warnings.warn(
-            '`tractor.find_actor(arbiter_sockaddr=<blah>)` is deprecated.\n'
-            'Use `registry_addrs: list[tuple]` instead!',
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        registry_addrs: list[tuple[str, int]] = [arbiter_sockaddr]
-
-    @acm
-    async def maybe_open_portal_from_reg_addr(
-        addr: tuple[str, int],
-    ):
-        async with query_actor(
-            name=name,
-            regaddr=addr,
-        ) as sockaddr:
-            if sockaddr:
-                async with _connect_chan(*sockaddr) as chan:
-                    async with open_portal(chan) as portal:
-                        yield portal
-            else:
-                yield None
+    # optimization path, use any pre-existing peer channel
+    maybe_peers: list[Channel]|None = get_peer_by_name(name)
+    if maybe_peers and only_first:
+        async with open_portal(maybe_peers[0]) as peer_portal:
+            yield peer_portal
+            return
 
     if not registry_addrs:
         # XXX NOTE: make sure to dynamically read the value on
@@ -217,10 +234,13 @@ async def find_actor(
     maybe_portals: list[
         AsyncContextManager[tuple[str, int]]
     ] = list(
-        maybe_open_portal_from_reg_addr(addr)
+        maybe_open_portal(
+            addr=addr,
+            name=name,
+        )
         for addr in registry_addrs
     )
-
+    portals: list[Portal]
     async with gather_contexts(
         mngrs=maybe_portals,
     ) as portals:
@@ -254,31 +274,31 @@ async def find_actor(
 @acm
 async def wait_for_actor(
     name: str,
-    arbiter_sockaddr: tuple[str, int] | None = None,
     registry_addr: tuple[str, int] | None = None,
 
 ) -> AsyncGenerator[Portal, None]:
     '''
-    Wait on an actor to register with the arbiter.
-
-    A portal to the first registered actor is returned.
+    Wait on at least one peer actor to register `name` with the
+    registrar, yield a `Portal to the first registree.
 
     '''
     actor: Actor = current_actor()
 
-    if arbiter_sockaddr is not None:
-        warnings.warn(
-            '`tractor.wait_for_actor(arbiter_sockaddr=<foo>)` is deprecated.\n'
-            'Use `registry_addr: tuple` instead!',
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        registry_addr: tuple[str, int] = arbiter_sockaddr
+    # optimization path, use any pre-existing peer channel
+    maybe_peers: list[Channel]|None = get_peer_by_name(name)
+    if maybe_peers:
+        async with open_portal(maybe_peers[0]) as peer_portal:
+            yield peer_portal
+            return
 
+    regaddr: tuple[str, int] = (
+        registry_addr
+        or
+        actor.reg_addrs[0]
+    )
     # TODO: use `.trionics.gather_contexts()` like
     # above in `find_actor()` as well?
     reg_portal: Portal
-    regaddr: tuple[str, int] = registry_addr or actor.reg_addrs[0]
     async with get_registry(*regaddr) as reg_portal:
         sockaddrs = await reg_portal.run_from_ns(
             'self',

tractor/_entry.py

@@ -20,7 +20,9 @@ Sub-process entry points.
 """
 from __future__ import annotations
 from functools import partial
-# import textwrap
+import multiprocessing as mp
+import os
+import textwrap
 from typing import (
     Any,
     TYPE_CHECKING,
@@ -58,25 +60,27 @@ def _mp_main(
 
 ) -> None:
     '''
-    The routine called *after fork* which invokes a fresh ``trio.run``
+    The routine called *after fork* which invokes a fresh `trio.run()`
 
     '''
     actor._forkserver_info = forkserver_info
     from ._spawn import try_set_start_method
-    spawn_ctx = try_set_start_method(start_method)
+    spawn_ctx: mp.context.BaseContext = try_set_start_method(start_method)
+    assert spawn_ctx
 
     if actor.loglevel is not None:
         log.info(
-            f"Setting loglevel for {actor.uid} to {actor.loglevel}")
+            f'Setting loglevel for {actor.uid} to {actor.loglevel}'
+        )
         get_console_log(actor.loglevel)
 
-    assert spawn_ctx
+    # TODO: use scops headers like for `trio` below!
+    # (well after we libify it maybe..)
     log.info(
-        f"Started new {spawn_ctx.current_process()} for {actor.uid}")
-
-    _state._current_actor = actor
-
-    log.debug(f"parent_addr is {parent_addr}")
+        f'Started new {spawn_ctx.current_process()} for {actor.uid}'
+    #     f"parent_addr is {parent_addr}"
+    )
+    _state._current_actor: Actor = actor
     trio_main = partial(
         async_main,
         actor=actor,
@@ -93,7 +97,110 @@ def _mp_main(
         pass  # handle it the same way trio does?
 
     finally:
-        log.info(f"Subactor {actor.uid} terminated")
+        log.info(
+            f'`mp`-subactor {actor.uid} exited'
+        )
+
+
+# TODO: move this func to some kinda `.devx._conc_lang.py` eventually
+# as we work out our multi-domain state-flow-syntax!
+def nest_from_op(
+    input_op: str,
+    #
+    # ?TODO? an idea for a syntax to the state of concurrent systems
+    # as a "3-domain" (execution, scope, storage) model and using
+    # a minimal ascii/utf-8 operator-set.
+    #
+    # try not to take any of this seriously yet XD
+    #
+    # > is a "play operator" indicating (CPU bound)
+    #   exec/work/ops required at the "lowest level computing"
+    #
+    # execution primititves (tasks, threads, actors..) denote their
+    # lifetime with '(' and ')' since parentheses normally are used
+    # in many langs to denote function calls.
+    #
+    # starting = (
+    # >(  opening/starting; beginning of the thread-of-exec (toe?)
+    # (>  opened/started,  (finished spawning toe)
+    # |_<Task: blah blah..>  repr of toe, in py these look like <objs>
+    #
+    # >) closing/exiting/stopping,
+    # )> closed/exited/stopped,
+    # |_<Task: blah blah..>
+    #   [OR <), )< ?? ]
+    #
+    # ending = )
+    # >c) cancelling to close/exit
+    # c)> cancelled (caused close), OR?
+    #  |_<Actor: ..>
+    #   OR maybe "<c)" which better indicates the cancel being
+    #   "delivered/returned" / returned" to LHS?
+    #
+    # >x)  erroring to eventuall exit
+    # x)>  errored and terminated
+    #  |_<Actor: ...>
+    #
+    # scopes: supers/nurseries, IPC-ctxs, sessions, perms, etc.
+    # >{  opening
+    # {>  opened
+    # }>  closed
+    # >}  closing
+    #
+    # storage: like queues, shm-buffers, files, etc..
+    # >[  opening
+    # [>  opened
+    #  |_<FileObj: ..>
+    #
+    # >]  closing
+    # ]>  closed
+
+    # IPC ops: channels, transports, msging
+    # =>  req msg
+    # <=  resp msg
+    # <=> 2-way streaming (of msgs)
+    # <-  recv 1 msg
+    # ->  send 1 msg
+    #
+    # TODO: still not sure on R/L-HS approach..?
+    # =>(  send-req to exec start (task, actor, thread..)
+    # (<=  recv-req to ^
+    #
+    # (<=  recv-req ^
+    # <=(  recv-resp opened remote exec primitive
+    # <=)  recv-resp closed
+    #
+    # )<=c req to stop due to cancel
+    # c=>) req to stop due to cancel
+    #
+    # =>{  recv-req to open
+    # <={  send-status that it closed
+
+    tree_str: str,
+
+    # NOTE: so move back-from-the-left of the `input_op` by
+    # this amount.
+    back_from_op: int = 0,
+) -> str:
+    '''
+    Depth-increment the input (presumably hierarchy/supervision)
+    input "tree string" below the provided `input_op` execution
+    operator, so injecting a `"\n|_{input_op}\n"`and indenting the
+    `tree_str` to nest content aligned with the ops last char.
+
+    '''
+    return (
+        f'{input_op}\n'
+        +
+        textwrap.indent(
+            tree_str,
+            prefix=(
+                len(input_op)
+                -
+                (back_from_op + 1)
+            ) * ' ',
+        )
+    )
 
 
 def _trio_main(
@@ -107,7 +214,6 @@ def _trio_main(
     Entry point for a `trio_run_in_process` subactor.
 
     '''
-    # __tracebackhide__: bool = True
     _debug.hide_runtime_frames()
 
     _state._current_actor = actor
@@ -119,7 +225,6 @@ def _trio_main(
 
     if actor.loglevel is not None:
         get_console_log(actor.loglevel)
-        import os
         actor_info: str = (
             f'|_{actor}\n'
             f'  uid: {actor.uid}\n'
@@ -128,13 +233,24 @@ def _trio_main(
             f'  loglevel: {actor.loglevel}\n'
         )
         log.info(
-            'Started new trio subactor:\n'
+            'Starting new `trio` subactor:\n'
             +
-            '>\n'  # like a "started/play"-icon from super perspective
-            +
-            actor_info,
+            nest_from_op(
+                input_op='>(',  # see syntax ideas above
+                tree_str=actor_info,
+                back_from_op=1,
+            )
+        )
+    logmeth = log.info
+    exit_status: str = (
+        'Subactor exited\n'
+        +
+        nest_from_op(
+            input_op=')>',  # like a "closed-to-play"-icon from super perspective
+            tree_str=actor_info,
+            back_from_op=1,
+        )
     )
-
     try:
         if infect_asyncio:
             actor._infected_aio = True
@@ -143,16 +259,28 @@ def _trio_main(
             trio.run(trio_main)
 
     except KeyboardInterrupt:
-        log.cancel(
-            'Actor received KBI\n'
+        logmeth = log.cancel
+        exit_status: str = (
+            'Actor received KBI (aka an OS-cancel)\n'
             +
-            actor_info
+            nest_from_op(
+                input_op='c)>',  # closed due to cancel (see above)
+                tree_str=actor_info,
             )
+        )
+    except BaseException as err:
+        logmeth = log.error
+        exit_status: str = (
+            'Main actor task exited due to crash?\n'
+            +
+            nest_from_op(
+                input_op='x)>',  # closed by error
+                tree_str=actor_info,
+            )
+        )
+        # NOTE since we raise a tb will already be shown on the
+        # console, thus we do NOT use `.exception()` above.
+        raise err
+
     finally:
-        log.info(
-            'Subactor terminated\n'
-            +
-            'x\n'  # like a "crossed-out/killed" from super perspective
-            +
-            actor_info
-        )
+        logmeth(exit_status)

tractor/_exceptions.py

@@ -609,6 +609,7 @@ class RemoteActorError(Exception):
                 # just after <Type(
                 #             |___ ..
                 tb_body_indent=1,
+                boxer_header=self.relay_uid,
             )
 
         tail = ''
@@ -906,8 +907,59 @@ class StreamOverrun(
     '''
 
 
-class TransportClosed(trio.ClosedResourceError):
-    "Underlying channel transport was closed prior to use"
+class TransportClosed(trio.BrokenResourceError):
+    '''
+    IPC transport (protocol) connection was closed or broke and
+    indicates that the wrapping communication `Channel` can no longer
+    be used to send/receive msgs from the remote peer.
+
+    '''
+    def __init__(
+        self,
+        message: str,
+        loglevel: str = 'transport',
+        cause: BaseException|None = None,
+        raise_on_report: bool = False,
+
+    ) -> None:
+        self.message: str = message
+        self._loglevel = loglevel
+        super().__init__(message)
+
+        if cause is not None:
+            self.__cause__ = cause
+
+        # flag to toggle whether the msg loop should raise
+        # the exc in its `TransportClosed` handler block.
+        self._raise_on_report = raise_on_report
+
+    def report_n_maybe_raise(
+        self,
+        message: str|None = None,
+
+    ) -> None:
+        '''
+        Using the init-specified log level emit a logging report
+        for this error.
+
+        '''
+        message: str = message or self.message
+        # when a cause is set, slap it onto the log emission.
+        if cause := self.__cause__:
+            cause_tb_str: str = ''.join(
+                traceback.format_tb(cause.__traceback__)
+            )
+            message += (
+                f'{cause_tb_str}\n'  # tb
+                f'    {cause}\n'  # exc repr
+            )
+
+        getattr(log, self._loglevel)(message)
+
+        # some errors we want to blow up from
+        # inside the RPC msg loop
+        if self._raise_on_report:
+            raise self from cause
 
 
 class NoResult(RuntimeError):
@@ -922,6 +974,12 @@ class NoRuntime(RuntimeError):
     "The root actor has not been initialized yet"
 
 
+class MessagingError(Exception):
+    '''
+    IPC related msg (typing), transaction (ordering) or dialog
+    handling error.
+
+    '''
 
 class AsyncioCancelled(Exception):
     '''
@@ -929,12 +987,8 @@ class AsyncioCancelled(Exception):
     for use with the ``to_asyncio`` module
     to be raised in the ``trio`` side task
 
-    '''
-
-class MessagingError(Exception):
-    '''
-    IPC related msg (typing), transaction (ordering) or dialog
-    handling error.
+    NOTE: this should NOT inherit from `asyncio.CancelledError` or
+    tests should break!
 
     '''
 
@@ -1324,7 +1378,9 @@ def _mk_recv_mte(
         any_pld: Any = msgpack.decode(msg.pld)
         message: str = (
             f'invalid `{msg_type.__qualname__}` msg payload\n\n'
-            f'value: `{any_pld!r}` does not match type-spec: '
+            f'{any_pld!r}\n\n'
+            f'has type {type(any_pld)!r}\n\n'
+            f'and does not match type-spec '
             f'`{type(msg).__qualname__}.pld: {codec.pld_spec_str}`'
         )
         bad_msg = msg

tractor/_ipc.py

@@ -54,7 +54,7 @@ from tractor._exceptions import (
 )
 from tractor.msg import (
     _ctxvar_MsgCodec,
-    _codec,
+    # _codec,  XXX see `self._codec` sanity/debug checks
     MsgCodec,
     types as msgtypes,
     pretty_struct,
@@ -65,8 +65,18 @@ log = get_logger(__name__)
 _is_windows = platform.system() == 'Windows'
 
 
-def get_stream_addrs(stream: trio.SocketStream) -> tuple:
-    # should both be IP sockets
+def get_stream_addrs(
+    stream: trio.SocketStream
+) -> tuple[
+    tuple[str, int],  # local
+    tuple[str, int],  # remote
+]:
+    '''
+    Return the `trio` streaming transport prot's socket-addrs for
+    both the local and remote sides as a pair.
+
+    '''
+    # rn, should both be IP sockets
     lsockname = stream.socket.getsockname()
     rsockname = stream.socket.getpeername()
     return (
@@ -75,17 +85,22 @@ def get_stream_addrs(stream: trio.SocketStream) -> tuple:
     )
 
 
-# TODO: this should be our `Union[*msgtypes.__spec__]` now right?
-MsgType = TypeVar("MsgType")
-
-# TODO: consider using a generic def and indexing with our eventual
-# msg definition/types?
-# - https://docs.python.org/3/library/typing.html#typing.Protocol
-# - https://jcristharif.com/msgspec/usage.html#structs
+# from tractor.msg.types import MsgType
+# ?TODO? this should be our `Union[*msgtypes.__spec__]` alias now right..?
+# => BLEH, except can't bc prots must inherit typevar or param-spec
+#   vars..
+MsgType = TypeVar('MsgType')
 
 
+# TODO: break up this mod into a subpkg so we can start adding new
+# backends and move this type stuff into a dedicated file.. Bo
+#
 @runtime_checkable
 class MsgTransport(Protocol[MsgType]):
+#
+# ^-TODO-^ consider using a generic def and indexing with our
+# eventual msg definition/types?
+# - https://docs.python.org/3/library/typing.html#typing.Protocol
 
     stream: trio.SocketStream
     drained: list[MsgType]
@@ -120,9 +135,9 @@ class MsgTransport(Protocol[MsgType]):
         ...
 
 
-# TODO: not sure why we have to inherit here, but it seems to be an
-# issue with ``get_msg_transport()`` returning a ``Type[Protocol]``;
-# probably should make a `mypy` issue?
+# TODO: typing oddity.. not sure why we have to inherit here, but it
+# seems to be an issue with `get_msg_transport()` returning
+# a `Type[Protocol]`; probably should make a `mypy` issue?
 class MsgpackTCPStream(MsgTransport):
     '''
     A ``trio.SocketStream`` delivering ``msgpack`` formatted data
@@ -145,7 +160,7 @@ class MsgpackTCPStream(MsgTransport):
         # https://jcristharif.com/msgspec/extending.html#mapping-to-from-native-types
         #
         # TODO: define this as a `Codec` struct which can be
-        # overriden dynamically by the application/runtime.
+        # overriden dynamically by the application/runtime?
         codec: tuple[
             Callable[[Any], Any]|None,  # coder
             Callable[[type, Any], Any]|None,  # decoder
@@ -160,7 +175,7 @@ class MsgpackTCPStream(MsgTransport):
         self._laddr, self._raddr = get_stream_addrs(stream)
 
         # create read loop instance
-        self._agen = self._iter_packets()
+        self._aiter_pkts = self._iter_packets()
         self._send_lock = trio.StrictFIFOLock()
 
         # public i guess?
@@ -174,15 +189,12 @@ class MsgpackTCPStream(MsgTransport):
         # allow for custom IPC msg interchange format
         # dynamic override Bo
         self._task = trio.lowlevel.current_task()
-        self._codec: MsgCodec = (
-            codec
-            or
-            _codec._ctxvar_MsgCodec.get()
-        )
-        # TODO: mask out before release?
-        # log.runtime(
-        #     f'New {self} created with codec\n'
-        #     f'codec: {self._codec}\n'
+
+        # XXX for ctxvar debug only!
+        # self._codec: MsgCodec = (
+        #     codec
+        #     or
+        #     _codec._ctxvar_MsgCodec.get()
         # )
 
     async def _iter_packets(self) -> AsyncGenerator[dict, None]:
@@ -190,6 +202,11 @@ class MsgpackTCPStream(MsgTransport):
         Yield `bytes`-blob decoded packets from the underlying TCP
         stream using the current task's `MsgCodec`.
 
+        This is a streaming routine implemented as an async generator
+        func (which was the original design, but could be changed?)
+        and is allocated by a `.__call__()` inside `.__init__()` where
+        it is assigned to the `._aiter_pkts` attr.
+
         '''
         decodes_failed: int = 0
 
@@ -204,16 +221,82 @@ class MsgpackTCPStream(MsgTransport):
                 # seem to be getting racy failures here on
                 # arbiter/registry name subs..
                 trio.BrokenResourceError,
-            ):
-                raise TransportClosed(
-                    f'transport {self} was already closed prior ro read'
-                )
 
+            ) as trans_err:
+
+                loglevel = 'transport'
+                match trans_err:
+                    # case (
+                    #     ConnectionResetError()
+                    # ):
+                    #     loglevel = 'transport'
+
+                    # peer actor (graceful??) TCP EOF but `tricycle`
+                    # seems to raise a 0-bytes-read?
+                    case ValueError() if (
+                        'unclean EOF' in trans_err.args[0]
+                    ):
+                        pass
+
+                    # peer actor (task) prolly shutdown quickly due
+                    # to cancellation
+                    case trio.BrokenResourceError() if (
+                        'Connection reset by peer' in trans_err.args[0]
+                    ):
+                        pass
+
+                    # unless the disconnect condition falls under "a
+                    # normal operation breakage" we usualy console warn
+                    # about it.
+                    case _:
+                        loglevel: str = 'warning'
+
+
+                raise TransportClosed(
+                    message=(
+                        f'IPC transport already closed by peer\n'
+                        f'x)> {type(trans_err)}\n'
+                        f' |_{self}\n'
+                    ),
+                    loglevel=loglevel,
+                ) from trans_err
+
+            # XXX definitely can happen if transport is closed
+            # manually by another `trio.lowlevel.Task` in the
+            # same actor; we use this in some simulated fault
+            # testing for ex, but generally should never happen
+            # under normal operation!
+            #
+            # NOTE: as such we always re-raise this error from the
+            #       RPC msg loop!
+            except trio.ClosedResourceError as closure_err:
+                raise TransportClosed(
+                    message=(
+                        f'IPC transport already manually closed locally?\n'
+                        f'x)> {type(closure_err)} \n'
+                        f' |_{self}\n'
+                    ),
+                    loglevel='error',
+                    raise_on_report=(
+                        closure_err.args[0] == 'another task closed this fd'
+                        or
+                        closure_err.args[0] in ['another task closed this fd']
+                    ),
+                ) from closure_err
+
+            # graceful TCP EOF disconnect
             if header == b'':
                 raise TransportClosed(
-                    f'transport {self} was already closed prior ro read'
+                    message=(
+                        f'IPC transport already gracefully closed\n'
+                        f')>\n'
+                        f'|_{self}\n'
+                    ),
+                    loglevel='transport',
+                    # cause=???  # handy or no?
                 )
 
+            size: int
             size, = struct.unpack("<I", header)
 
             log.transport(f'received header {size}')  # type: ignore
@@ -225,33 +308,20 @@ class MsgpackTCPStream(MsgTransport):
                 # the current `MsgCodec`.
                 codec: MsgCodec = _ctxvar_MsgCodec.get()
 
-                # TODO: mask out before release?
-                if self._codec.pld_spec != codec.pld_spec:
+                # XXX for ctxvar debug only!
+                # if self._codec.pld_spec != codec.pld_spec:
                 #     assert (
                 #         task := trio.lowlevel.current_task()
                 #     ) is not self._task
                 #     self._task = task
-                    self._codec = codec
-                    log.runtime(
-                        f'Using new codec in {self}.recv()\n'
-                        f'codec: {self._codec}\n\n'
-                        f'msg_bytes: {msg_bytes}\n'
-                    )
+                #     self._codec = codec
+                #     log.runtime(
+                #         f'Using new codec in {self}.recv()\n'
+                #         f'codec: {self._codec}\n\n'
+                #         f'msg_bytes: {msg_bytes}\n'
+                #     )
                 yield codec.decode(msg_bytes)
 
-                # TODO: remove, was only for orig draft impl
-                # testing.
-                #
-                # curr_codec: MsgCodec = _ctxvar_MsgCodec.get()
-                # obj = curr_codec.decode(msg_bytes)
-                # if (
-                #     curr_codec is not
-                #     _codec._def_msgspec_codec
-                # ):
-                #     print(f'OBJ: {obj}\n')
-                #
-                # yield obj
-
             # XXX NOTE: since the below error derives from
             # `DecodeError` we need to catch is specially
             # and always raise such that spec violations
@@ -295,7 +365,8 @@ class MsgpackTCPStream(MsgTransport):
         msg: msgtypes.MsgType,
 
         strict_types: bool = True,
-        # hide_tb: bool = False,
+        hide_tb: bool = False,
+
     ) -> None:
         '''
         Send a msgpack encoded py-object-blob-as-msg over TCP.
@@ -304,21 +375,24 @@ class MsgpackTCPStream(MsgTransport):
         invalid msg type
 
         '''
-        # __tracebackhide__: bool = hide_tb
+        __tracebackhide__: bool = hide_tb
+
+        # XXX see `trio._sync.AsyncContextManagerMixin` for details
+        # on the `.acquire()`/`.release()` sequencing..
         async with self._send_lock:
 
             # NOTE: lookup the `trio.Task.context`'s var for
             # the current `MsgCodec`.
             codec: MsgCodec = _ctxvar_MsgCodec.get()
 
-            # TODO: mask out before release?
-            if self._codec.pld_spec != codec.pld_spec:
-                self._codec = codec
-                log.runtime(
-                    f'Using new codec in {self}.send()\n'
-                    f'codec: {self._codec}\n\n'
-                    f'msg: {msg}\n'
-                )
+            # XXX for ctxvar debug only!
+            # if self._codec.pld_spec != codec.pld_spec:
+            #     self._codec = codec
+            #     log.runtime(
+            #         f'Using new codec in {self}.send()\n'
+            #         f'codec: {self._codec}\n\n'
+            #         f'msg: {msg}\n'
+            #     )
 
             if type(msg) not in msgtypes.__msg_types__:
                 if strict_types:
@@ -352,6 +426,16 @@ class MsgpackTCPStream(MsgTransport):
             size: bytes = struct.pack("<I", len(bytes_data))
             return await self.stream.send_all(size + bytes_data)
 
+        # ?TODO? does it help ever to dynamically show this
+        # frame?
+        # try:
+        #     <the-above_code>
+        # except BaseException as _err:
+        #     err = _err
+        #     if not isinstance(err, MsgTypeError):
+        #         __tracebackhide__: bool = False
+        #     raise
+
     @property
     def laddr(self) -> tuple[str, int]:
         return self._laddr
@@ -361,7 +445,7 @@ class MsgpackTCPStream(MsgTransport):
         return self._raddr
 
     async def recv(self) -> Any:
-        return await self._agen.asend(None)
+        return await self._aiter_pkts.asend(None)
 
     async def drain(self) -> AsyncIterator[dict]:
         '''
@@ -378,7 +462,7 @@ class MsgpackTCPStream(MsgTransport):
                 yield msg
 
     def __aiter__(self):
-        return self._agen
+        return self._aiter_pkts
 
     def connected(self) -> bool:
         return self.stream.socket.fileno() != -1
@@ -433,7 +517,7 @@ class Channel:
         # set after handshake - always uid of far end
         self.uid: tuple[str, str]|None = None
 
-        self._agen = self._aiter_recv()
+        self._aiter_msgs = self._iter_msgs()
         self._exc: Exception|None = None  # set if far end actor errors
         self._closed: bool = False
 
@@ -497,8 +581,6 @@ class Channel:
         )
         return self._transport
 
-    # TODO: something simliar at the IPC-`Context`
-    # level so as to support 
     @cm
     def apply_codec(
         self,
@@ -517,6 +599,7 @@ class Channel:
         finally:
             self._transport.codec = orig
 
+    # TODO: do a .src/.dst: str for maddrs?
     def __repr__(self) -> str:
         if not self._transport:
             return '<Channel with inactive transport?>'
@@ -560,27 +643,43 @@ class Channel:
         )
         return transport
 
+    # TODO: something like,
+    # `pdbp.hideframe_on(errors=[MsgTypeError])`
+    # instead of the `try/except` hack we have rn..
+    # seems like a pretty useful thing to have in general
+    # along with being able to filter certain stack frame(s / sets)
+    # possibly based on the current log-level?
     async def send(
         self,
         payload: Any,
 
-        # hide_tb: bool = False,
+        hide_tb: bool = False,
 
     ) -> None:
         '''
         Send a coded msg-blob over the transport.
 
         '''
-        # __tracebackhide__: bool = hide_tb
+        __tracebackhide__: bool = hide_tb
+        try:
             log.transport(
                 '=> send IPC msg:\n\n'
                 f'{pformat(payload)}\n'
-        )  # type: ignore
-        assert self._transport
+            )
+            # assert self._transport  # but why typing?
             await self._transport.send(
                 payload,
-            # hide_tb=hide_tb,
+                hide_tb=hide_tb,
             )
+        except BaseException as _err:
+            err = _err  # bind for introspection
+            if not isinstance(_err, MsgTypeError):
+                # assert err
+                __tracebackhide__: bool = False
+            else:
+                assert err.cid
+
+            raise
 
     async def recv(self) -> Any:
         assert self._transport
@@ -617,8 +716,11 @@ class Channel:
         await self.aclose(*args)
 
     def __aiter__(self):
-        return self._agen
+        return self._aiter_msgs
 
+    # ?TODO? run any reconnection sequence?
+    # -[ ] prolly should be impl-ed as deco-API?
+    #
     # async def _reconnect(self) -> None:
     #     """Handle connection failures by polling until a reconnect can be
     #     established.
@@ -636,7 +738,6 @@ class Channel:
     #             else:
     #                 log.transport("Stream connection re-established!")
 
-    #                 # TODO: run any reconnection sequence
     #                 # on_recon = self._recon_seq
     #                 # if on_recon:
     #                 #     await on_recon(self)
@@ -650,11 +751,17 @@ class Channel:
     #                     " for re-establishment")
     #             await trio.sleep(1)
 
-    async def _aiter_recv(
+    async def _iter_msgs(
         self
     ) -> AsyncGenerator[Any, None]:
         '''
-        Async iterate items from underlying stream.
+        Yield `MsgType` IPC msgs decoded and deliverd from
+        an underlying `MsgTransport` protocol.
+
+        This is a streaming routine alo implemented as an async-gen
+        func (same a `MsgTransport._iter_pkts()`) gets allocated by
+        a `.__call__()` inside `.__init__()` where it is assigned to
+        the `._aiter_msgs` attr.
 
         '''
         assert self._transport
@@ -680,15 +787,6 @@ class Channel:
                         case _:
                             yield msg
 
-                    # TODO: if we were gonna do this it should be
-                    # done up at the `MsgStream` layer!
-                    #
-                    # sent = yield item
-                    # if sent is not None:
-                    #     # optimization, passing None through all the
-                    #     # time is pointless
-                    #     await self._transport.send(sent)
-
             except trio.BrokenResourceError:
 
                 # if not self._autorecon:

tractor/_portal.py

@@ -97,7 +97,7 @@ class Portal:
         channel: Channel,
     ) -> None:
 
-        self.chan = channel
+        self._chan: Channel = channel
         # during the portal's lifetime
         self._final_result_pld: Any|None = None
         self._final_result_msg: PayloadMsg|None = None
@@ -109,6 +109,10 @@ class Portal:
         self._streams: set[MsgStream] = set()
         self.actor: Actor = current_actor()
 
+    @property
+    def chan(self) -> Channel:
+        return self._chan
+
     @property
     def channel(self) -> Channel:
         '''
@@ -121,7 +125,8 @@ class Portal:
         )
         return self.chan
 
-    # TODO: factor this out into an `ActorNursery` wrapper
+    # TODO: factor this out into a `.highlevel` API-wrapper that uses
+    # a single `.open_context()` call underneath.
     async def _submit_for_result(
         self,
         ns: str,
@@ -141,13 +146,22 @@ class Portal:
             portal=self,
         )
 
+    # TODO: we should deprecate this API right? since if we remove
+    # `.run_in_actor()` (and instead move it to a `.highlevel`
+    # wrapper api (around a single `.open_context()` call) we don't
+    # really have any notion of a "main" remote task any more?
+    #
     # @api_frame
-    async def result(self) -> Any:
+    async def wait_for_result(
+        self,
+        hide_tb: bool = True,
+    ) -> Any:
         '''
-        Return the result(s) from the remote actor's "main" task.
+        Return the final result delivered by a `Return`-msg from the
+        remote peer actor's "main" task's `return` statement.
 
         '''
-        __tracebackhide__ = True
+        __tracebackhide__: bool = hide_tb
         # Check for non-rpc errors slapped on the
         # channel for which we always raise
         exc = self.channel._exc
@@ -182,6 +196,23 @@ class Portal:
 
         return self._final_result_pld
 
+    # TODO: factor this out into a `.highlevel` API-wrapper that uses
+    # a single `.open_context()` call underneath.
+    async def result(
+        self,
+        *args,
+        **kwargs,
+    ) -> Any|Exception:
+        typname: str = type(self).__name__
+        log.warning(
+            f'`{typname}.result()` is DEPRECATED!\n'
+            f'Use `{typname}.wait_for_result()` instead!\n'
+        )
+        return await self.wait_for_result(
+            *args,
+            **kwargs,
+        )
+
     async def _cancel_streams(self):
         # terminate all locally running async generator
         # IPC calls
@@ -232,14 +263,15 @@ class Portal:
             return False
 
         reminfo: str = (
-            f'Portal.cancel_actor() => {self.channel.uid}\n'
-            f'|_{chan}\n'
+            f'c)=> {self.channel.uid}\n'
+            f'  |_{chan}\n'
         )
         log.cancel(
-            f'Requesting runtime cancel for peer\n\n'
+            f'Requesting actor-runtime cancel for peer\n\n'
             f'{reminfo}'
         )
 
+        # XXX the one spot we set it?
         self.channel._cancel_called: bool = True
         try:
             # send cancel cmd - might not get response
@@ -279,6 +311,8 @@ class Portal:
             )
             return False
 
+    # TODO: do we still need this for low level `Actor`-runtime
+    # method calls or can we also remove it?
     async def run_from_ns(
         self,
         namespace_path: str,
@@ -316,6 +350,8 @@ class Portal:
             expect_msg=Return,
         )
 
+    # TODO: factor this out into a `.highlevel` API-wrapper that uses
+    # a single `.open_context()` call underneath.
     async def run(
         self,
         func: str,
@@ -370,6 +406,8 @@ class Portal:
             expect_msg=Return,
         )
 
+    # TODO: factor this out into a `.highlevel` API-wrapper that uses
+    # a single `.open_context()` call underneath.
     @acm
     async def open_stream_from(
         self,

tractor/_root.py

@@ -21,6 +21,7 @@ Root actor runtime ignition(s).
 from contextlib import asynccontextmanager as acm
 from functools import partial
 import importlib
+import inspect
 import logging
 import os
 import signal
@@ -79,7 +80,7 @@ async def open_root_actor(
 
     # enables the multi-process debugger support
     debug_mode: bool = False,
-    maybe_enable_greenback: bool = False,  # `.pause_from_sync()/breakpoint()` support
+    maybe_enable_greenback: bool = True,  # `.pause_from_sync()/breakpoint()` support
     enable_stack_on_sig: bool = False,
 
     # internal logging
@@ -94,6 +95,10 @@ async def open_root_actor(
 
     hide_tb: bool = True,
 
+    # TODO, a way for actors to augment passing derived
+    # read-only state to sublayers?
+    # extra_rt_vars: dict|None = None,
+
 ) -> Actor:
     '''
     Runtime init entry point for ``tractor``.
@@ -115,10 +120,16 @@ async def open_root_actor(
     if (
         debug_mode
         and maybe_enable_greenback
-        and await _debug.maybe_init_greenback(
+        and (
+            maybe_mod := await _debug.maybe_init_greenback(
                 raise_not_found=False,
             )
+        )
     ):
+        logger.info(
+            f'Found `greenback` installed @ {maybe_mod}\n'
+            'Enabling `tractor.pause_from_sync()` support!\n'
+        )
         os.environ['PYTHONBREAKPOINT'] = (
             'tractor.devx._debug._sync_pause_from_builtin'
         )
@@ -226,14 +237,8 @@ async def open_root_actor(
         and
         enable_stack_on_sig
     ):
-        try:
-            logger.info('Enabling `stackscope` traces on SIGUSR1')
-            from .devx import enable_stack_on_sig
+        from .devx._stackscope import enable_stack_on_sig
         enable_stack_on_sig()
-        except ImportError:
-            logger.warning(
-                '`stackscope` not installed for use in debug mode!'
-            )
 
     # closed into below ping task-func
     ponged_addrs: list[tuple[str, int]] = []
@@ -264,7 +269,9 @@ async def open_root_actor(
 
         except OSError:
             # TODO: make this a "discovery" log level?
-            logger.warning(f'No actor registry found @ {addr}')
+            logger.info(
+                f'No actor registry found @ {addr}\n'
+            )
 
     async with trio.open_nursery() as tn:
         for addr in registry_addrs:
@@ -278,7 +285,6 @@ async def open_root_actor(
     # Create a new local root-actor instance which IS NOT THE
     # REGISTRAR
     if ponged_addrs:
-
         if ensure_registry:
             raise RuntimeError(
                  f'Failed to open `{name}`@{ponged_addrs}: '
@@ -365,23 +371,25 @@ async def open_root_actor(
             )
             try:
                 yield actor
-
             except (
                 Exception,
                 BaseExceptionGroup,
             ) as err:
-
-                import inspect
+                # XXX NOTE XXX see equiv note inside
+                # `._runtime.Actor._stream_handler()` where in the
+                # non-root or root-that-opened-this-mahually case we
+                # wait for the local actor-nursery to exit before
+                # exiting the transport channel handler.
                 entered: bool = await _debug._maybe_enter_pm(
                     err,
                     api_frame=inspect.currentframe(),
                 )
-
                 if (
                     not entered
-                    and not is_multi_cancelled(err)
+                    and
+                    not is_multi_cancelled(err)
                 ):
-                    logger.exception('Root actor crashed:\n')
+                    logger.exception('Root actor crashed\n')
 
                 # ALWAYS re-raise any error bubbled up from the
                 # runtime!

tractor/_rpc.py

@@ -68,7 +68,7 @@ from .msg import (
     MsgCodec,
     PayloadT,
     NamespacePath,
-    pretty_struct,
+    # pretty_struct,
     _ops as msgops,
 )
 from tractor.msg.types import (
@@ -89,6 +89,16 @@ if TYPE_CHECKING:
 log = get_logger('tractor')
 
 
+# ?TODO? move to a `tractor.lowlevel._rpc` with the below
+# func-type-cases implemented "on top of" `@context` defs:
+# -[ ] std async func helper decorated with `@rpc_func`?
+# -[ ] `Portal.open_stream_from()` with async-gens?
+#  |_ possibly a duplex form of this with a
+#    `sent_from_peer = yield send_to_peer` form, which would require
+#    syncing the send/recv side with possibly `.receive_nowait()`
+#    on each `yield`?
+# -[ ] some kinda `@rpc_acm` maybe that does a fixture style with
+#     user only defining a single-`yield` generator-func?
 async def _invoke_non_context(
     actor: Actor,
     cancel_scope: CancelScope,
@@ -108,8 +118,9 @@ async def _invoke_non_context(
     ] = trio.TASK_STATUS_IGNORED,
 ):
     __tracebackhide__: bool = True
+    cs: CancelScope|None = None  # ref when activated
 
-    # TODO: can we unify this with the `context=True` impl below?
+    # ?TODO? can we unify this with the `context=True` impl below?
     if inspect.isasyncgen(coro):
         await chan.send(
             StartAck(
@@ -160,10 +171,6 @@ async def _invoke_non_context(
                 functype='asyncgen',
             )
         )
-        # XXX: the async-func may spawn further tasks which push
-        # back values like an async-generator would but must
-        # manualy construct the response dict-packet-responses as
-        # above
         with cancel_scope as cs:
             ctx._scope = cs
             task_status.started(ctx)
@@ -175,15 +182,13 @@ async def _invoke_non_context(
             await chan.send(
                 Stop(cid=cid)
             )
-    else:
-        # regular async function/method
-        # XXX: possibly just a scheduled `Actor._cancel_task()`
-        # from a remote request to cancel some `Context`.
+
+    # simplest function/method request-response pattern
+    # XXX: in the most minimally used case, just a scheduled internal runtime
+    # call to `Actor._cancel_task()` from the ctx-peer task since we
+    # don't (yet) have a dedicated IPC msg.
     # ------ - ------
-        # TODO: ideally we unify this with the above `context=True`
-        # block such that for any remote invocation ftype, we
-        # always invoke the far end RPC task scheduling the same
-        # way: using the linked IPC context machinery.
+    else:
         failed_resp: bool = False
         try:
             ack = StartAck(
@@ -354,8 +359,15 @@ async def _errors_relayed_via_ipc(
             # channel.
             task_status.started(err)
 
-        # always reraise KBIs so they propagate at the sys-process level.
-        if isinstance(err, KeyboardInterrupt):
+        # always propagate KBIs at the sys-process level.
+        if (
+            isinstance(err, KeyboardInterrupt)
+
+            # ?TODO? except when running in asyncio mode?
+            # |_ wut if you want to open a `@context` FROM an
+            # infected_aio task?
+            # and not actor.is_infected_aio()
+        ):
             raise
 
     # RPC task bookeeping.
@@ -458,7 +470,6 @@ async def _invoke(
     # tb: TracebackType = None
 
     cancel_scope = CancelScope()
-    cs: CancelScope|None = None  # ref when activated
     ctx = actor.get_context(
         chan=chan,
         cid=cid,
@@ -607,6 +618,8 @@ async def _invoke(
         #     `@context` marked RPC function.
         # - `._portal` is never set.
         try:
+            tn: trio.Nursery
+            rpc_ctx_cs: CancelScope
             async with (
                 trio.open_nursery() as tn,
                 msgops.maybe_limit_plds(
@@ -616,7 +629,7 @@ async def _invoke(
                 ),
             ):
                 ctx._scope_nursery = tn
-                ctx._scope = tn.cancel_scope
+                rpc_ctx_cs = ctx._scope = tn.cancel_scope
                 task_status.started(ctx)
 
                 # TODO: better `trionics` tooling:
@@ -642,7 +655,7 @@ async def _invoke(
             #   itself calls `ctx._maybe_cancel_and_set_remote_error()`
             #   which cancels the scope presuming the input error
             #   is not a `.cancel_acked` pleaser.
-            if ctx._scope.cancelled_caught:
+            if rpc_ctx_cs.cancelled_caught:
                 our_uid: tuple = actor.uid
 
                 # first check for and raise any remote error
@@ -652,9 +665,7 @@ async def _invoke(
                 if re := ctx._remote_error:
                     ctx._maybe_raise_remote_err(re)
 
-                cs: CancelScope = ctx._scope
-
-                if cs.cancel_called:
+                if rpc_ctx_cs.cancel_called:
                     canceller: tuple = ctx.canceller
                     explain: str = f'{ctx.side!r}-side task was cancelled by '
 
@@ -680,9 +691,15 @@ async def _invoke(
                     elif canceller == ctx.chan.uid:
                         explain += f'its {ctx.peer_side!r}-side peer'
 
-                    else:
+                    elif canceller == our_uid:
+                        explain += 'itself'
+
+                    elif canceller:
                         explain += 'a remote peer'
 
+                    else:
+                        explain += 'an unknown cause?'
+
                     explain += (
                         add_div(message=explain)
                         +
@@ -911,7 +928,10 @@ async def process_messages(
                     f'IPC msg from peer\n'
                     f'<= {chan.uid}\n\n'
 
-                    # TODO: avoid fmting depending on loglevel for perf?
+                    # TODO: use of the pprinting of structs is
+                    # FRAGILE and should prolly not be
+                    #
+                    # avoid fmting depending on loglevel for perf?
                     # -[ ] specifically `pretty_struct.pformat()` sub-call..?
                     #   - how to only log-level-aware actually call this?
                     # -[ ] use `.msg.pretty_struct` here now instead!
@@ -1177,7 +1197,7 @@ async def process_messages(
                 parent_chan=chan,
             )
 
-    except TransportClosed:
+    except TransportClosed as tc:
         # channels "breaking" (for TCP streams by EOF or 104
         # connection-reset) is ok since we don't have a teardown
         # handshake for them (yet) and instead we simply bail out of
@@ -1185,12 +1205,20 @@ async def process_messages(
         # up..
         #
         # TODO: maybe add a teardown handshake? and,
-        # -[ ] don't show this msg if it's an ephemeral discovery ep call?
+        # -[x] don't show this msg if it's an ephemeral discovery ep call?
+        #  |_ see the below `.report_n_maybe_raise()` impl as well as
+        #     tc-exc input details in `MsgpackTCPStream._iter_pkts()`
+        #     for different read-failure cases.
         # -[ ] figure out how this will break with other transports?
-        log.runtime(
-            f'IPC channel closed abruptly\n'
-            f'<=x peer: {chan.uid}\n'
-            f'   |_{chan.raddr}\n'
+        tc.report_n_maybe_raise(
+            message=(
+                f'peer IPC channel closed abruptly?\n\n'
+                f'<=x {chan}\n'
+                f'  |_{chan.raddr}\n\n'
+            )
+            +
+            tc.message
+
         )
 
         # transport **WAS** disconnected
@@ -1238,7 +1266,7 @@ async def process_messages(
                 'Exiting IPC msg loop with final msg\n\n'
                 f'<= peer: {chan.uid}\n'
                 f'  |_{chan}\n\n'
-                f'{pretty_struct.pformat(msg)}'
+                # f'{pretty_struct.pformat(msg)}'
             )
 
         log.runtime(message)

tractor/_runtime.py

@@ -59,6 +59,7 @@ import os
 import warnings
 
 import trio
+from trio._core import _run as trio_runtime
 from trio import (
     CancelScope,
     Nursery,
@@ -66,10 +67,11 @@ from trio import (
 )
 
 from tractor.msg import (
-    pretty_struct,
-    NamespacePath,
-    types as msgtypes,
     MsgType,
+    NamespacePath,
+    Stop,
+    pretty_struct,
+    types as msgtypes,
 )
 from ._ipc import Channel
 from ._context import (
@@ -79,6 +81,7 @@ from ._context import (
 from .log import get_logger
 from ._exceptions import (
     ContextCancelled,
+    InternalError,
     ModuleNotExposed,
     MsgTypeError,
     unpack_error,
@@ -101,6 +104,7 @@ from ._rpc import (
 
 if TYPE_CHECKING:
     from ._supervise import ActorNursery
+    from trio._channel import MemoryChannelState
 
 
 log = get_logger('tractor')
@@ -114,25 +118,26 @@ class Actor:
     '''
     The fundamental "runtime" concurrency primitive.
 
-    An *actor* is the combination of a regular Python process executing
-    a ``trio`` task tree, communicating with other actors through
-    "memory boundary portals" - which provide a native async API around
-    IPC transport "channels" which themselves encapsulate various
-    (swappable) network protocols.
+    An "actor" is the combination of a regular Python process
+    executing a `trio.run()` task tree, communicating with other
+    "actors" through "memory boundary portals": `Portal`, which
+    provide a high-level async API around IPC "channels" (`Channel`)
+    which themselves encapsulate various (swappable) network
+    transport protocols for sending msgs between said memory domains
+    (processes, hosts, non-GIL threads).
 
-
-    Each "actor" is ``trio.run()`` scheduled "runtime" composed of
-    many concurrent tasks in a single thread. The "runtime" tasks
-    conduct a slew of low(er) level functions to make it possible
-    for message passing between actors as well as the ability to
-    create new actors (aka new "runtimes" in new processes which
-    are supervised via a nursery construct). Each task which sends
-    messages to a task in a "peer" (not necessarily a parent-child,
+    Each "actor" is `trio.run()` scheduled "runtime" composed of many
+    concurrent tasks in a single thread. The "runtime" tasks conduct
+    a slew of low(er) level functions to make it possible for message
+    passing between actors as well as the ability to create new
+    actors (aka new "runtimes" in new processes which are supervised
+    via an "actor-nursery" construct). Each task which sends messages
+    to a task in a "peer" actor (not necessarily a parent-child,
     depth hierarchy) is able to do so via an "address", which maps
     IPC connections across memory boundaries, and a task request id
-    which allows for per-actor tasks to send and receive messages
-    to specific peer-actor tasks with which there is an ongoing
-    RPC/IPC dialog.
+    which allows for per-actor tasks to send and receive messages to
+    specific peer-actor tasks with which there is an ongoing RPC/IPC
+    dialog.
 
     '''
     # ugh, we need to get rid of this and replace with a "registry" sys
@@ -229,17 +234,20 @@ class Actor:
         # by the user (currently called the "arbiter")
         self._spawn_method: str = spawn_method
 
-        self._peers: defaultdict = defaultdict(list)
+        self._peers: defaultdict[
+            str,  # uaid
+            list[Channel],  # IPC conns from peer
+        ] = defaultdict(list)
         self._peer_connected: dict[tuple[str, str], trio.Event] = {}
         self._no_more_peers = trio.Event()
         self._no_more_peers.set()
+
+        # RPC state
         self._ongoing_rpc_tasks = trio.Event()
         self._ongoing_rpc_tasks.set()
-
-        # (chan, cid) -> (cancel_scope, func)
         self._rpc_tasks: dict[
-            tuple[Channel, str],
-            tuple[Context, Callable, trio.Event]
+            tuple[Channel, str],  # (chan, cid)
+            tuple[Context, Callable, trio.Event]  # (ctx=>, fn(), done?)
         ] = {}
 
         # map {actor uids -> Context}
@@ -316,7 +324,10 @@ class Actor:
         event = self._peer_connected.setdefault(uid, trio.Event())
         await event.wait()
         log.debug(f'{uid!r} successfully connected back to us')
-        return event, self._peers[uid][-1]
+        return (
+            event,
+            self._peers[uid][-1],
+        )
 
     def load_modules(
         self,
@@ -407,26 +418,11 @@ class Actor:
         '''
         self._no_more_peers = trio.Event()  # unset by making new
         chan = Channel.from_stream(stream)
-        their_uid: tuple[str, str]|None = chan.uid
-
-        con_status: str = ''
-
-        # TODO: remove this branch since can never happen?
-        # NOTE: `.uid` is only set after first contact
-        if their_uid:
-            con_status = (
-                'IPC Re-connection from already known peer?\n'
-            )
-        else:
-            con_status = (
+        con_status: str = (
             'New inbound IPC connection <=\n'
+            f'|_{chan}\n'
         )
 
-        con_status += (
-            f'|_{chan}\n'
-            # f' |_@{chan.raddr}\n\n'
-            # ^-TODO-^ remove since alfready in chan.__repr__()?
-        )
         # send/receive initial handshake response
         try:
             uid: tuple|None = await self._do_handshake(chan)
@@ -438,10 +434,10 @@ class Actor:
 
             TransportClosed,
         ):
-            # XXX: This may propagate up from ``Channel._aiter_recv()``
-            # and ``MsgpackStream._inter_packets()`` on a read from the
+            # XXX: This may propagate up from `Channel._aiter_recv()`
+            # and `MsgpackStream._inter_packets()` on a read from the
             # stream particularly when the runtime is first starting up
-            # inside ``open_root_actor()`` where there is a check for
+            # inside `open_root_actor()` where there is a check for
             # a bound listener on the "arbiter" addr.  the reset will be
             # because the handshake was never meant took place.
             log.runtime(
@@ -451,9 +447,25 @@ class Actor:
             )
             return
 
+        familiar: str = 'new-peer'
+        if _pre_chan := self._peers.get(uid):
+            familiar: str = 'pre-existing-peer'
+        uid_short: str = f'{uid[0]}[{uid[1][-6:]}]'
         con_status += (
-            f' -> Handshake with actor `{uid[0]}[{uid[1][-6:]}]` complete\n'
+            f' -> Handshake with {familiar} `{uid_short}` complete\n'
         )
+
+        if _pre_chan:
+            # con_status += (
+            # ^TODO^ swap once we minimize conn duplication
+            # -[ ] last thing might be reg/unreg runtime reqs?
+            # log.warning(
+            log.debug(
+                f'?Wait?\n'
+                f'We already have IPC with peer {uid_short!r}\n'
+                f'|_{_pre_chan}\n'
+            )
+
         # IPC connection tracking for both peers and new children:
         # - if this is a new channel to a locally spawned
         #   sub-actor there will be a spawn wait even registered
@@ -506,8 +518,9 @@ class Actor:
             )
         except trio.Cancelled:
             log.cancel(
-                'IPC transport msg loop was cancelled for \n'
-                f'|_{chan}\n'
+                'IPC transport msg loop was cancelled\n'
+                f'c)>\n'
+                f' |_{chan}\n'
             )
             raise
 
@@ -544,8 +557,9 @@ class Actor:
 
             ):
                 log.cancel(
-                    'Waiting on cancel request to peer\n'
-                    f'`Portal.cancel_actor()` => {chan.uid}\n'
+                    'Waiting on cancel request to peer..\n'
+                    f'c)=>\n'
+                    f'  |_{chan.uid}\n'
                 )
 
                 # XXX: this is a soft wait on the channel (and its
@@ -642,12 +656,18 @@ class Actor:
                         # and
                         an_exit_cs.cancelled_caught
                     ):
-                        log.warning(
+                        report: str = (
                             'Timed out waiting on local actor-nursery to exit?\n'
-                            f'{local_nursery}\n'
-                            f' |_{pformat(local_nursery._children)}\n'
+                            f'c)>\n'
+                            f' |_{local_nursery}\n'
                         )
-                        # await _debug.pause()
+                        if children := local_nursery._children:
+                            # indent from above local-nurse repr
+                            report += (
+                                f'   |_{pformat(children)}\n'
+                            )
+
+                        log.warning(report)
 
                 if disconnected:
                     # if the transport died and this actor is still
@@ -819,14 +839,17 @@ class Actor:
                 # side,
             )]
         except KeyError:
-            log.warning(
+            report: str = (
                 'Ignoring invalid IPC ctx msg!\n\n'
-                f'<= sender: {uid}\n\n'
-                # XXX don't need right since it's always in msg?
-                # f'=> cid: {cid}\n\n'
-
-                f'{pretty_struct.pformat(msg)}\n'
+                f'<=? {uid}\n\n'
+                f'  |_{pretty_struct.pformat(msg)}\n'
             )
+            match msg:
+                case Stop():
+                    log.runtime(report)
+                case _:
+                    log.warning(report)
+
             return
 
         # if isinstance(msg, MsgTypeError):
@@ -880,11 +903,15 @@ class Actor:
                 f'peer: {chan.uid}\n'
                 f'cid:{cid}\n'
             )
-            ctx._allow_overruns = allow_overruns
+            ctx._allow_overruns: bool = allow_overruns
 
             # adjust buffer size if specified
-            state = ctx._send_chan._state  # type: ignore
-            if msg_buffer_size and state.max_buffer_size != msg_buffer_size:
+            state: MemoryChannelState  = ctx._send_chan._state  # type: ignore
+            if (
+                msg_buffer_size
+                and
+                state.max_buffer_size != msg_buffer_size
+            ):
                 state.max_buffer_size = msg_buffer_size
 
         except KeyError:
@@ -1046,6 +1073,10 @@ class Actor:
                 # TODO: another `Struct` for rtvs..
                 rvs: dict[str, Any] = spawnspec._runtime_vars
                 if rvs['_debug_mode']:
+                    from .devx import (
+                        enable_stack_on_sig,
+                        maybe_init_greenback,
+                    )
                     try:
                         # TODO: maybe return some status msgs upward
                         # to that we can emit them in `con_status`
@@ -1053,14 +1084,57 @@ class Actor:
                         log.devx(
                             'Enabling `stackscope` traces on SIGUSR1'
                         )
-                        from .devx import enable_stack_on_sig
                         enable_stack_on_sig()
+
                     except ImportError:
                         log.warning(
                             '`stackscope` not installed for use in debug mode!'
                         )
 
-                rvs['_is_root'] = False
+                    if rvs.get('use_greenback', False):
+                        maybe_mod: ModuleType|None = await maybe_init_greenback()
+                        if maybe_mod:
+                            log.devx(
+                                'Activated `greenback` '
+                                'for `tractor.pause_from_sync()` support!'
+                            )
+                        else:
+                            rvs['use_greenback'] = False
+                            log.warning(
+                                '`greenback` not installed for use in debug mode!\n'
+                                '`tractor.pause_from_sync()` not available!'
+                            )
+
+                # XXX ensure the "infected `asyncio` mode" setting
+                # passed down from our spawning parent is consistent
+                # with `trio`-runtime initialization:
+                # - during sub-proc boot, the entrypoint func
+                #   (`._entry.<spawn_backend>_main()`) should set
+                #   `._infected_aio = True` before calling
+                #   `run_as_asyncio_guest()`,
+                # - the value of `infect_asyncio: bool = True` as
+                #   passed to `ActorNursery.start_actor()` must be
+                #   the same as `_runtime_vars['_is_infected_aio']`
+                if (
+                    (aio_rtv := rvs['_is_infected_aio'])
+                    !=
+                    (aio_attr := self._infected_aio)
+                ):
+                    raise InternalError(
+                        'Parent sent runtime-vars that mismatch for the '
+                        '"infected `asyncio` mode" settings ?!?\n\n'
+
+                        f'rvs["_is_infected_aio"] = {aio_rtv}\n'
+                        f'self._infected_aio = {aio_attr}\n'
+                    )
+                if aio_rtv:
+                    assert trio_runtime.GLOBAL_RUN_CONTEXT.runner.is_guest
+                    # ^TODO^ possibly add a `sniffio` or
+                    # `trio` pub-API for `is_guest_mode()`?
+
+                rvs['_is_root'] = False  # obvi XD
+
+                # update process-wide globals
                 _state._runtime_vars.update(rvs)
 
                 # XXX: ``msgspec`` doesn't support serializing tuples
@@ -1211,8 +1285,9 @@ class Actor:
         # TODO: just use the new `Context.repr_rpc: str` (and
         # other) repr fields instead of doing this all manual..
         msg: str = (
-            f'Runtime cancel request from {requester_type}:\n\n'
-            f'<= .cancel(): {requesting_uid}\n\n'
+            f'Actor-runtime cancel request from {requester_type}\n\n'
+            f'<=c) {requesting_uid}\n'
+            f' |_{self}\n'
         )
 
         # TODO: what happens here when we self-cancel tho?
@@ -1320,10 +1395,11 @@ class Actor:
             return True
 
         log.cancel(
-            'Cancel request for RPC task\n\n'
-            f'<= Actor._cancel_task(): {requesting_uid}\n\n'
-            f'=> {ctx._task}\n'
-            f'  |_ >> {ctx.repr_rpc}\n'
+            'Rxed cancel request for RPC task\n'
+            f'<=c) {requesting_uid}\n'
+            f' |_{ctx._task}\n'
+            f'    >> {ctx.repr_rpc}\n'
+            # f'=> {ctx._task}\n'
             # f'  >> Actor._cancel_task() => {ctx._task}\n'
             # f'  |_ {ctx._task}\n\n'
 
@@ -1445,11 +1521,11 @@ class Actor:
         )
         log.cancel(
             f'Cancelling {descr} RPC tasks\n\n'
-            f'<= canceller: {req_uid}\n'
+            f'<=c) {req_uid} [canceller]\n'
             f'{rent_chan_repr}'
-            f'=> cancellee: {self.uid}\n'
-            f'  |_{self}.cancel_rpc_tasks()\n'
-            f'  |_tasks: {len(tasks)}\n'
+            f'c)=> {self.uid} [cancellee]\n'
+            f'  |_{self} [with {len(tasks)} tasks]\n'
+            # f'  |_tasks: {len(tasks)}\n'
             # f'{tasks_str}'
         )
         for (
@@ -1518,7 +1594,7 @@ class Actor:
     def accept_addr(self) -> tuple[str, int]:
         '''
         Primary address to which the IPC transport server is
-        bound.
+        bound and listening for new connections.
 
         '''
         # throws OSError on failure
@@ -1535,6 +1611,7 @@ class Actor:
     def get_chans(
         self,
         uid: tuple[str, str],
+
     ) -> list[Channel]:
         '''
         Return all IPC channels to the actor with provided `uid`.
@@ -1717,8 +1794,8 @@ async def async_main(
 
                 # Register with the arbiter if we're told its addr
                 log.runtime(
-                    f'Registering `{actor.name}` ->\n'
-                    f'{pformat(accept_addrs)}'
+                    f'Registering `{actor.name}` => {pformat(accept_addrs)}\n'
+                    # ^-TODO-^ we should instead show the maddr here^^
                 )
 
                 # TODO: ideally we don't fan out to all registrars
@@ -1776,57 +1853,90 @@ async def async_main(
 
         # Blocks here as expected until the root nursery is
         # killed (i.e. this actor is cancelled or signalled by the parent)
-    except Exception as err:
-        log.runtime("Closing all actor lifetime contexts")
-        actor.lifetime_stack.close()
-
+    except Exception as internal_err:
         if not is_registered:
+            err_report: str = (
+                '\n'
+                "Actor runtime (internally) failed BEFORE contacting the registry?\n"
+                f'registrars -> {actor.reg_addrs} ?!?!\n\n'
+
+                '^^^ THIS IS PROBABLY AN INTERNAL `tractor` BUG! ^^^\n\n'
+                '\t>> CALMLY CANCEL YOUR CHILDREN AND CALL YOUR PARENTS <<\n\n'
+
+                '\tIf this is a sub-actor hopefully its parent will keep running '
+                'and cancel/reap this sub-process..\n'
+                '(well, presuming this error was propagated upward)\n\n'
+
+                '\t---------------------------------------------\n'
+                '\tPLEASE REPORT THIS TRACEBACK IN A BUG REPORT @ '  # oneline
+                'https://github.com/goodboy/tractor/issues\n'
+                '\t---------------------------------------------\n'
+            )
+
             # TODO: I guess we could try to connect back
             # to the parent through a channel and engage a debugger
             # once we have that all working with std streams locking?
-            log.exception(
-                f"Actor errored and failed to register with arbiter "
-                f"@ {actor.reg_addrs[0]}?")
-            log.error(
-                "\n\n\t^^^ THIS IS PROBABLY AN INTERNAL `tractor` BUG! ^^^\n\n"
-                "\t>> CALMLY CALL THE AUTHORITIES AND HIDE YOUR CHILDREN <<\n\n"
-                "\tIf this is a sub-actor hopefully its parent will keep running "
-                "correctly presuming this error was safely ignored..\n\n"
-                "\tPLEASE REPORT THIS TRACEBACK IN A BUG REPORT: "
-                "https://github.com/goodboy/tractor/issues\n"
-            )
+            log.exception(err_report)
 
         if actor._parent_chan:
             await try_ship_error_to_remote(
                 actor._parent_chan,
-                err,
+                internal_err,
             )
 
         # always!
-        match err:
+        match internal_err:
             case ContextCancelled():
                 log.cancel(
                     f'Actor: {actor.uid} was task-context-cancelled with,\n'
-                    f'str(err)'
+                    f'str(internal_err)'
                 )
             case _:
-                log.exception("Actor errored:")
-        raise
+                log.exception(
+                    'Main actor-runtime task errored\n'
+                    f'<x)\n'
+                    f' |_{actor}\n'
+                )
+
+        raise internal_err
 
     finally:
-        log.runtime(
-            'Runtime nursery complete'
-            '-> Closing all actor lifetime contexts..'
+        teardown_report: str = (
+            'Main actor-runtime task completed\n'
         )
-        # tear down all lifetime contexts if not in guest mode
-        # XXX: should this just be in the entrypoint?
-        actor.lifetime_stack.close()
 
-        # TODO: we can't actually do this bc the debugger
-        # uses the _service_n to spawn the lock task, BUT,
-        # in theory if we had the root nursery surround this finally
-        # block it might be actually possible to debug THIS
-        # machinery in the same way as user task code?
+        # ?TODO? should this be in `._entry`/`._root` mods instead?
+        #
+        # teardown any actor-lifetime-bound contexts
+        ls: ExitStack = actor.lifetime_stack
+        # only report if there are any registered
+        cbs: list[Callable] = [
+            repr(tup[1].__wrapped__)
+            for tup in ls._exit_callbacks
+        ]
+        if cbs:
+            cbs_str: str = '\n'.join(cbs)
+            teardown_report += (
+                '-> Closing actor-lifetime-bound callbacks\n\n'
+                f'}}>\n'
+                f' |_{ls}\n'
+                f'   |_{cbs_str}\n'
+            )
+            # XXX NOTE XXX this will cause an error which
+            # prevents any `infected_aio` actor from continuing
+            # and any callbacks in the `ls` here WILL NOT be
+            # called!!
+            # await _debug.pause(shield=True)
+
+        ls.close()
+
+        # XXX TODO but hard XXX
+        # we can't actually do this bc the debugger uses the
+        # _service_n to spawn the lock task, BUT, in theory if we had
+        # the root nursery surround this finally block it might be
+        # actually possible to debug THIS machinery in the same way
+        # as user task code?
+        #
         # if actor.name == 'brokerd.ib':
         #     with CancelScope(shield=True):
         #         await _debug.breakpoint()
@@ -1856,9 +1966,9 @@ async def async_main(
                     failed = True
 
                 if failed:
-                    log.warning(
-                        f'Failed to unregister {actor.name} from '
-                        f'registar @ {addr}'
+                    teardown_report += (
+                        f'-> Failed to unregister {actor.name} from '
+                        f'registar @ {addr}\n'
                     )
 
         # Ensure all peers (actors connected to us as clients) are finished
@@ -1866,13 +1976,23 @@ async def async_main(
             if any(
                 chan.connected() for chan in chain(*actor._peers.values())
             ):
-                log.runtime(
-                    f"Waiting for remaining peers {actor._peers} to clear")
+                teardown_report += (
+                    f'-> Waiting for remaining peers {actor._peers} to clear..\n'
+                )
+                log.runtime(teardown_report)
                 with CancelScope(shield=True):
                     await actor._no_more_peers.wait()
-        log.runtime("All peer channels are complete")
 
-    log.runtime("Runtime completed")
+        teardown_report += (
+            '-> All peer channels are complete\n'
+        )
+
+    teardown_report += (
+        'Actor runtime exiting\n'
+        f'>)\n'
+        f'|_{actor}\n'
+    )
+    log.info(teardown_report)
 
 
 # TODO: rename to `Registry` and move to `._discovery`!

tractor/_spawn.py

@@ -149,7 +149,7 @@ async def exhaust_portal(
 
         # XXX: streams should never be reaped here since they should
         # always be established and shutdown using a context manager api
-        final: Any = await portal.result()
+        final: Any = await portal.wait_for_result()
 
     except (
         Exception,
@@ -223,8 +223,8 @@ async def cancel_on_completion(
 
 async def hard_kill(
     proc: trio.Process,
-    terminate_after: int = 1.6,
 
+    terminate_after: int = 1.6,
     # NOTE: for mucking with `.pause()`-ing inside the runtime
     # whilst also hacking on it XD
     # terminate_after: int = 99999,
@@ -246,8 +246,9 @@ async def hard_kill(
 
     '''
     log.cancel(
-        'Terminating sub-proc:\n'
-        f'|_{proc}\n'
+        'Terminating sub-proc\n'
+        f'>x)\n'
+        f' |_{proc}\n'
     )
     # NOTE: this timeout used to do nothing since we were shielding
     # the ``.wait()`` inside ``new_proc()`` which will pretty much
@@ -293,8 +294,8 @@ async def hard_kill(
         log.critical(
             # 'Well, the #ZOMBIE_LORD_IS_HERE# to collect\n'
             '#T-800 deployed to collect zombie B0\n'
-            f'|\n'
-            f'|_{proc}\n'
+            f'>x)\n'
+            f' |_{proc}\n'
         )
         proc.kill()
 
@@ -322,8 +323,9 @@ async def soft_kill(
     uid: tuple[str, str] = portal.channel.uid
     try:
         log.cancel(
-            'Soft killing sub-actor via `Portal.cancel_actor()`\n'
-            f'|_{proc}\n'
+            'Soft killing sub-actor via portal request\n'
+            f'c)> {portal.chan.uid}\n'
+            f' |_{proc}\n'
         )
         # wait on sub-proc to signal termination
         await wait_func(proc)
@@ -552,8 +554,9 @@ async def trio_proc(
             # cancel result waiter that may have been spawned in
             # tandem if not done already
             log.cancel(
-                'Cancelling existing result waiter task for '
-                f'{subactor.uid}'
+                'Cancelling portal result reaper task\n'
+                f'>c)\n'
+                f' |_{subactor.uid}\n'
             )
             nursery.cancel_scope.cancel()
 
@@ -562,7 +565,11 @@ async def trio_proc(
         # allowed! Do this **after** cancellation/teardown to avoid
         # killing the process too early.
         if proc:
-            log.cancel(f'Hard reap sequence starting for {subactor.uid}')
+            log.cancel(
+                f'Hard reap sequence starting for subactor\n'
+                f'>x)\n'
+                f' |_{subactor}@{subactor.uid}\n'
+            )
 
             with trio.CancelScope(shield=True):
                 # don't clobber an ongoing pdb

tractor/_state.py

@@ -44,7 +44,9 @@ _runtime_vars: dict[str, Any] = {
     '_root_mailbox': (None, None),
     '_registry_addrs': [],
 
-    # for `breakpoint()` support
+    '_is_infected_aio': False,
+
+    # for `tractor.pause_from_sync()` & `breakpoint()` support
     'use_greenback': False,
 }
 
@@ -70,7 +72,8 @@ def current_actor(
     '''
     if (
         err_on_no_runtime
-        and _current_actor is None
+        and
+        _current_actor is None
     ):
         msg: str = 'No local actor has been initialized yet?\n'
         from ._exceptions import NoRuntime

tractor/_streaming.py

@@ -36,8 +36,8 @@ import warnings
 import trio
 
 from ._exceptions import (
-    # _raise_from_no_key_in_msg,
     ContextCancelled,
+    RemoteActorError,
 )
 from .log import get_logger
 from .trionics import (
@@ -101,7 +101,7 @@ class MsgStream(trio.abc.Channel):
     @property
     def ctx(self) -> Context:
         '''
-        This stream's IPC `Context` ref.
+        A read-only ref to this stream's inter-actor-task `Context`.
 
         '''
         return self._ctx
@@ -145,9 +145,8 @@ class MsgStream(trio.abc.Channel):
         '''
         __tracebackhide__: bool = hide_tb
 
-        # NOTE: `trio.ReceiveChannel` implements
-        # EOC handling as follows (aka uses it
-        # to gracefully exit async for loops):
+        # NOTE FYI: `trio.ReceiveChannel` implements EOC handling as
+        # follows (aka uses it to gracefully exit async for loops):
         #
         # async def __anext__(self) -> ReceiveType:
         #     try:
@@ -165,48 +164,29 @@ class MsgStream(trio.abc.Channel):
 
         src_err: Exception|None = None  # orig tb
         try:
-
             ctx: Context = self._ctx
             return await ctx._pld_rx.recv_pld(ipc=self)
 
         # XXX: the stream terminates on either of:
-        # - via `self._rx_chan.receive()` raising  after manual closure
-        #   by the rpc-runtime OR,
-        # - via a received `{'stop': ...}` msg from remote side.
-        #   |_ NOTE: previously this was triggered by calling
-        #   ``._rx_chan.aclose()`` on the send side of the channel inside
-        #   `Actor._deliver_ctx_payload()`, but now the 'stop' message handling
-        #   has been put just above inside `_raise_from_no_key_in_msg()`.
-        except (
-            trio.EndOfChannel,
-        ) as eoc:
-            src_err = eoc
+        # - `self._rx_chan.receive()` raising  after manual closure
+        #   by the rpc-runtime,
+        #   OR
+        # - via a `Stop`-msg received from remote peer task.
+        #   NOTE
+        #   |_ previously this was triggered by calling
+        #   ``._rx_chan.aclose()`` on the send side of the channel
+        #   inside `Actor._deliver_ctx_payload()`, but now the 'stop'
+        #   message handling gets delegated to `PldRFx.recv_pld()`
+        #   internals.
+        except trio.EndOfChannel as eoc:
+            # a graceful stream finished signal
             self._eoc = eoc
+            src_err = eoc
 
-            # TODO: Locally, we want to close this stream gracefully, by
-            # terminating any local consumers tasks deterministically.
-            # Once we have broadcast support, we **don't** want to be
-            # closing this stream and not flushing a final value to
-            # remaining (clone) consumers who may not have been
-            # scheduled to receive it yet.
-            # try:
-            #     maybe_err_msg_or_res: dict = self._rx_chan.receive_nowait()
-            #     if maybe_err_msg_or_res:
-            #         log.warning(
-            #             'Discarding un-processed msg:\n'
-            #             f'{maybe_err_msg_or_res}'
-            #         )
-            # except trio.WouldBlock:
-            #     # no queued msgs that might be another remote
-            #     # error, so just raise the original EoC
-            #     pass
-
-            # raise eoc
-
-        # a ``ClosedResourceError`` indicates that the internal
-        # feeder memory receive channel was closed likely by the
-        # runtime after the associated transport-channel
-        # disconnected or broke.
+        # a `ClosedResourceError` indicates that the internal feeder
+        # memory receive channel was closed likely by the runtime
+        # after the associated transport-channel disconnected or
+        # broke.
         except trio.ClosedResourceError as cre:  # by self._rx_chan.receive()
             src_err = cre
             log.warning(
@@ -218,14 +198,15 @@ class MsgStream(trio.abc.Channel):
         # terminated and signal this local iterator to stop
         drained: list[Exception|dict] = await self.aclose()
         if drained:
+            # ?TODO? pass these to the `._ctx._drained_msgs: deque`
+            # and then iterate them as part of any `.wait_for_result()` call?
+            #
             # from .devx import pause
             # await pause()
             log.warning(
-                'Drained context msgs during closure:\n'
+                'Drained context msgs during closure\n\n'
                 f'{drained}'
             )
-        # TODO: pass these to the `._ctx._drained_msgs: deque`
-        # and then iterate them as part of any `.result()` call?
 
         # NOTE XXX: if the context was cancelled or remote-errored
         # but we received the stream close msg first, we
@@ -238,28 +219,36 @@ class MsgStream(trio.abc.Channel):
             from_src_exc=src_err,
         )
 
-        # propagate any error but hide low-level frame details
-        # from the caller by default for debug noise reduction.
+        # propagate any error but hide low-level frame details from
+        # the caller by default for console/debug-REPL noise
+        # reduction.
         if (
             hide_tb
+            and (
 
-            # XXX NOTE XXX don't reraise on certain
-            # stream-specific internal error types like,
+                # XXX NOTE special conditions: don't reraise on
+                # certain stream-specific internal error types like,
                 #
                 # - `trio.EoC` since we want to use the exact instance
                 #   to ensure that it is the error that bubbles upward
                 #   for silent absorption by `Context.open_stream()`.
-            and not self._eoc
+                not self._eoc
 
-            # - `RemoteActorError` (or `ContextCancelled`) if it gets
-            #   raised from `_raise_from_no_key_in_msg()` since we
-            #   want the same (as the above bullet) for any
-            #   `.open_context()` block bubbled error raised by
-            #   any nearby ctx API remote-failures.
-            # and not isinstance(src_err, RemoteActorError)
+                # - `RemoteActorError` (or subtypes like ctxc)
+                #    since we want to present the error as though it is
+                #    "sourced" directly from this `.receive()` call and
+                #    generally NOT include the stack frames raised from
+                #    inside the `PldRx` and/or the transport stack
+                #    layers.
+                or isinstance(src_err, RemoteActorError)
+            )
         ):
             raise type(src_err)(*src_err.args) from src_err
         else:
+            # for any non-graceful-EOC we want to NOT hide this frame
+            if not self._eoc:
+                __tracebackhide__: bool = False
+
             raise src_err
 
     async def aclose(self) -> list[Exception|dict]:
@@ -385,6 +374,8 @@ class MsgStream(trio.abc.Channel):
         if not self._eoc:
             message: str = (
                 f'Stream self-closed by {self._ctx.side!r}-side before EoC\n'
+                # } bc a stream is a "scope"/msging-phase inside an IPC
+                f'x}}>\n'
                 f'|_{self}\n'
             )
             log.cancel(message)

tractor/_supervise.py

@@ -80,6 +80,7 @@ class ActorNursery:
     '''
     def __init__(
         self,
+        # TODO: maybe def these as fields of a struct looking type?
         actor: Actor,
         ria_nursery: trio.Nursery,
         da_nursery: trio.Nursery,
@@ -88,8 +89,10 @@ class ActorNursery:
     ) -> None:
         # self.supervisor = supervisor  # TODO
         self._actor: Actor = actor
-        self._ria_nursery = ria_nursery
+
+        # TODO: rename to `._tn` for our conventional "task-nursery"
         self._da_nursery = da_nursery
+
         self._children: dict[
             tuple[str, str],
             tuple[
@@ -98,15 +101,13 @@ class ActorNursery:
                 Portal | None,
             ]
         ] = {}
-        # portals spawned with ``run_in_actor()`` are
-        # cancelled when their "main" result arrives
-        self._cancel_after_result_on_exit: set = set()
+
         self.cancelled: bool = False
         self._join_procs = trio.Event()
         self._at_least_one_child_in_debug: bool = False
         self.errors = errors
-        self.exited = trio.Event()
         self._scope_error: BaseException|None = None
+        self.exited = trio.Event()
 
         # NOTE: when no explicit call is made to
         # `.open_root_actor()` by application code,
@@ -116,6 +117,13 @@ class ActorNursery:
         # and syncing purposes to any actor opened nurseries.
         self._implicit_runtime_started: bool = False
 
+        # TODO: remove the `.run_in_actor()` API and thus this 2ndary
+        # nursery when that API get's moved outside this primitive!
+        self._ria_nursery = ria_nursery
+        # portals spawned with ``run_in_actor()`` are
+        # cancelled when their "main" result arrives
+        self._cancel_after_result_on_exit: set = set()
+
     async def start_actor(
         self,
         name: str,
@@ -126,10 +134,14 @@ class ActorNursery:
         rpc_module_paths: list[str]|None = None,
         enable_modules: list[str]|None = None,
         loglevel: str|None = None,  # set log level per subactor
-        nursery: trio.Nursery|None = None,
         debug_mode: bool|None = None,
         infect_asyncio: bool = False,
 
+        # TODO: ideally we can rm this once we no longer have
+        # a `._ria_nursery` since the dependent APIs have been
+        # removed!
+        nursery: trio.Nursery|None = None,
+
     ) -> Portal:
         '''
         Start a (daemon) actor: an process that has no designated
@@ -146,6 +158,7 @@ class ActorNursery:
         # configure and pass runtime state
         _rtv = _state._runtime_vars.copy()
         _rtv['_is_root'] = False
+        _rtv['_is_infected_aio'] = infect_asyncio
 
         # allow setting debug policy per actor
         if debug_mode is not None:
@@ -200,6 +213,7 @@ class ActorNursery:
     #  |_ dynamic @context decoration on child side
     #  |_ implicit `Portal.open_context() as (ctx, first):`
     #    and `return first` on parent side.
+    #  |_ mention how it's similar to `trio-parallel` API?
     # -[ ] use @api_frame on the wrapper
     async def run_in_actor(
         self,
@@ -269,11 +283,14 @@ class ActorNursery:
 
     ) -> None:
         '''
-        Cancel this nursery by instructing each subactor to cancel
-        itself and wait for all subactors to terminate.
+        Cancel this actor-nursery by instructing each subactor's
+        runtime to cancel and wait for all underlying sub-processes
+        to terminate.
 
-        If ``hard_killl`` is set to ``True`` then kill the processes
-        directly without any far end graceful ``trio`` cancellation.
+        If `hard_kill` is set then kill the processes directly using
+        the spawning-backend's API/OS-machinery without any attempt
+        at (graceful) `trio`-style cancellation using our
+        `Actor.cancel()`.
 
         '''
         __runtimeframe__: int = 1  # noqa
@@ -357,11 +374,12 @@ class ActorNursery:
 @acm
 async def _open_and_supervise_one_cancels_all_nursery(
     actor: Actor,
+    tb_hide: bool = False,
 
 ) -> typing.AsyncGenerator[ActorNursery, None]:
 
     # normally don't need to show user by default
-    __tracebackhide__: bool = True
+    __tracebackhide__: bool = tb_hide
 
     outer_err: BaseException|None = None
     inner_err: BaseException|None = None
@@ -629,8 +647,12 @@ async def open_nursery(
             f'|_{an}\n'
         )
 
-        # shutdown runtime if it was started
         if implicit_runtime:
+            # shutdown runtime if it was started and report noisly
+            # that we're did so.
             msg += '=> Shutting down actor runtime <=\n'
-
             log.info(msg)
+
+        else:
+            # keep noise low during std operation.
+            log.runtime(msg)

tractor/_testing/__init__.py

@@ -54,6 +54,25 @@ def examples_dir() -> pathlib.Path:
     return repodir() / 'examples'
 
 
+def mk_cmd(
+    ex_name: str,
+    exs_subpath: str = 'debugging',
+) -> str:
+    '''
+    Generate a shell command suitable to pass to ``pexpect.spawn()``.
+
+    '''
+    script_path: pathlib.Path = (
+        examples_dir()
+        / exs_subpath
+        / f'{ex_name}.py'
+    )
+    return ' '.join([
+        'python',
+        str(script_path)
+    ])
+
+
 @acm
 async def expect_ctxc(
     yay: bool,

tractor/devx/__init__.py

@@ -26,9 +26,10 @@ from ._debug import (
     breakpoint as breakpoint,
     pause as pause,
     pause_from_sync as pause_from_sync,
-    shield_sigint_handler as shield_sigint_handler,
+    sigint_shield as sigint_shield,
     open_crash_handler as open_crash_handler,
     maybe_open_crash_handler as maybe_open_crash_handler,
+    maybe_init_greenback as maybe_init_greenback,
     post_mortem as post_mortem,
     mk_pdb as mk_pdb,
 )

tractor/devx/_frame_stack.py

@@ -234,7 +234,7 @@ def find_caller_info(
 _frame2callerinfo_cache: dict[FrameType, CallerInfo] = {}
 
 
-# TODO: -[x] move all this into new `.devx._code`!
+# TODO: -[x] move all this into new `.devx._frame_stack`!
 # -[ ] consider rename to _callstack?
 # -[ ] prolly create a `@runtime_api` dec?
 #   |_ @api_frame seems better?
@@ -286,3 +286,18 @@ def api_frame(
     wrapped._call_infos: dict[FrameType, CallerInfo] = _frame2callerinfo_cache
     wrapped.__api_func__: bool = True
     return wrapper(wrapped)
+
+
+# TODO: something like this instead of the adhoc frame-unhiding
+# blocks all over the runtime!! XD
+# -[ ] ideally we can expect a certain error (set) and if something
+#     else is raised then all frames below the wrapped one will be
+#     un-hidden via `__tracebackhide__: bool = False`.
+# |_ might need to dynamically mutate the code objs like
+#    `pdbp.hideframe()` does?
+# -[ ] use this as a `@acm` decorator as introed in 3.10?
+# @acm
+# async def unhide_frame_when_not(
+#     error_set: set[BaseException],
+# ) -> TracebackType:
+#     ...

tractor/devx/_stackscope.py

@@ -24,13 +24,24 @@ disjoint, parallel executing tasks in separate actors.
 
 '''
 from __future__ import annotations
+# from functools import partial
+from threading import (
+    current_thread,
+    Thread,
+    RLock,
+)
 import multiprocessing as mp
 from signal import (
     signal,
+    getsignal,
     SIGUSR1,
 )
-import traceback
-from typing import TYPE_CHECKING
+# import traceback
+from types import ModuleType
+from typing import (
+    Callable,
+    TYPE_CHECKING,
+)
 
 import trio
 from tractor import (
@@ -51,26 +62,45 @@ if TYPE_CHECKING:
 
 @trio.lowlevel.disable_ki_protection
 def dump_task_tree() -> None:
-    import stackscope
-    from tractor.log import get_console_log
+    '''
+    Do a classic `stackscope.extract()` task-tree dump to console at
+    `.devx()` level.
 
+    '''
+    import stackscope
     tree_str: str = str(
         stackscope.extract(
             trio.lowlevel.current_root_task(),
             recurse_child_tasks=True
         )
     )
-    log = get_console_log(
-        name=__name__,
-        level='cancel',
-    )
     actor: Actor = _state.current_actor()
+    thr: Thread = current_thread()
     log.devx(
         f'Dumping `stackscope` tree for actor\n'
-        f'{actor.name}: {actor}\n'
-        f' |_{mp.current_process()}\n\n'
+        f'{actor.uid}:\n'
+        f'|_{mp.current_process()}\n'
+        f'  |_{thr}\n'
+        f'    |_{actor}\n\n'
+
+        # start-of-trace-tree delimiter (mostly for testing)
+        '------ - ------\n'
+        '\n'
+        +
         f'{tree_str}\n'
+        +
+        # end-of-trace-tree delimiter (mostly for testing)
+        f'\n'
+        f'------ {actor.uid!r} ------\n'
     )
+    # TODO: can remove this right?
+    # -[ ] was original code from author
+    #
+    # print(
+    #     'DUMPING FROM PRINT\n'
+    #     +
+    #     content
+    # )
     # import logging
     # try:
     #     with open("/dev/tty", "w") as tty:
@@ -80,58 +110,130 @@ def dump_task_tree() -> None:
     #         "task_tree"
     #     ).exception("Error printing task tree")
 
+_handler_lock = RLock()
+_tree_dumped: bool = False
 
-def signal_handler(
+
+def dump_tree_on_sig(
     sig: int,
     frame: object,
 
     relay_to_subs: bool = True,
 
 ) -> None:
+    global _tree_dumped, _handler_lock
+    with _handler_lock:
+        if _tree_dumped:
+            log.warning(
+                'Already dumped for this actor...??'
+            )
+            return
+
+        _tree_dumped = True
+
+        # actor: Actor = _state.current_actor()
+        log.devx(
+            'Trying to dump `stackscope` tree..\n'
+        )
         try:
-        trio.lowlevel.current_trio_token(
-        ).run_sync_soon(dump_task_tree)
+            dump_task_tree()
+            # await actor._service_n.start_soon(
+            #     partial(
+            #         trio.to_thread.run_sync,
+            #         dump_task_tree,
+            #     )
+            # )
+            # trio.lowlevel.current_trio_token().run_sync_soon(
+            #     dump_task_tree
+            # )
+
         except RuntimeError:
+            log.exception(
+                'Failed to dump `stackscope` tree..\n'
+            )
             # not in async context -- print a normal traceback
-        traceback.print_stack()
+            # traceback.print_stack()
+            raise
+
+        except BaseException:
+            log.exception(
+                'Failed to dump `stackscope` tree..\n'
+            )
+            raise
+
+        log.devx(
+            'Supposedly we dumped just fine..?'
+        )
 
     if not relay_to_subs:
         return
 
     an: ActorNursery
     for an in _state.current_actor()._actoruid2nursery.values():
-
         subproc: ProcessType
         subactor: Actor
         for subactor, subproc, _ in an._children.values():
-            log.devx(
+            log.warning(
                 f'Relaying `SIGUSR1`[{sig}] to sub-actor\n'
                 f'{subactor}\n'
                 f' |_{subproc}\n'
             )
 
-            if isinstance(subproc, trio.Process):
+            # bc of course stdlib can't have a std API.. XD
+            match subproc:
+                case trio.Process():
                     subproc.send_signal(sig)
 
-            elif isinstance(subproc, mp.Process):
+                case mp.Process():
                     subproc._send_signal(sig)
 
 
 def enable_stack_on_sig(
-    sig: int = SIGUSR1
-) -> None:
+    sig: int = SIGUSR1,
+) -> ModuleType:
     '''
     Enable `stackscope` tracing on reception of a signal; by
     default this is SIGUSR1.
 
+    HOT TIP: a task/ctx-tree dump can be triggered from a shell with
+    fancy cmds.
+
+    For ex. from `bash` using `pgrep` and cmd-sustitution
+    (https://www.gnu.org/software/bash/manual/bash.html#Command-Substitution)
+    you could use:
+
+    >> kill -SIGUSR1 $(pgrep -f '<cmd>')
+
+    Or with with `xonsh` (which has diff capture-from-subproc syntax)
+
+    >> kill -SIGUSR1 @$(pgrep -f '<cmd>')
+
     '''
+    try:
+        import stackscope
+    except ImportError:
+        log.warning(
+            '`stackscope` not installed for use in debug mode!'
+        )
+        return None
+
+    handler: Callable|int = getsignal(sig)
+    if handler is dump_tree_on_sig:
+        log.devx(
+            'A `SIGUSR1` handler already exists?\n'
+            f'|_ {handler!r}\n'
+        )
+        return
+
     signal(
         sig,
-        signal_handler,
+        dump_tree_on_sig,
     )
-    # NOTE: not the above can be triggered from
-    # a (xonsh) shell using:
-    # kill -SIGUSR1 @$(pgrep -f '<cmd>')
-    #
-    # for example if you were looking to trace a `pytest` run
-    # kill -SIGUSR1 @$(pgrep -f 'pytest')
+    log.devx(
+        'Enabling trace-trees on `SIGUSR1` '
+        'since `stackscope` is installed @ \n'
+        f'{stackscope!r}\n\n'
+        f'With `SIGUSR1` handler\n'
+        f'|_{dump_tree_on_sig}\n'
+    )
+    return stackscope

tractor/devx/pformat.py

@@ -53,6 +53,7 @@ def pformat_boxed_tb(
 
     tb_box_indent: int|None = None,
     tb_body_indent: int = 1,
+    boxer_header: str = '-'
 
 ) -> str:
     '''
@@ -88,9 +89,9 @@ def pformat_boxed_tb(
 
     tb_box: str = (
         f'|\n'
-        f' ------ - ------\n'
+        f' ------ {boxer_header} ------\n'
         f'{tb_body}'
-        f' ------ - ------\n'
+        f' ------ {boxer_header}- ------\n'
         f'_|\n'
     )
     tb_box_indent: str = (

tractor/log.py

@@ -54,11 +54,12 @@ LOG_FORMAT = (
 DATE_FORMAT = '%b %d %H:%M:%S'
 
 # FYI, ERROR is 40
+# TODO: use a `bidict` to avoid the :155 check?
 CUSTOM_LEVELS: dict[str, int] = {
     'TRANSPORT': 5,
     'RUNTIME': 15,
     'DEVX': 17,
-    'CANCEL': 18,
+    'CANCEL': 22,
     'PDB': 500,
 }
 STD_PALETTE = {
@@ -147,6 +148,8 @@ class StackLevelAdapter(LoggerAdapter):
         Delegate a log call to the underlying logger, after adding
         contextual information from this adapter instance.
 
+        NOTE: all custom level methods (above) delegate to this!
+
         '''
         if self.isEnabledFor(level):
             stacklevel: int = 3

tractor/msg/_codec.py

@@ -41,8 +41,10 @@ import textwrap
 from typing import (
     Any,
     Callable,
+    Protocol,
     Type,
     TYPE_CHECKING,
+    TypeVar,
     Union,
 )
 from types import ModuleType
@@ -181,7 +183,11 @@ def mk_dec(
     dec_hook: Callable|None = None,
 
 ) -> MsgDec:
+    '''
+    Create an IPC msg decoder, normally used as the
+    `PayloadMsg.pld: PayloadT` field decoder inside a `PldRx`.
 
+    '''
     return MsgDec(
         _dec=msgpack.Decoder(
             type=spec,  # like `MsgType[Any]`
@@ -227,6 +233,13 @@ def pformat_msgspec(
     join_char: str = '\n',
 
 ) -> str:
+    '''
+    Pretty `str` format the `msgspec.msgpack.Decoder.type` attribute
+    for display in (console) log messages as a nice (maybe multiline)
+    presentation of all supported `Struct`s (subtypes) available for
+    typed decoding.
+
+    '''
     dec: msgpack.Decoder = getattr(codec, 'dec', codec)
     return join_char.join(
         mk_msgspec_table(
@@ -630,31 +643,57 @@ def limit_msg_spec(
 #         # import pdbp; pdbp.set_trace()
 #         assert ext_codec.pld_spec == extended_spec
 #         yield ext_codec
+#
+# ^-TODO-^ is it impossible to make something like this orr!?
+
+# TODO: make an auto-custom hook generator from a set of input custom
+# types?
+# -[ ] below is a proto design using a `TypeCodec` idea?
+#
+# type var for the expected interchange-lib's
+# IPC-transport type when not available as a built-in
+# serialization output.
+WireT = TypeVar('WireT')
 
 
-# TODO: make something similar to this inside `._codec` such that
-# user can just pass a type table of some sort?
-# -[ ] we would need to decode all msgs to `pretty_struct.Struct`
-#     and then call `.to_dict()` on them?
-# -[x] we're going to need to re-impl all the stuff changed in the
-#    runtime port such that it can handle dicts or `Msg`s?
-#
-# def mk_dict_msg_codec_hooks() -> tuple[Callable, Callable]:
-#     '''
-#     Deliver a `enc_hook()`/`dec_hook()` pair which does
-#     manual convertion from our above native `Msg` set
-#     to `dict` equivalent (wire msgs) in order to keep legacy compat
-#     with the original runtime implementation.
-#
-#     Note: this is is/was primarly used while moving the core
-#     runtime over to using native `Msg`-struct types wherein we
-#     start with the send side emitting without loading
-#     a typed-decoder and then later flipping the switch over to
-#     load to the native struct types once all runtime usage has
-#     been adjusted appropriately.
-#
-#     '''
-#     return (
-#         # enc_to_dict,
-#         dec_from_dict,
-#     )
+# TODO: some kinda (decorator) API for built-in subtypes
+# that builds this implicitly by inspecting the `mro()`?
+class TypeCodec(Protocol):
+    '''
+    A per-custom-type wire-transport serialization translator
+    description type.
+
+    '''
+    src_type: Type
+    wire_type: WireT
+
+    def encode(obj: Type) -> WireT:
+        ...
+
+    def decode(
+        obj_type: Type[WireT],
+        obj: WireT,
+    ) -> Type:
+        ...
+
+
+class MsgpackTypeCodec(TypeCodec):
+    ...
+
+
+def mk_codec_hooks(
+    type_codecs: list[TypeCodec],
+
+) -> tuple[Callable, Callable]:
+    '''
+    Deliver a `enc_hook()`/`dec_hook()` pair which handle
+    manual convertion from an input `Type` set such that whenever
+    the `TypeCodec.filter()` predicate matches the
+    `TypeCodec.decode()` is called on the input native object by
+    the `dec_hook()` and whenever the
+    `isiinstance(obj, TypeCodec.type)` matches against an
+    `enc_hook(obj=obj)` the return value is taken from a
+    `TypeCodec.encode(obj)` callback.
+
+    '''
+    ...

tractor/msg/_ops.py

@@ -374,7 +374,7 @@ class PldRx(Struct):
 
             case _:
                 src_err = InternalError(
-                    'Unknown IPC msg ??\n\n'
+                    'Invalid IPC msg ??\n\n'
                     f'{msg}\n'
                 )
 
@@ -499,7 +499,7 @@ async def maybe_limit_plds(
         yield None
         return
 
-    # sanity on scoping
+    # sanity check on IPC scoping
     curr_ctx: Context = current_ipc_ctx()
     assert ctx is curr_ctx
 
@@ -510,6 +510,8 @@ async def maybe_limit_plds(
     ) as msgdec:
         yield msgdec
 
+    # when the applied spec is unwound/removed, the same IPC-ctx
+    # should still be in scope.
     curr_ctx: Context = current_ipc_ctx()
     assert ctx is curr_ctx
 
@@ -525,16 +527,26 @@ async def drain_to_final_msg(
     list[MsgType]
 ]:
     '''
-    Drain IPC msgs delivered to the underlying IPC primitive's
-    rx-mem-chan (eg. `Context._rx_chan`) from the runtime in
-    search for a final result or error.
+    Drain IPC msgs delivered to the underlying IPC context's
+    rx-mem-chan (i.e. from `Context._rx_chan`) in search for a final
+    `Return` or `Error` msg.
 
-    The motivation here is to ideally capture errors during ctxc
-    conditions where a canc-request/or local error is sent but the
-    local task also excepts and enters the
-    `Portal.open_context().__aexit__()` block wherein we prefer to
-    capture and raise any remote error or ctxc-ack as part of the
-    `ctx.result()` cleanup and teardown sequence.
+    Deliver the `Return` + preceding drained msgs (`list[MsgType]`)
+    as a pair unless an `Error` is found, in which unpack and raise
+    it.
+
+    The motivation here is to always capture any remote error relayed
+    by the remote peer task during a ctxc condition.
+
+    For eg. a ctxc-request may be sent to the peer as part of the
+    local task's (request for) cancellation but then that same task
+    **also errors** before executing the teardown in the
+    `Portal.open_context().__aexit__()` block. In such error-on-exit
+    cases we want to always capture and raise any delivered remote
+    error (like an expected ctxc-ACK) as part of the final
+    `ctx.wait_for_result()` teardown sequence such that the
+    `Context.outcome` related state always reflect what transpired
+    even after ctx closure and the `.open_context()` block exit.
 
     '''
     __tracebackhide__: bool = hide_tb
@@ -572,22 +584,42 @@ async def drain_to_final_msg(
             # |_from tractor.devx._debug import pause
             #   await pause()
 
-
         # NOTE: we get here if the far end was
         # `ContextCancelled` in 2 cases:
         # 1. we requested the cancellation and thus
         #    SHOULD NOT raise that far end error,
         # 2. WE DID NOT REQUEST that cancel and thus
         #    SHOULD RAISE HERE!
-        except trio.Cancelled as taskc:
+        except trio.Cancelled as _taskc:
+            taskc: trio.Cancelled = _taskc
+
+            # report when the cancellation wasn't (ostensibly) due to
+            # RPC operation, some surrounding parent cancel-scope.
+            if not ctx._scope.cancel_called:
+                task: trio.lowlevel.Task = trio.lowlevel.current_task()
+                rent_n: trio.Nursery = task.parent_nursery
+                if (
+                    (local_cs := rent_n.cancel_scope).cancel_called
+                ):
+                    log.cancel(
+                        'RPC-ctx cancelled by local-parent scope during drain!\n\n'
+                        f'c}}>\n'
+                        f' |_{rent_n}\n'
+                        f'   |_.cancel_scope = {local_cs}\n'
+                        f'   |_>c}}\n'
+                        f'      |_{ctx.pformat(indent=" "*9)}'
+                        # ^TODO, some (other) simpler repr here?
+                    )
+                    __tracebackhide__: bool = False
 
             # CASE 2: mask the local cancelled-error(s)
             # only when we are sure the remote error is
             # the source cause of this local task's
             # cancellation.
             ctx.maybe_raise(
-                # TODO: when use this/
-                # from_src_exc=taskc,
+                hide_tb=hide_tb,
+                from_src_exc=taskc,
+                # ?TODO? when *should* we use this?
             )
 
             # CASE 1: we DID request the cancel we simply
@@ -659,7 +691,7 @@ async def drain_to_final_msg(
             # Stop()
             case Stop():
                 pre_result_drained.append(msg)
-                log.cancel(
+                log.runtime(  # normal/expected shutdown transaction
                     'Remote stream terminated due to "stop" msg:\n\n'
                     f'{pretty_struct.pformat(msg)}\n'
                 )
@@ -719,13 +751,19 @@ async def drain_to_final_msg(
                 pre_result_drained.append(msg)
                 # It's definitely an internal error if any other
                 # msg type without a`'cid'` field arrives here!
+                report: str = (
+                    f'Invalid or unknown msg type {type(msg)!r}!?\n'
+                )
                 if not msg.cid:
-                    raise InternalError(
-                        'Unexpected cid-missing msg?\n\n'
-                        f'{msg}\n'
+                    report += (
+                        '\nWhich also has no `.cid` field?\n'
                     )
 
-                raise RuntimeError('Unknown msg type: {msg}')
+                raise MessagingError(
+                    report
+                    +
+                    f'\n{msg}\n'
+                )
 
     else:
         log.cancel(

tractor/msg/pretty_struct.py

@@ -30,10 +30,13 @@ from msgspec import (
     Struct as _Struct,
     structs,
 )
-from pprint import (
-    saferepr,
-)
+# from pprint import (
+#     saferepr,
+# )
 
+from tractor.log import get_logger
+
+log = get_logger()
 # TODO: auto-gen type sig for input func both for
 # type-msgs and logging of RPC tasks?
 # taken and modified from:
@@ -72,8 +75,8 @@ class DiffDump(UserList):
         for k, left, right in self:
             repstr += (
                 f'({k},\n'
-                f'\t{repr(left)},\n'
-                f'\t{repr(right)},\n'
+                f' |_{repr(left)},\n'
+                f' |_{repr(right)},\n'
                 ')\n'
             )
         repstr += ']\n'
@@ -141,9 +144,22 @@ def pformat(
                 field_indent=indent + field_indent,
             )
 
-        else:  # the `pprint` recursion-safe format:
+        else:
+            val_str: str = repr(v)
+
+            # XXX LOL, below just seems to be f#$%in causing
+            # recursion errs..
+            #
+            # the `pprint` recursion-safe format:
             # https://docs.python.org/3.11/library/pprint.html#pprint.saferepr
-            val_str: str = saferepr(v)
+            # try:
+            #     val_str: str = saferepr(v)
+            # except Exception:
+            #     log.exception(
+            #         'Failed to `saferepr({type(struct)})` !?\n'
+            #     )
+                # raise
+                # return _Struct.__repr__(struct)
 
         # TODO: LOLOL use `textwrap.indent()` instead dawwwwwg!
         obj_str += (field_ws + f'{k}: {typ_name} = {val_str},\n')
@@ -194,12 +210,22 @@ class Struct(
         return sin_props
 
     pformat = pformat
+
+    def __repr__(self) -> str:
+        try:
+            return pformat(self)
+        except Exception:
+            log.exception(
+                f'Failed to `pformat({type(self)})` !?\n'
+            )
+            return _Struct.__repr__(self)
+
+    # __repr__ = pformat
     # __str__ = __repr__ = pformat
     # TODO: use a pprint.PrettyPrinter instance around ONLY rendering
     # inside a known tty?
     # def __repr__(self) -> str:
     #     ...
-    __repr__ = pformat
 
     def copy(
         self,
@@ -250,13 +276,15 @@ class Struct(
                 fi.type(getattr(self, fi.name)),
             )
 
+    # TODO: make a mod func instead and just point to it here for
+    # method impl?
     def __sub__(
         self,
         other: Struct,
 
     ) -> DiffDump[tuple[str, Any, Any]]:
         '''
-        Compare fields/items key-wise and return a ``DiffDump``
+        Compare fields/items key-wise and return a `DiffDump`
         for easy visual REPL comparison B)
 
         '''
@@ -273,3 +301,42 @@ class Struct(
                 ))
 
         return diffs
+
+    @classmethod
+    def fields_diff(
+        cls,
+        other: dict|Struct,
+
+    ) -> DiffDump[tuple[str, Any, Any]]:
+        '''
+        Very similar to `PrettyStruct.__sub__()` except accepts an
+        input `other: dict` (presumably that would normally be called
+        like `Struct(**other)`) which returns a `DiffDump` of the
+        fields of the struct and the `dict`'s fields.
+
+        '''
+        nullish = object()
+        consumed: dict = other.copy()
+        diffs: DiffDump[tuple[str, Any, Any]] = DiffDump()
+        for fi in structs.fields(cls):
+            field_name: str = fi.name
+            # ours: Any = getattr(self, field_name)
+            theirs: Any = consumed.pop(field_name, nullish)
+            if theirs is nullish:
+                diffs.append((
+                    field_name,
+                    f'{fi.type!r}',
+                    'NOT-DEFINED in `other: dict`',
+                ))
+
+        # when there are lingering fields in `other` that this struct
+        # DOES NOT define we also append those.
+        if consumed:
+            for k, v in consumed.items():
+                diffs.append((
+                    k,
+                    f'NOT-DEFINED for `{cls.__name__}`',
+                    f'`other: dict` has value = {v!r}',
+                ))
+
+        return diffs

tractor/to_asyncio.py

@@ -18,11 +18,13 @@
 Infection apis for ``asyncio`` loops running ``trio`` using guest mode.
 
 '''
+from __future__ import annotations
 import asyncio
 from asyncio.exceptions import CancelledError
 from contextlib import asynccontextmanager as acm
 from dataclasses import dataclass
 import inspect
+import traceback
 from typing import (
     Any,
     Callable,
@@ -30,25 +32,30 @@ from typing import (
     Awaitable,
 )
 
-import trio
-from outcome import Error
-
-from tractor.log import get_logger
+import tractor
+from tractor._exceptions import AsyncioCancelled
 from tractor._state import (
-    current_actor,
     debug_mode,
 )
 from tractor.devx import _debug
-from tractor._exceptions import AsyncioCancelled
+from tractor.log import get_logger
 from tractor.trionics._broadcast import (
     broadcast_receiver,
     BroadcastReceiver,
 )
+import trio
+from outcome import (
+    Error,
+    Outcome,
+)
 
 log = get_logger(__name__)
 
 
-__all__ = ['run_task', 'run_as_asyncio_guest']
+__all__ = [
+    'run_task',
+    'run_as_asyncio_guest',
+]
 
 
 @dataclass
@@ -152,16 +159,17 @@ def _run_asyncio_task(
     *,
     qsize: int = 1,
     provide_channels: bool = False,
+    hide_tb: bool = False,
     **kwargs,
 
 ) -> LinkedTaskChannel:
     '''
     Run an ``asyncio`` async function or generator in a task, return
-    or stream the result back to ``trio``.
+    or stream the result back to the caller `trio.lowleve.Task`.
 
     '''
-    __tracebackhide__ = True
-    if not current_actor().is_infected_aio():
+    __tracebackhide__: bool = hide_tb
+    if not tractor.current_actor().is_infected_aio():
         raise RuntimeError(
             "`infect_asyncio` mode is not enabled!?"
         )
@@ -172,7 +180,6 @@ def _run_asyncio_task(
     to_trio, from_aio = trio.open_memory_channel(qsize)  # type: ignore
 
     args = tuple(inspect.getfullargspec(func).args)
-
     if getattr(func, '_tractor_steam_function', None):
         # the assumption is that the target async routine accepts the
         # send channel then it intends to yield more then one return
@@ -222,6 +229,7 @@ def _run_asyncio_task(
         try:
             result = await coro
         except BaseException as aio_err:
+            chan._aio_err = aio_err
             if isinstance(aio_err, CancelledError):
                 log.runtime(
                     '`asyncio` task was cancelled..\n'
@@ -230,7 +238,6 @@ def _run_asyncio_task(
                 log.exception(
                     '`asyncio` task errored\n'
                 )
-            chan._aio_err = aio_err
             raise
 
         else:
@@ -238,14 +245,14 @@ def _run_asyncio_task(
                 result != orig and
                 aio_err is None and
 
-                # in the ``open_channel_from()`` case we don't
+                # in the `open_channel_from()` case we don't
                 # relay through the "return value".
                 not provide_channels
             ):
                 to_trio.send_nowait(result)
 
         finally:
-            # if the task was spawned using ``open_channel_from()``
+            # if the task was spawned using `open_channel_from()`
             # then we close the channels on exit.
             if provide_channels:
                 # only close the sender side which will relay
@@ -266,10 +273,13 @@ def _run_asyncio_task(
             aio_task_complete
         )
     )
-    chan._aio_task = task
+    chan._aio_task: asyncio.Task = task
 
     # XXX TODO XXX get this actually workin.. XD
-    # maybe setup `greenback` for `asyncio`-side task REPLing
+    # -[ ] we need logic to setup `greenback` for `asyncio`-side task
+    #     REPLing.. which should normally be nearly the same as for
+    #     `trio`?
+    # -[ ] add to a new `.devx._greenback.maybe_init_for_asyncio()`?
     if (
         debug_mode()
         and
@@ -282,31 +292,38 @@ def _run_asyncio_task(
 
     def cancel_trio(task: asyncio.Task) -> None:
         '''
-        Cancel the calling ``trio`` task on error.
+        Cancel the calling `trio` task on error.
 
         '''
         nonlocal chan
-        aio_err = chan._aio_err
+        aio_err: BaseException|None = chan._aio_err
         task_err: BaseException|None = None
 
-        # only to avoid ``asyncio`` complaining about uncaptured
+        # only to avoid `asyncio` complaining about uncaptured
         # task exceptions
         try:
-            task.exception()
+            res: Any = task.result()
         except BaseException as terr:
-            task_err = terr
+            task_err: BaseException = terr
 
             msg: str = (
                 'Infected `asyncio` task {etype_str}\n'
-                f'|_{task}\n'
             )
             if isinstance(terr, CancelledError):
+                msg += (
+                    f'c)>\n'
+                    f' |_{task}\n'
+                )
                 log.cancel(
                     msg.format(etype_str='cancelled')
                 )
             else:
+                msg += (
+                    f'x)>\n'
+                    f' |_{task}\n'
+                )
                 log.exception(
-                    msg.format(etype_str='cancelled')
+                    msg.format(etype_str='errored')
                 )
 
             assert type(terr) is type(aio_err), (
@@ -326,29 +343,45 @@ def _run_asyncio_task(
 
             if task_err is None:
                 assert aio_err
-                aio_err.with_traceback(aio_err.__traceback__)
-                # log.error(
-                #     'infected task errorred'
-                # )
+                # wait, wut?
+                # aio_err.with_traceback(aio_err.__traceback__)
 
-            # TODO: show that the cancellation originated
-            # from the ``trio`` side? right?
-            # elif type(aio_err) is CancelledError:
+            # TODO: show when cancellation originated
+            # from each side more pedantically?
+            # elif (
+            #     type(aio_err) is CancelledError
+            #     and  # trio was the cause?
+            #     cancel_scope.cancel_called
+            # ):
             #     log.cancel(
-            #         'infected task was cancelled'
+            #         'infected task was cancelled by `trio`-side'
             #     )
+            #     raise aio_err from task_err
 
-                # if cancel_scope.cancelled:
-                #     raise aio_err from err
-
-            # XXX: alway cancel the scope on error
-            # in case the trio task is blocking
-            # on a checkpoint.
+            # XXX: if not already, alway cancel the scope
+            # on a task error in case the trio task is blocking on
+            # a checkpoint.
             cancel_scope.cancel()
 
-            # raise any ``asyncio`` side error.
+            if (
+                task_err
+                and
+                aio_err is not task_err
+            ):
+                raise aio_err from task_err
+
+            # raise any `asyncio` side error.
             raise aio_err
 
+        log.info(
+            '`trio` received final result from {task}\n'
+            f'|_{res}\n'
+        )
+        # TODO: do we need this?
+        # if task_err:
+        #     cancel_scope.cancel()
+        #     raise task_err
+
     task.add_done_callback(cancel_trio)
     return chan
 
@@ -375,7 +408,9 @@ async def translate_aio_errors(
     ) -> None:
         aio_err = chan._aio_err
         if (
-            aio_err is not None and
+            aio_err is not None
+            and
+            # not isinstance(aio_err, CancelledError)
             type(aio_err) != CancelledError
         ):
             # always raise from any captured asyncio error
@@ -407,13 +442,17 @@ async def translate_aio_errors(
     ):
         aio_err = chan._aio_err
         if (
-            task.cancelled() and
+            task.cancelled()
+            and
             type(aio_err) is CancelledError
         ):
-            # if an underlying ``asyncio.CancelledError`` triggered this
+            # if an underlying `asyncio.CancelledError` triggered this
             # channel close, raise our (non-``BaseException``) wrapper
             # error: ``AsyncioCancelled`` from that source error.
-            raise AsyncioCancelled from aio_err
+            raise AsyncioCancelled(
+                f'Task cancelled\n'
+                f'|_{task}\n'
+            ) from aio_err
 
         else:
             raise
@@ -456,12 +495,12 @@ async def run_task(
 
 ) -> Any:
     '''
-    Run an ``asyncio`` async function or generator in a task, return
-    or stream the result back to ``trio``.
+    Run an `asyncio` async function or generator in a task, return
+    or stream the result back to `trio`.
 
     '''
     # simple async func
-    chan = _run_asyncio_task(
+    chan: LinkedTaskChannel = _run_asyncio_task(
         func,
         qsize=1,
         **kwargs,
@@ -491,7 +530,7 @@ async def open_channel_from(
     spawned ``asyncio`` task and ``trio``.
 
     '''
-    chan = _run_asyncio_task(
+    chan: LinkedTaskChannel = _run_asyncio_task(
         target,
         qsize=2**8,
         provide_channels=True,
@@ -515,11 +554,124 @@ async def open_channel_from(
                 chan._to_trio.close()
 
 
-def run_as_asyncio_guest(
+class AsyncioRuntimeTranslationError(RuntimeError):
+    '''
+    We failed to correctly relay runtime semantics and/or maintain SC
+    supervision rules cross-event-loop.
 
+    '''
+
+
+def run_trio_task_in_future(
+    async_fn,
+    *args,
+) -> asyncio.Future:
+    '''
+    Run an async-func as a `trio` task from an `asyncio.Task` wrapped
+    in a `asyncio.Future` which is returned to the caller.
+
+    Another astounding feat by the great @oremanj !!
+
+    Bo
+
+    '''
+    result_future = asyncio.Future()
+    cancel_scope = trio.CancelScope()
+    finished: bool = False
+
+    # monkey-patch the future's `.cancel()` meth to
+    # allow cancellation relay to `trio`-task.
+    cancel_message: str|None = None
+    orig_cancel = result_future.cancel
+
+    def wrapped_cancel(
+        msg: str|None = None,
+    ):
+        nonlocal cancel_message
+        if finished:
+            # We're being called back after the task completed
+            if msg is not None:
+                return orig_cancel(msg)
+            elif cancel_message is not None:
+                return orig_cancel(cancel_message)
+            else:
+                return orig_cancel()
+
+        if result_future.done():
+            return False
+
+        # Forward cancellation to the Trio task, don't mark
+        # future as cancelled until it completes
+        cancel_message = msg
+        cancel_scope.cancel()
+        return True
+
+    result_future.cancel = wrapped_cancel
+
+    async def trio_task() -> None:
+        nonlocal finished
+        try:
+            with cancel_scope:
+                try:
+                    # TODO: type this with new tech in 3.13
+                    result: Any = await async_fn(*args)
+                finally:
+                    finished = True
+
+            # Propagate result or cancellation to the Future
+            if cancel_scope.cancelled_caught:
+                result_future.cancel()
+
+            elif not result_future.cancelled():
+                result_future.set_result(result)
+
+        except BaseException as exc:
+            # the result future gets all the non-Cancelled
+            # exceptions. Any Cancelled need to keep propagating
+            # out of this stack frame in order to reach the cancel
+            # scope for which they're intended.
+            cancelled: BaseException|None
+            rest: BaseException|None
+            if isinstance(exc, BaseExceptionGroup):
+                cancelled, rest = exc.split(trio.Cancelled)
+
+            elif isinstance(exc, trio.Cancelled):
+                cancelled, rest = exc, None
+
+            else:
+                cancelled, rest = None, exc
+
+            if not result_future.cancelled():
+                if rest:
+                    result_future.set_exception(rest)
+                else:
+                    result_future.cancel()
+
+            if cancelled:
+                raise cancelled
+
+    trio.lowlevel.spawn_system_task(
+        trio_task,
+        name=async_fn,
+    )
+    return result_future
+
+
+def run_as_asyncio_guest(
     trio_main: Callable,
+    # ^-NOTE-^ when spawned with `infected_aio=True` this func is
+    # normally `Actor._async_main()` as is passed by some boostrap
+    # entrypoint like `._entry._trio_main()`.
+
+    _sigint_loop_pump_delay: float = 0,
 
 ) -> None:
+# ^-TODO-^ technically whatever `trio_main` returns.. we should
+# try to use func-typevar-params at leaast by 3.13!
+# -[ ] https://typing.readthedocs.io/en/latest/spec/callables.html#callback-protocols
+# -[ ] https://peps.python.org/pep-0646/#using-type-variable-tuples-in-functions
+# -[ ] https://typing.readthedocs.io/en/latest/spec/callables.html#unpack-for-keyword-arguments
+# -[ ] https://peps.python.org/pep-0718/
     '''
     Entry for an "infected ``asyncio`` actor".
 
@@ -545,51 +697,213 @@ def run_as_asyncio_guest(
     # :)
 
     async def aio_main(trio_main):
+        '''
+        Main `asyncio.Task` which calls
+        `trio.lowlevel.start_guest_run()` to "infect" the `asyncio`
+        event-loop by embedding the `trio` scheduler allowing us to
+        boot the `tractor` runtime and connect back to our parent.
 
+        '''
         loop = asyncio.get_running_loop()
-        trio_done_fut = asyncio.Future()
+        trio_done_fute = asyncio.Future()
+        startup_msg: str = (
+            'Starting `asyncio` guest-loop-run\n'
+            '-> got running loop\n'
+            '-> built a `trio`-done future\n'
+        )
 
-        if debug_mode():
-            # XXX make it obvi we know this isn't supported yet!
-            log.error(
-                'Attempting to enter unsupported `greenback` init '
-                'from `asyncio` task..'
-            )
-            await _debug.maybe_init_greenback(
-                force_reload=True,
-            )
+        # TODO: shoudn't this be done in the guest-run trio task?
+        # if debug_mode():
+        #     # XXX make it obvi we know this isn't supported yet!
+        #     log.error(
+        #         'Attempting to enter unsupported `greenback` init '
+        #         'from `asyncio` task..'
+        #     )
+        #     await _debug.maybe_init_greenback(
+        #         force_reload=True,
+        #     )
 
         def trio_done_callback(main_outcome):
+            log.runtime(
+                f'`trio` guest-run finishing with outcome\n'
+                f'>) {main_outcome}\n'
+                f'|_{trio_done_fute}\n'
+            )
 
             if isinstance(main_outcome, Error):
-                error = main_outcome.error
-                trio_done_fut.set_exception(error)
+                error: BaseException = main_outcome.error
 
-                # TODO: explicit asyncio tb?
-                # traceback.print_exception(error)
-
-                # XXX: do we need this?
-                # actor.cancel_soon()
+                # show an dedicated `asyncio`-side tb from the error
+                tb_str: str = ''.join(traceback.format_exception(error))
+                log.exception(
+                    'Guest-run errored!?\n\n'
+                    f'{main_outcome}\n'
+                    f'{error}\n\n'
+                    f'{tb_str}\n'
+                )
+                trio_done_fute.set_exception(error)
 
+                # raise inline
                 main_outcome.unwrap()
+
             else:
-                trio_done_fut.set_result(main_outcome)
-                log.runtime(f"trio_main finished: {main_outcome!r}")
+                trio_done_fute.set_result(main_outcome)
+
+            log.info(
+                f'`trio` guest-run finished with outcome\n'
+                f')>\n'
+                f'|_{trio_done_fute}\n'
+            )
+
+        startup_msg += (
+            f'-> created {trio_done_callback!r}\n'
+            f'-> scheduling `trio_main`: {trio_main!r}\n'
+        )
 
         # start the infection: run trio on the asyncio loop in "guest mode"
         log.runtime(
-            'Infecting `asyncio`-process with a `trio` guest-run of\n\n'
-            f'{trio_main!r}\n\n'
-
-            f'{trio_done_callback}\n'
+            f'{startup_msg}\n\n'
+            +
+            'Infecting `asyncio`-process with a `trio` guest-run!\n'
         )
+
         trio.lowlevel.start_guest_run(
             trio_main,
             run_sync_soon_threadsafe=loop.call_soon_threadsafe,
             done_callback=trio_done_callback,
         )
-        # NOTE `.unwrap()` will raise on error
-        return (await trio_done_fut).unwrap()
+        fute_err: BaseException|None = None
+        try:
+            out: Outcome = await asyncio.shield(trio_done_fute)
+
+            # NOTE will raise (via `Error.unwrap()`) from any
+            # exception packed into the guest-run's `main_outcome`.
+            return out.unwrap()
+
+        except (
+            # XXX special SIGINT-handling is required since
+            # `asyncio.shield()`-ing seems to NOT handle that case as
+            # per recent changes in 3.11:
+            # https://docs.python.org/3/library/asyncio-runner.html#handling-keyboard-interruption
+            #
+            # NOTE: further, apparently ONLY need to handle this
+            # special SIGINT case since all other `asyncio`-side
+            # errors can be processed via our `chan._aio_err`
+            # relaying (right?); SIGINT seems to be totally diff
+            # error path in `asyncio`'s runtime..?
+            asyncio.CancelledError,
+
+        ) as _fute_err:
+            fute_err = _fute_err
+            err_message: str = (
+                'main `asyncio` task '
+            )
+            if isinstance(fute_err, asyncio.CancelledError):
+                err_message += 'was cancelled!\n'
+            else:
+                err_message += f'errored with {out.error!r}\n'
+
+            actor: tractor.Actor = tractor.current_actor()
+            log.exception(
+                err_message
+                +
+                'Cancelling `trio`-side `tractor`-runtime..\n'
+                f'c)>\n'
+                f'  |_{actor}.cancel_soon()\n'
+            )
+
+            # XXX WARNING XXX the next LOCs are super important, since
+            # without them, we can get guest-run abandonment cases
+            # where `asyncio` will not schedule or wait on the `trio`
+            # guest-run task before final shutdown! This is
+            # particularly true if the `trio` side has tasks doing
+            # shielded work when a SIGINT condition occurs.
+            #
+            # We now have the
+            # `test_infected_asyncio.test_sigint_closes_lifetime_stack()`
+            # suite to ensure we do not suffer this issues
+            # (hopefully) ever again.
+            #
+            # The original abandonment issue surfaced as 2 different
+            # race-condition dependent types scenarios all to do with
+            # `asyncio` handling SIGINT from the system:
+            #
+            # - "silent-abandon" (WORST CASE):
+            #  `asyncio` abandons the `trio` guest-run task silently
+            #  and no `trio`-guest-run or `tractor`-actor-runtime
+            #  teardown happens whatsoever..
+            #
+            # - "loud-abandon" (BEST-ish CASE):
+            #   the guest run get's abaondoned "loudly" with `trio`
+            #   reporting a console traceback and further tbs of all
+            #   the (failed) GC-triggered shutdown routines which
+            #   thankfully does get dumped to console..
+            #
+            # The abandonment is most easily reproduced if the `trio`
+            # side has tasks doing shielded work where those tasks
+            # ignore the normal `Cancelled` condition and continue to
+            # run, but obviously `asyncio` isn't aware of this and at
+            # some point bails on the guest-run unless we take manual
+            # intervention..
+            #
+            # To repeat, *WITHOUT THIS* stuff below the guest-run can
+            # get race-conditionally abandoned!!
+            #
+            # XXX SOLUTION XXX
+            # ------ - ------
+            # XXX FIRST PART:
+            # ------ - ------
+            # the obvious fix to the "silent-abandon" case is to
+            # explicitly cancel the actor runtime such that no
+            # runtime tasks are even left unaware that the guest-run
+            # should be terminated due to OS cancellation.
+            #
+            actor.cancel_soon()
+
+            # ------ - ------
+            # XXX SECOND PART:
+            # ------ - ------
+            # Pump the `asyncio` event-loop to allow
+            # `trio`-side to `trio`-guest-run to complete and
+            # teardown !!
+            #
+            # oh `asyncio`, how i don't miss you at all XD
+            while not trio_done_fute.done():
+                log.runtime(
+                    'Waiting on main guest-run `asyncio` task to complete..\n'
+                    f'|_trio_done_fut: {trio_done_fute}\n'
+                )
+                await asyncio.sleep(_sigint_loop_pump_delay)
+
+                # XXX is there any alt API/approach like the internal
+                # call below but that doesn't block indefinitely..?
+                # loop._run_once()
+
+            try:
+                return trio_done_fute.result()
+            except asyncio.exceptions.InvalidStateError as state_err:
+
+                # XXX be super dupere noisy about abandonment issues!
+                aio_task: asyncio.Task = asyncio.current_task()
+                message: str = (
+                    'The `asyncio`-side task likely exited before the '
+                    '`trio`-side guest-run completed!\n\n'
+                )
+                if fute_err:
+                    message += (
+                        f'The main {aio_task}\n'
+                        f'STOPPED due to {type(fute_err)}\n\n'
+                    )
+
+                message += (
+                    f'Likely something inside our guest-run-as-task impl is '
+                    f'not effectively waiting on the `trio`-side to complete ?!\n'
+                    f'This code -> {aio_main!r}\n\n'
+
+                    'Below you will likely see a '
+                    '"RuntimeWarning: Trio guest run got abandoned.." !!\n'
+                )
+                raise AsyncioRuntimeTranslationError(message) from state_err
 
     # might as well if it's installed.
     try:
@@ -597,6 +911,8 @@ def run_as_asyncio_guest(
         loop = uvloop.new_event_loop()
         asyncio.set_event_loop(loop)
     except ImportError:
-        pass
+        log.runtime('`uvloop` not available..')
 
-    return asyncio.run(aio_main(trio_main))
+    return asyncio.run(
+        aio_main(trio_main),
+    )

tractor/trionics/_broadcast.py

@@ -156,11 +156,12 @@ class BroadcastState(Struct):
 
 class BroadcastReceiver(ReceiveChannel):
     '''
-    A memory receive channel broadcaster which is non-lossy for the
-    fastest consumer.
+    A memory receive channel broadcaster which is non-lossy for
+    the fastest consumer.
 
-    Additional consumer tasks can receive all produced values by registering
-    with ``.subscribe()`` and receiving from the new instance it delivers.
+    Additional consumer tasks can receive all produced values by
+    registering with ``.subscribe()`` and receiving from the new
+    instance it delivers.
 
     '''
     def __init__(
@@ -381,7 +382,7 @@ class BroadcastReceiver(ReceiveChannel):
                         # likely it makes sense to unwind back to the
                         # underlying?
                         # import tractor
-                        # await tractor.breakpoint()
+                        # await tractor.pause()
                         log.warning(
                             f'Only one sub left for {self}?\n'
                             'We can probably unwind from breceiver?'

tractor/trionics/_mngrs.py

@@ -18,8 +18,12 @@
 Async context manager primitives with hard ``trio``-aware semantics
 
 '''
-from contextlib import asynccontextmanager as acm
+from __future__ import annotations
+from contextlib import (
+    asynccontextmanager as acm,
+)
 import inspect
+from types import ModuleType
 from typing import (
     Any,
     AsyncContextManager,
@@ -30,13 +34,16 @@ from typing import (
     Optional,
     Sequence,
     TypeVar,
+    TYPE_CHECKING,
 )
 
 import trio
-
 from tractor._state import current_actor
 from tractor.log import get_logger
 
+if TYPE_CHECKING:
+    from tractor import ActorNursery
+
 
 log = get_logger(__name__)
 
@@ -46,8 +53,10 @@ T = TypeVar("T")
 
 @acm
 async def maybe_open_nursery(
-    nursery: trio.Nursery | None = None,
+    nursery: trio.Nursery|ActorNursery|None = None,
     shield: bool = False,
+    lib: ModuleType = trio,
+
 ) -> AsyncGenerator[trio.Nursery, Any]:
     '''
     Create a new nursery if None provided.
@@ -58,13 +67,12 @@ async def maybe_open_nursery(
     if nursery is not None:
         yield nursery
     else:
-        async with trio.open_nursery() as nursery:
+        async with lib.open_nursery() as nursery:
             nursery.cancel_scope.shield = shield
             yield nursery
 
 
 async def _enter_and_wait(
-
     mngr: AsyncContextManager[T],
     unwrapped: dict[int, T],
     all_entered: trio.Event,
@@ -91,7 +99,6 @@ async def _enter_and_wait(
 
 @acm
 async def gather_contexts(
-
     mngrs: Sequence[AsyncContextManager[T]],
 
 ) -> AsyncGenerator[
@@ -102,15 +109,17 @@ async def gather_contexts(
     None,
 ]:
     '''
-    Concurrently enter a sequence of async context managers, each in
-    a separate ``trio`` task and deliver the unwrapped values in the
-    same order once all managers have entered. On exit all contexts are
-    subsequently and concurrently exited.
+    Concurrently enter a sequence of async context managers (acms),
+    each from a separate `trio` task and deliver the unwrapped
+    `yield`-ed values in the same order once all managers have entered.
 
-    This function is somewhat similar to common usage of
-    ``contextlib.AsyncExitStack.enter_async_context()`` (in a loop) in
-    combo with ``asyncio.gather()`` except the managers are concurrently
-    entered and exited, and cancellation just works.
+    On exit, all acms are subsequently and concurrently exited.
+
+    This function is somewhat similar to a batch of non-blocking
+    calls to `contextlib.AsyncExitStack.enter_async_context()`
+    (inside a loop) *in combo with* a `asyncio.gather()` to get the
+    `.__aenter__()`-ed values, except the managers are both
+    concurrently entered and exited and *cancellation just works*(R).
 
     '''
     seed: int = id(mngrs)
@@ -210,9 +219,10 @@ async def maybe_open_context(
 
 ) -> AsyncIterator[tuple[bool, T]]:
     '''
-    Maybe open a context manager if there is not already a _Cached
-    version for the provided ``key`` for *this* actor. Return the
-    _Cached instance on a _Cache hit.
+    Maybe open an async-context-manager (acm) if there is not already
+    a `_Cached` version for the provided (input) `key` for *this* actor.
+
+    Return the `_Cached` instance on a _Cache hit.
 
     '''
     fid = id(acm_func)
@@ -273,8 +283,13 @@ async def maybe_open_context(
     else:
         _Cache.users += 1
         log.runtime(
-            f'Reusing resource for `_Cache` user {_Cache.users}\n\n'
-            f'{ctx_key!r} -> {yielded!r}\n'
+            f'Re-using cached resource for user {_Cache.users}\n\n'
+            f'{ctx_key!r} -> {type(yielded)}\n'
+
+            # TODO: make this work with values but without
+            # `msgspec.Struct` causing frickin crashes on field-type
+            # lookups..
+            # f'{ctx_key!r} -> {yielded!r}\n'
         )
         lock.release()
         yield True, yielded