Toss in masked `.set_trace()` for unshielded `.pause()` debug

Such that we handle them despite a cancellation condition. This is
almost always the case, that `root_tn.cancel_scope.cancel_called` is
set, by the time the `debug._maybe_enter_pm()` hits. Previous I guess we
just weren't actually ever REPL-debugging such cases? Still needs
a test obvi.

examples/advanced_faults/ipc_failure_during_stream.py

@@ -16,7 +16,6 @@ from tractor import (
     ContextCancelled,
     MsgStream,
     _testing,
-    trionics,
 )
 import trio
 import pytest
@@ -63,8 +62,9 @@ async def recv_and_spawn_net_killers(
     await ctx.started()
     async with (
         ctx.open_stream() as stream,
-        trionics.collapse_eg(),
-        trio.open_nursery() as tn,
+        trio.open_nursery(
+            strict_exception_groups=False,
+        ) as tn,
     ):
         async for i in stream:
             print(f'child echoing {i}')

examples/debugging/root_self_cancelled_w_error.py

@@ -1,35 +0,0 @@
-import trio
-import tractor
-
-
-async def main():
-    async with tractor.open_root_actor(
-        debug_mode=True,
-        loglevel='cancel',
-    ) as _root:
-
-        # manually trigger self-cancellation and wait
-        # for it to fully trigger.
-        _root.cancel_soon()
-        await _root._cancel_complete.wait()
-        print('root cancelled')
-
-        # now ensure we can still use the REPL
-        try:
-            await tractor.pause()
-        except trio.Cancelled as _taskc:
-            assert (root_cs := _root._root_tn.cancel_scope).cancel_called
-            # NOTE^^ above logic but inside `open_root_actor()` and
-            # passed to the `shield=` expression is effectively what
-            # we're testing here!
-            await tractor.pause(shield=root_cs.cancel_called)
-
-        # XXX, if shield logic *is wrong* inside `open_root_actor()`'s
-        # crash-handler block this should never be interacted,
-        # instead `trio.Cancelled` would be bubbled up: the original
-        # BUG.
-        assert 0
-
-
-if __name__ == '__main__':
-    trio.run(main)

examples/quick_cluster.py

@@ -23,8 +23,9 @@ async def main():
             modules=[__name__]
         ) as portal_map,
 
-        tractor.trionics.collapse_eg(),
-        trio.open_nursery() as tn,
+        trio.open_nursery(
+            strict_exception_groups=False,
+        ) as tn,
     ):
 
         for (name, portal) in portal_map.items():

tests/devx/test_debugger.py

@@ -1,13 +1,13 @@
 """
 That "native" debug mode better work!
 
-All these tests can be understood (somewhat) by running the
-equivalent `examples/debugging/` scripts manually.
+All these tests can be understood (somewhat) by running the equivalent
+`examples/debugging/` scripts manually.
 
 TODO:
-  - none of these tests have been run successfully on windows yet but
-    there's been manual testing that verified it works.
-  - wonder if any of it'll work on OS X?
+    - none of these tests have been run successfully on windows yet but
+      there's been manual testing that verified it works.
+    - wonder if any of it'll work on OS X?
 
 """
 from __future__ import annotations
@@ -1156,54 +1156,6 @@ def test_ctxep_pauses_n_maybe_ipc_breaks(
             )
 
 
-def test_crash_handling_within_cancelled_root_actor(
-    spawn: PexpectSpawner,
-):
-    '''
-    Ensure that when only a root-actor is started via `open_root_actor()`
-    we can crash-handle in debug-mode despite self-cancellation.
-
-    More-or-less ensures we conditionally shield the pause in
-    `._root.open_root_actor()`'s `await debug._maybe_enter_pm()`
-    call.
-
-    '''
-    child = spawn('root_self_cancelled_w_error')
-    child.expect(PROMPT)
-
-    assert_before(
-        child,
-        [
-            "Actor.cancel_soon()` was called!",
-            "root cancelled",
-            _pause_msg,
-            "('root'",  # actor name
-        ]
-    )
-
-    child.sendline('c')
-    child.expect(PROMPT)
-    assert_before(
-        child,
-        [
-            _crash_msg,
-            "('root'",  # actor name
-            "AssertionError",
-            "assert 0",
-        ]
-    )
-
-    child.sendline('c')
-    child.expect(EOF)
-    assert_before(
-        child,
-        [
-            "AssertionError",
-            "assert 0",
-        ]
-    )
-
-
 # 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

tests/ipc/test_each_tpt.py

@@ -18,9 +18,8 @@ from tractor import (
 @pytest.fixture
 def bindspace_dir_str() -> str:
 
-    rt_dir: Path = tractor._state.get_rt_dir()
-    bs_dir: Path = rt_dir / 'doggy'
-    bs_dir_str: str = str(bs_dir)
+    bs_dir_str: str = '/run/user/1000/doggy'
+    bs_dir = Path(bs_dir_str)
     assert not bs_dir.is_dir()
 
     yield bs_dir_str

tests/test_advanced_streaming.py

@@ -313,8 +313,9 @@ async def inf_streamer(
         # `trio.EndOfChannel` doesn't propagate directly to the above
         # .open_stream() parent, resulting in it also raising instead
         # of gracefully absorbing as normal.. so how to handle?
-        tractor.trionics.collapse_eg(),
-        trio.open_nursery() as tn,
+        trio.open_nursery(
+            strict_exception_groups=False,
+        ) as tn,
     ):
         async def close_stream_on_sentinel():
             async for msg in stream:

tests/test_cancellation.py

@@ -236,10 +236,7 @@ async def stream_forever():
 async def test_cancel_infinite_streamer(start_method):
 
     # stream for at most 1 seconds
-    with (
-        trio.fail_after(4),
-        trio.move_on_after(1) as cancel_scope
-    ):
+    with trio.move_on_after(1) as cancel_scope:
         async with tractor.open_nursery() as n:
             portal = await n.start_actor(
                 'donny',
@@ -535,15 +532,10 @@ def test_cancel_via_SIGINT_other_task(
     async def main():
         # should never timeout since SIGINT should cancel the current program
         with trio.fail_after(timeout):
-            async with (
-
-                # XXX ?TODO? why no work!?
-                # tractor.trionics.collapse_eg(),
-                trio.open_nursery(
-                    strict_exception_groups=False,
-                ) as tn,
-            ):
-                await tn.start(spawn_and_sleep_forever)
+            async with trio.open_nursery(
+                strict_exception_groups=False,
+            ) as n:
+                await n.start(spawn_and_sleep_forever)
                 if 'mp' in spawn_backend:
                     time.sleep(0.1)
                 os.kill(pid, signal.SIGINT)

tests/test_child_manages_service_nursery.py

@@ -117,10 +117,9 @@ async def open_actor_local_nursery(
     ctx: tractor.Context,
 ):
     global _nursery
-    async with (
-        tractor.trionics.collapse_eg(),
-        trio.open_nursery() as tn
-    ):
+    async with trio.open_nursery(
+        strict_exception_groups=False,
+    ) as tn:
         _nursery = tn
         await ctx.started()
         await trio.sleep(10)

tests/test_discovery.py

@@ -11,7 +11,6 @@ import psutil
 import pytest
 import subprocess
 import tractor
-from tractor.trionics import collapse_eg
 from tractor._testing import tractor_test
 import trio
 
@@ -194,10 +193,10 @@ async def spawn_and_check_registry(
 
             try:
                 async with tractor.open_nursery() as an:
-                    async with (
-                        collapse_eg(),
-                        trio.open_nursery() as trion,
-                    ):
+                    async with trio.open_nursery(
+                        strict_exception_groups=False,
+                    ) as trion:
+
                         portals = {}
                         for i in range(3):
                             name = f'a{i}'
@@ -339,12 +338,11 @@ async def close_chans_before_nursery(
                         async with portal2.open_stream_from(
                             stream_forever
                         ) as agen2:
-                            async with (
-                                collapse_eg(),
-                                trio.open_nursery() as tn,
-                            ):
-                                tn.start_soon(streamer, agen1)
-                                tn.start_soon(cancel, use_signal, .5)
+                            async with trio.open_nursery(
+                                strict_exception_groups=False,
+                            ) as n:
+                                n.start_soon(streamer, agen1)
+                                n.start_soon(cancel, use_signal, .5)
                                 try:
                                     await streamer(agen2)
                                 finally:

tests/test_infected_asyncio.py

@@ -234,8 +234,10 @@ async def trio_ctx(
     with trio.fail_after(1 + delay):
         try:
             async with (
-                tractor.trionics.collapse_eg(),
-                trio.open_nursery() as tn,
+                trio.open_nursery(
+                    # TODO, for new `trio` / py3.13
+                    # strict_exception_groups=False,
+                ) as tn,
                 tractor.to_asyncio.open_channel_from(
                     sleep_and_err,
                 ) as (first, chan),

tests/test_legacy_one_way_streaming.py

@@ -235,16 +235,10 @@ async def cancel_after(wait, reg_addr):
 
 
 @pytest.fixture(scope='module')
-def time_quad_ex(
-    reg_addr: tuple,
-    ci_env: bool,
-    spawn_backend: str,
-):
+def time_quad_ex(reg_addr, ci_env, spawn_backend):
     if spawn_backend == 'mp':
-        '''
-        no idea but the  mp *nix runs are flaking out here often...
-
-        '''
+        """no idea but the  mp *nix runs are flaking out here often...
+        """
         pytest.skip("Test is too flaky on mp in CI")
 
     timeout = 7 if platform.system() in ('Windows', 'Darwin') else 4
@@ -255,24 +249,12 @@ def time_quad_ex(
     return results, diff
 
 
-def test_a_quadruple_example(
-    time_quad_ex: tuple,
-    ci_env: bool,
-    spawn_backend: str,
-):
-    '''
-    This also serves as a kind of "we'd like to be this fast test".
+def test_a_quadruple_example(time_quad_ex, ci_env, spawn_backend):
+    """This also serves as a kind of "we'd like to be this fast test"."""
 
-    '''
     results, diff = time_quad_ex
     assert results
-    this_fast = (
-        6 if platform.system() in (
-            'Windows',
-            'Darwin',
-        )
-        else 3
-    )
+    this_fast = 6 if platform.system() in ('Windows', 'Darwin') else 3
     assert diff < this_fast
 
 

tests/test_trioisms.py

@@ -8,7 +8,6 @@ from contextlib import (
 )
 
 import pytest
-from tractor.trionics import collapse_eg
 import trio
 from trio import TaskStatus
 
@@ -65,8 +64,9 @@ def test_stashed_child_nursery(use_start_soon):
     async def main():
 
         async with (
-            collapse_eg(),
-            trio.open_nursery() as pn,
+            trio.open_nursery(
+                strict_exception_groups=False,
+            ) as pn,
         ):
             cn = await pn.start(mk_child_nursery)
             assert cn
@@ -117,11 +117,9 @@ def test_acm_embedded_nursery_propagates_enter_err(
         async with (
             trio.open_nursery() as tn,
             tractor.trionics.maybe_raise_from_masking_exc(
-                tn=tn,
                 unmask_from=(
-                    trio.Cancelled
-                    if unmask_from_canc
-                    else None
+                    (trio.Cancelled,) if unmask_from_canc
+                    else ()
                 ),
             )
         ):
@@ -136,8 +134,7 @@ def test_acm_embedded_nursery_propagates_enter_err(
         with tractor.devx.maybe_open_crash_handler(
             pdb=debug_mode,
         ) as bxerr:
-            if bxerr:
-                assert not bxerr.value
+            assert not bxerr.value
 
             async with (
                 wraps_tn_that_always_cancels() as tn,
@@ -145,11 +142,12 @@ def test_acm_embedded_nursery_propagates_enter_err(
                 assert not tn.cancel_scope.cancel_called
                 assert 0
 
-        assert (
-            (err := bxerr.value)
-            and
-            type(err) is AssertionError
-        )
+        if debug_mode:
+            assert (
+                (err := bxerr.value)
+                and
+                type(err) is AssertionError
+            )
 
     with pytest.raises(ExceptionGroup) as excinfo:
         trio.run(_main)
@@ -197,8 +195,10 @@ def test_gatherctxs_with_memchan_breaks_multicancelled(
         async with (
             # XXX should ensure ONLY the KBI
             # is relayed upward
-            collapse_eg(),
-            trio.open_nursery(), # as tn,
+            trionics.collapse_eg(),
+            trio.open_nursery(
+                # strict_exception_groups=False,
+            ), # as tn,
 
             trionics.gather_contexts([
                 open_memchan(),

tractor/_root.py

@@ -478,14 +478,16 @@ async def open_root_actor(
 
             # start runtime in a bg sub-task, yield to caller.
             async with (
-                collapse_eg(),
+                collapse_eg(
+                    bp=True,
+                    hide_tb=False,
+                ),
                 trio.open_nursery() as root_tn,
 
-                # ?TODO? finally-footgun below?
+                # XXX, finally-footgun below?
                 # -> see note on why shielding.
                 # maybe_raise_from_masking_exc(),
             ):
-                actor._root_tn = root_tn
                 # `_runtime.async_main()` creates an internal nursery
                 # and blocks here until any underlying actor(-process)
                 # tree has terminated thereby conducting so called
@@ -529,6 +531,7 @@ async def open_root_actor(
                         # crashes under cancellation conditions; so
                         # most of them!
                         shield=root_tn.cancel_scope.cancel_called,
+                        # ^TODO? write a (debugger) test for this ya?
                     )
 
                     if (
@@ -568,7 +571,6 @@ async def open_root_actor(
                         f'{op_nested_actor_repr}'
                     )
                     # XXX, THIS IS A *finally-footgun*!
-                    # (also mentioned in with-block above)
                     # -> though already shields iternally it can
                     # taskc here and mask underlying errors raised in
                     # the try-block above?

tractor/_rpc.py

@@ -284,6 +284,10 @@ async def _errors_relayed_via_ipc(
     try:
         yield  # run RPC invoke body
 
+    except TransportClosed:
+        log.exception('Tpt disconnect during remote-exc relay?')
+        raise
+
     # box and ship RPC errors for wire-transit via
     # the task's requesting parent IPC-channel.
     except (
@@ -319,6 +323,9 @@ async def _errors_relayed_via_ipc(
                         and debug_kbis
                     )
                 )
+                # TODO? better then `debug_filter` below?
+                # and
+                # not isinstance(err, TransportClosed)
             ):
                 # XXX QUESTION XXX: is there any case where we'll
                 # want to debug IPC disconnects as a default?
@@ -327,13 +334,25 @@ async def _errors_relayed_via_ipc(
                 # recovery logic - the only case is some kind of
                 # strange bug in our transport layer itself? Going
                 # to keep this open ended for now.
-                log.debug(
-                    'RPC task crashed, attempting to enter debugger\n'
-                    f'|_{ctx}'
-                )
+
+                if _state.debug_mode():
+                    log.exception(
+                        f'RPC task crashed!\n'
+                        f'Attempting to enter debugger\n'
+                        f'\n'
+                        f'{ctx}'
+                    )
+
                 entered_debug = await debug._maybe_enter_pm(
                     err,
                     api_frame=inspect.currentframe(),
+
+                    # don't REPL any psuedo-expected tpt-disconnect
+                    # debug_filter=lambda exc: (
+                    #     type (exc) not in {
+                    #         TransportClosed,
+                    #     }
+                    # ),
                 )
                 if not entered_debug:
                     # if we prolly should have entered the REPL but
@@ -384,7 +403,7 @@ async def _errors_relayed_via_ipc(
 
     # RPC task bookeeping.
     # since RPC tasks are scheduled inside a flat
-    # `Actor._service_tn`, we add "handles" to each such that
+    # `Actor._service_n`, we add "handles" to each such that
     # they can be individually ccancelled.
     finally:
 
@@ -450,7 +469,7 @@ async def _invoke(
     kwargs: dict[str, Any],
 
     is_rpc: bool = True,
-    hide_tb: bool = True,
+    hide_tb: bool = False,
     return_msg_type: Return|CancelAck = Return,
 
     task_status: TaskStatus[
@@ -462,7 +481,7 @@ async def _invoke(
     connected IPC channel.
 
     This is the core "RPC" `trio.Task` scheduling machinery used to start every
-    remotely invoked function, normally in `Actor._service_tn: Nursery`.
+    remotely invoked function, normally in `Actor._service_n: Nursery`.
 
     '''
     __tracebackhide__: bool = hide_tb
@@ -654,8 +673,7 @@ async def _invoke(
                 # scope ensures unasking of the `await coro` below
                 # *should* never be interfered with!!
                 maybe_raise_from_masking_exc(
-                    tn=tn,
-                    unmask_from=Cancelled,
+                    unmask_from=(Cancelled,),
                 ) as _mbme,  # maybe boxed masked exc
             ):
                 ctx._scope_nursery = tn
@@ -675,7 +693,20 @@ async def _invoke(
                     f'\n'
                     f'{pretty_struct.pformat(return_msg)}\n'
                 )
-                await chan.send(return_msg)
+                try:
+                    await chan.send(return_msg)
+                except TransportClosed:
+                    log.exception(
+                        f"Failed send final result to 'parent'-side of IPC-ctx!\n"
+                        f'\n'
+                        f'{chan}\n'
+                        f'Channel already disconnected ??\n'
+                        f'\n'
+                        f'{pretty_struct.pformat(return_msg)}'
+                    )
+                    # ?TODO? will this ever be true though?
+                    if chan.connected():
+                        raise
 
             # NOTE: this happens IFF `ctx._scope.cancel()` is
             # called by any of,
@@ -936,7 +967,7 @@ async def process_messages(
 
     Receive (multiplexed) per-`Channel` RPC requests as msgs from
     remote processes; schedule target async funcs as local
-    `trio.Task`s inside the `Actor._service_tn: Nursery`.
+    `trio.Task`s inside the `Actor._service_n: Nursery`.
 
     Depending on msg type, non-`cmd` (task spawning/starting)
     request payloads (eg. `started`, `yield`, `return`, `error`)
@@ -961,7 +992,7 @@ async def process_messages(
 
     '''
     actor: Actor = _state.current_actor()
-    assert actor._service_tn  # runtime state sanity
+    assert actor._service_n  # runtime state sanity
 
     # TODO: once `trio` get's an "obvious way" for req/resp we
     # should use it?
@@ -1172,7 +1203,7 @@ async def process_messages(
                         start_status += '->( scheduling new task..\n'
                         log.runtime(start_status)
                         try:
-                            ctx: Context = await actor._service_tn.start(
+                            ctx: Context = await actor._service_n.start(
                                 partial(
                                     _invoke,
                                     actor,
@@ -1312,7 +1343,7 @@ async def process_messages(
     ) as err:
 
         if nursery_cancelled_before_task:
-            sn: Nursery = actor._service_tn
+            sn: Nursery = actor._service_n
             assert sn and sn.cancel_scope.cancel_called  # sanity
             log.cancel(
                 f'Service nursery cancelled before it handled {funcname}'

tractor/_runtime.py

@@ -35,15 +35,6 @@ for running all lower level spawning, supervision and msging layers:
   SC-transitive RPC via scheduling of `trio` tasks.
 - registration of newly spawned actors with the discovery sys.
 
-Glossary:
---------
- - tn: a `trio.Nursery` or "task nursery".
- - an: an `ActorNursery` or "actor nursery".
- - root: top/parent-most scope/task/process/actor (or other runtime
-         primitive) in a hierarchical tree.
- - parent-ish: "higher-up" in the runtime-primitive hierarchy.
- - child-ish: "lower-down" in the runtime-primitive hierarchy.
-
 '''
 from __future__ import annotations
 from contextlib import (
@@ -85,7 +76,6 @@ from tractor.msg import (
 )
 from .trionics import (
     collapse_eg,
-    maybe_open_nursery,
 )
 from .ipc import (
     Channel,
@@ -183,11 +173,9 @@ class Actor:
 
     msg_buffer_size: int = 2**6
 
-    # nursery placeholders filled in by `async_main()`,
-    # - after fork for subactors.
-    # - during boot for the root actor.
-    _root_tn: Nursery|None = None
-    _service_tn: Nursery|None = None
+    # nursery placeholders filled in by `async_main()` after fork
+    _service_n: Nursery|None = None
+
     _ipc_server: _server.IPCServer|None = None
 
     @property
@@ -1021,48 +1009,12 @@ class Actor:
         the RPC service nursery.
 
         '''
-        actor_repr: str = _pformat.nest_from_op(
-            input_op='>c(',
-            text=self.pformat(),
-            nest_indent=1,
-        )
-        log.cancel(
-            'Actor.cancel_soon()` was called!\n'
-            f'>> scheduling `Actor.cancel()`\n'
-            f'{actor_repr}'
-        )
-        assert self._service_tn
-        self._service_tn.start_soon(
+        assert self._service_n
+        self._service_n.start_soon(
             self.cancel,
             None,  # self cancel all rpc tasks
         )
 
-        # schedule a "canceller task" in the `._root_tn` once the
-        # `._service_tn` is fully shutdown; task waits for child-ish
-        # scopes to fully exit then finally cancels its parent,
-        # root-most, scope.
-        async def cancel_root_tn_after_services():
-            log.runtime(
-                'Waiting on service-tn to cancel..\n'
-                f'c>)\n'
-                f'|_{self._service_tn.cancel_scope!r}\n'
-            )
-            await self._cancel_complete.wait()
-            log.cancel(
-                f'`._service_tn` cancelled\n'
-                f'>c)\n'
-                f'|_{self._service_tn.cancel_scope!r}\n'
-                f'\n'
-                f'>> cancelling `._root_tn`\n'
-                f'c>(\n'
-                f' |_{self._root_tn.cancel_scope!r}\n'
-            )
-            self._root_tn.cancel_scope.cancel()
-
-        self._root_tn.start_soon(
-            cancel_root_tn_after_services
-        )
-
     @property
     def cancel_complete(self) -> bool:
         return self._cancel_complete.is_set()
@@ -1167,8 +1119,8 @@ class Actor:
                 await ipc_server.wait_for_shutdown()
 
             # cancel all rpc tasks permanently
-            if self._service_tn:
-                self._service_tn.cancel_scope.cancel()
+            if self._service_n:
+                self._service_n.cancel_scope.cancel()
 
         log_meth(msg)
         self._cancel_complete.set()
@@ -1305,7 +1257,7 @@ class Actor:
         '''
         Cancel all ongoing RPC tasks owned/spawned for a given
         `parent_chan: Channel` or simply all tasks (inside
-        `._service_tn`) when `parent_chan=None`.
+        `._service_n`) when `parent_chan=None`.
 
         '''
         tasks: dict = self._rpc_tasks
@@ -1517,55 +1469,46 @@ async def async_main(
                     accept_addrs.append(addr.unwrap())
 
         assert accept_addrs
-
-        ya_root_tn: bool = bool(actor._root_tn)
-        ya_service_tn: bool = bool(actor._service_tn)
-
-        # NOTE, a top-most "root" nursery in each actor-process
-        # enables a lifetime priority for the IPC-channel connection
-        # with a sub-actor's immediate parent. I.e. this connection
-        # is kept alive as a resilient service connection until all
-        # other machinery has exited, cancellation of all
-        # embedded/child scopes have completed. This helps ensure
-        # a deterministic (and thus "graceful")
-        # first-class-supervision style teardown where a parent actor
-        # (vs. say peers) is always the last to be contacted before
-        # disconnect.
+        # The "root" nursery ensures the channel with the immediate
+        # parent is kept alive as a resilient service until
+        # cancellation steps have (mostly) occurred in
+        # a deterministic way.
         root_tn: trio.Nursery
         async with (
             collapse_eg(),
-            maybe_open_nursery(
-                nursery=actor._root_tn,
-            ) as root_tn,
+            trio.open_nursery() as root_tn,
         ):
-            if ya_root_tn:
-                assert root_tn is actor._root_tn
-            else:
-                actor._root_tn = root_tn
+            # actor._root_n = root_tn
+            # assert actor._root_n
 
             ipc_server: _server.IPCServer
             async with (
                 collapse_eg(),
-                maybe_open_nursery(
-                    nursery=actor._service_tn,
-                ) as service_tn,
+                trio.open_nursery() as service_nursery,
                 _server.open_ipc_server(
-                    parent_tn=service_tn,  # ?TODO, why can't this be the root-tn
-                    stream_handler_tn=service_tn,
+                    parent_tn=service_nursery,
+                    stream_handler_tn=service_nursery,
                 ) as ipc_server,
+                # ) as actor._ipc_server,
+                # ^TODO? prettier?
 
             ):
-                if ya_service_tn:
-                    assert service_tn is actor._service_tn
-                else:
-                    # This nursery is used to handle all inbound
-                    # connections to us such that if the TCP server
-                    # is killed, connections can continue to process
-                    # in the background until this nursery is cancelled.
-                    actor._service_tn = service_tn
-
-                # set after allocate
+                # This nursery is used to handle all inbound
+                # connections to us such that if the TCP server
+                # is killed, connections can continue to process
+                # in the background until this nursery is cancelled.
+                actor._service_n = service_nursery
                 actor._ipc_server = ipc_server
+                assert (
+                    actor._service_n
+                    and (
+                        actor._service_n
+                        is
+                        actor._ipc_server._parent_tn
+                        is
+                        ipc_server._stream_handler_tn
+                    )
+                )
 
                 # load exposed/allowed RPC modules
                 # XXX: do this **after** establishing a channel to the parent
@@ -1591,11 +1534,10 @@ async def async_main(
                 # - root actor: the ``accept_addr`` passed to this method
 
                 # TODO: why is this not with the root nursery?
-                # - see above that the `._service_tn` is what's used?
                 try:
                     eps: list = await ipc_server.listen_on(
                         accept_addrs=accept_addrs,
-                        stream_handler_nursery=service_tn,
+                        stream_handler_nursery=service_nursery,
                     )
                     log.runtime(
                         f'Booted IPC server\n'
@@ -1603,7 +1545,7 @@ async def async_main(
                     )
                     assert (
                         (eps[0].listen_tn)
-                        is not service_tn
+                        is not service_nursery
                     )
 
                 except OSError as oserr:
@@ -1765,7 +1707,7 @@ async def async_main(
 
         # XXX TODO but hard XXX
         # we can't actually do this bc the debugger uses the
-        # _service_tn to spawn the lock task, BUT, in theory if we had
+        # _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?

tractor/_spawn.py

@@ -297,23 +297,6 @@ async def hard_kill(
     # zombies (as a feature) we ask the OS to do send in the
     # removal swad as the last resort.
     if cs.cancelled_caught:
-
-        # TODO? attempt at intermediary-rent-sub
-        # with child in debug lock?
-        # |_https://github.com/goodboy/tractor/issues/320
-        #
-        # if not is_root_process():
-        #     log.warning(
-        #         'Attempting to acquire debug-REPL-lock before zombie reap!'
-        #     )
-        #     with trio.CancelScope(shield=True):
-        #         async with debug.acquire_debug_lock(
-        #             subactor_uid=current_actor().uid,
-        #         ) as _ctx:
-        #             log.warning(
-        #                 'Acquired debug lock, child ready to be killed ??\n'
-        #             )
-
         # TODO: toss in the skynet-logo face as ascii art?
         log.critical(
             # 'Well, the #ZOMBIE_LORD_IS_HERE# to collect\n'

tractor/_supervise.py

@@ -468,7 +468,11 @@ async def _open_and_supervise_one_cancels_all_nursery(
 
     # errors from this daemon actor nursery bubble up to caller
     async with (
-        collapse_eg(),
+        # collapse_eg(),
+        collapse_eg(
+            bp=True,
+            hide_tb=False,
+        ),
         trio.open_nursery() as da_nursery,
     ):
         try:
@@ -481,7 +485,11 @@ async def _open_and_supervise_one_cancels_all_nursery(
             # As such if the strategy propagates any error(s) upwards
             # the above "daemon actor" nursery will be notified.
             async with (
-                collapse_eg(),
+                # collapse_eg(),
+                collapse_eg(
+                    bp=True,
+                    hide_tb=False,
+                ),
                 trio.open_nursery() as ria_nursery,
             ):
                 an = ActorNursery(
@@ -621,11 +629,17 @@ async def _open_and_supervise_one_cancels_all_nursery(
 
                 # use `BaseExceptionGroup` as needed
                 if len(errors) > 1:
-                    raise BaseExceptionGroup(
+                    beg = BaseExceptionGroup(
                         'tractor.ActorNursery errored with',
                         tuple(errors.values()),
                     )
+                    beg.add_note(
+                        'This beg was created from an actor-nursery!\n'
+                    )
+                    await debug.pause(shield=True)
+                    raise beg
                 else:
+                    # await debug.pause(shield=True)
                     raise list(errors.values())[0]
 
             # show frame on any (likely) internal error
@@ -643,9 +657,8 @@ _shutdown_msg: str = (
     'Actor-runtime-shutdown'
 )
 
-
-@acm
 # @api_frame
+@acm
 async def open_nursery(
     *,  # named params only!
     hide_tb: bool = True,
@@ -684,16 +697,30 @@ async def open_nursery(
             # mark us for teardown on exit
             implicit_runtime: bool = True
 
-            async with open_root_actor(
-                hide_tb=hide_tb,
-                **kwargs,
-            ) as actor:
+            async with (
+                # collapse_eg(),
+                collapse_eg(
+                    bp=True,
+                    hide_tb=False,
+                ),
+                open_root_actor(
+                    hide_tb=hide_tb,
+                    **kwargs,
+                ) as actor
+            ):
                 assert actor is current_actor()
 
                 try:
-                    async with _open_and_supervise_one_cancels_all_nursery(
-                        actor
-                    ) as an:
+                    async with (
+                        # collapse_eg(),
+                        collapse_eg(
+                            bp=True,
+                            hide_tb=False,
+                        ),
+                        _open_and_supervise_one_cancels_all_nursery(
+                            actor
+                        ) as an,
+                    ):
 
                         # NOTE: mark this nursery as having
                         # implicitly started the root actor so

tractor/devx/debug/_trace.py

@@ -481,12 +481,12 @@ async def _pause(
             # we have to figure out how to avoid having the service nursery
             # cancel on this task start? I *think* this works below:
             # ```python
-            #   actor._service_tn.cancel_scope.shield = shield
+            #   actor._service_n.cancel_scope.shield = shield
             # ```
             # but not entirely sure if that's a sane way to implement it?
 
             # NOTE currently we spawn the lock request task inside this
-            # subactor's global `Actor._service_tn` so that the
+            # subactor's global `Actor._service_n` so that the
             # lifetime of the lock-request can outlive the current
             # `._pause()` scope while the user steps through their
             # application code and when they finally exit the
@@ -510,7 +510,7 @@ async def _pause(
                 f'|_{task}\n'
             )
             with trio.CancelScope(shield=shield):
-                req_ctx: Context = await actor._service_tn.start(
+                req_ctx: Context = await actor._service_n.start(
                     partial(
                         request_root_stdio_lock,
                         actor_uid=actor.uid,
@@ -544,7 +544,7 @@ async def _pause(
             _repl_fail_report = None
 
         # when the actor is mid-runtime cancellation the
-        # `Actor._service_tn` might get closed before we can spawn
+        # `Actor._service_n` might get closed before we can spawn
         # the request task, so just ignore expected RTE.
         elif (
             isinstance(pause_err, RuntimeError)
@@ -561,6 +561,9 @@ async def _pause(
             return
 
         elif isinstance(pause_err, trio.Cancelled):
+            __tracebackhide__: bool = False
+            # XXX, unmask to REPL it.
+            # mk_pdb().set_trace(frame=inspect.currentframe())
             _repl_fail_report += (
                 'You called `tractor.pause()` from an already cancelled scope!\n\n'
                 'Consider `await tractor.pause(shield=True)` to make it work B)\n'
@@ -989,7 +992,7 @@ def pause_from_sync(
                 # that output and assign the `repl` created above!
                 bg_task, _ = trio.from_thread.run(
                     afn=partial(
-                        actor._service_tn.start,
+                        actor._service_n.start,
                         partial(
                             _pause_from_bg_root_thread,
                             behalf_of_thread=thread,

tractor/ipc/_mp_bs.py

@@ -17,59 +17,36 @@
 Utils to tame mp non-SC madeness
 
 '''
-import platform
-
 
+# !TODO! in 3.13 this can be disabled (the-same/similarly) using
+# a flag,
+# - [ ] soo if it works like this, drop this module entirely for
+#   3.13+ B)
+#  |_https://docs.python.org/3/library/multiprocessing.shared_memory.html
+#
 def disable_mantracker():
     '''
     Disable all `multiprocessing` "resource tracking" machinery since
     it's an absolute multi-threaded mess of non-SC madness.
 
     '''
-    from multiprocessing.shared_memory import SharedMemory
+    from multiprocessing import resource_tracker as mantracker
 
+    # Tell the "resource tracker" thing to fuck off.
+    class ManTracker(mantracker.ResourceTracker):
+        def register(self, name, rtype):
+            pass
 
-    # 3.13+ only.. can pass `track=False` to disable
-    # all the resource tracker bs.
-    # https://docs.python.org/3/library/multiprocessing.shared_memory.html
-    if (_py_313 := (
-            platform.python_version_tuple()[:-1]
-            >=
-            ('3', '13')
-        )
-    ):
-        from functools import partial
-        return partial(
-            SharedMemory,
-            track=False,
-        )
+        def unregister(self, name, rtype):
+            pass
 
-    # !TODO, once we drop 3.12- we can obvi remove all this!
-    else:
-        from multiprocessing import (
-            resource_tracker as mantracker,
-        )
+        def ensure_running(self):
+            pass
 
-        # Tell the "resource tracker" thing to fuck off.
-        class ManTracker(mantracker.ResourceTracker):
-            def register(self, name, rtype):
-                pass
-
-            def unregister(self, name, rtype):
-                pass
-
-            def ensure_running(self):
-                pass
-
-        # "know your land and know your prey"
-        # https://www.dailymotion.com/video/x6ozzco
-        mantracker._resource_tracker = ManTracker()
-        mantracker.register = mantracker._resource_tracker.register
-        mantracker.ensure_running = mantracker._resource_tracker.ensure_running
-        mantracker.unregister = mantracker._resource_tracker.unregister
-        mantracker.getfd = mantracker._resource_tracker.getfd
-
-        # use std type verbatim
-        shmT = SharedMemory
-
-    return shmT
+    # "know your land and know your prey"
+    # https://www.dailymotion.com/video/x6ozzco
+    mantracker._resource_tracker = ManTracker()
+    mantracker.register = mantracker._resource_tracker.register
+    mantracker.ensure_running = mantracker._resource_tracker.ensure_running
+    mantracker.unregister = mantracker._resource_tracker.unregister
+    mantracker.getfd = mantracker._resource_tracker.getfd

tractor/ipc/_server.py

@@ -1001,11 +1001,7 @@ class Server(Struct):
             partial(
                 _serve_ipc_eps,
                 server=self,
-                stream_handler_tn=(
-                    stream_handler_nursery
-                    or
-                    self._stream_handler_tn
-                ),
+                stream_handler_tn=stream_handler_nursery,
                 listen_addrs=accept_addrs,
             )
         )
@@ -1149,17 +1145,13 @@ async def open_ipc_server(
 
     async with maybe_open_nursery(
         nursery=parent_tn,
-    ) as parent_tn:
+    ) as rent_tn:
         no_more_peers = trio.Event()
         no_more_peers.set()
 
         ipc_server = IPCServer(
-            _parent_tn=parent_tn,
-            _stream_handler_tn=(
-                stream_handler_tn
-                or
-                parent_tn
-            ),
+            _parent_tn=rent_tn,
+            _stream_handler_tn=stream_handler_tn or rent_tn,
             _no_more_peers=no_more_peers,
         )
         try:

tractor/ipc/_shm.py

@@ -23,15 +23,14 @@ considered optional within the context of this runtime-library.
 
 """
 from __future__ import annotations
-from multiprocessing import shared_memory as shm
-from multiprocessing.shared_memory import (
-    # SharedMemory,
-    ShareableList,
-)
-import platform
 from sys import byteorder
 import time
 from typing import Optional
+from multiprocessing import shared_memory as shm
+from multiprocessing.shared_memory import (
+    SharedMemory,
+    ShareableList,
+)
 
 from msgspec import (
     Struct,
@@ -62,7 +61,7 @@ except ImportError:
 log = get_logger(__name__)
 
 
-SharedMemory = disable_mantracker()
+disable_mantracker()
 
 
 class SharedInt:
@@ -798,15 +797,8 @@ def open_shm_list(
     # "close" attached shm on actor teardown
     try:
         actor = tractor.current_actor()
-
         actor.lifetime_stack.callback(shml.shm.close)
-
-        # XXX on 3.13+ we don't need to call this?
-        # -> bc we pass `track=False` for `SharedMemeory` orr?
-        if (
-            platform.python_version_tuple()[:-1] < ('3', '13')
-        ):
-            actor.lifetime_stack.callback(shml.shm.unlink)
+        actor.lifetime_stack.callback(shml.shm.unlink)
     except RuntimeError:
         log.warning('tractor runtime not active, skipping teardown steps')
 

tractor/ipc/_transport.py

@@ -430,7 +430,6 @@ class MsgpackTransport(MsgTransport):
                 return await self.stream.send_all(size + bytes_data)
             except (
                 trio.BrokenResourceError,
-                trio.ClosedResourceError,
             ) as _re:
                 trans_err = _re
                 tpt_name: str = f'{type(self).__name__!r}'
@@ -459,22 +458,6 @@ class MsgpackTransport(MsgTransport):
                         )
                         raise tpt_closed from trans_err
 
-                    # case trio.ClosedResourceError() if (
-                    #     'this socket was already closed'
-                    #     in
-                    #     trans_err.args[0]
-                    # ):
-                    #     tpt_closed = TransportClosed.from_src_exc(
-                    #         message=(
-                    #             f'{tpt_name} already closed by peer\n'
-                    #         ),
-                    #         body=f'{self}\n',
-                    #         src_exc=trans_err,
-                    #         raise_on_report=True,
-                    #         loglevel='transport',
-                    #     )
-                    #     raise tpt_closed from trans_err
-
                     # unless the disconnect condition falls under "a
                     # normal operation breakage" we usualy console warn
                     # about it.

tractor/to_asyncio.py

@@ -215,7 +215,7 @@ class LinkedTaskChannel(
         val: Any = None,
     ) -> None:
         '''
-        Synchronize aio-side with its trio-parent.
+        Synchronize aio-sde with its trio-parent.
 
         '''
         self._aio_started_val = val
@@ -459,22 +459,14 @@ def _run_asyncio_task(
                         f'Task exited with final result: {result!r}\n'
                     )
 
-                # XXX ALWAYS close the child-`asyncio`-task-side's
-                # `to_trio` handle which will in turn relay
-                # a `trio.EndOfChannel` to the `trio`-parent.
-                # Consequently the parent `trio` task MUST ALWAYS
-                # check for any `chan._aio_err` to be raised when it
-                # receives an EoC.
-                #
-                # NOTE, there are 2 EoC cases,
-                # - normal/graceful EoC due to the aio-side actually
-                #   terminating its "streaming", but the task did not
-                #   error and is not yet complete.
-                #
-                # - the aio-task terminated and we specially mark the
-                #   closure as due to the `asyncio.Task`'s exit.
+                # only close the aio (child) side which will relay
+                # a `trio.EndOfChannel` to the trio (parent) side.
                 #
+                # XXX NOTE, that trio-side MUST then in such cases
+                # check for a `chan._aio_err` and raise it!!
                 to_trio.close()
+                # specially mark the closure as due to the
+                # asyncio.Task terminating!
                 chan._closed_by_aio_task = True
 
             aio_task_complete.set()
@@ -854,6 +846,8 @@ async def translate_aio_errors(
             chan._trio_to_raise = aio_err
             trio_err = chan._trio_err = eoc
             #
+            # await tractor.pause(shield=True)
+            #
             # ?TODO?, raise something like a,
             # chan._trio_to_raise = AsyncioErrored()
             # BUT, with the tb rewritten to reflect the underlying

tractor/trionics/_mngrs.py

@@ -204,7 +204,7 @@ class _Cache:
     a kept-alive-while-in-use async resource.
 
     '''
-    service_tn: Optional[trio.Nursery] = None
+    service_n: Optional[trio.Nursery] = None
     locks: dict[Hashable, trio.Lock] = {}
     users: int = 0
     values: dict[Any,  Any] = {}
@@ -223,16 +223,18 @@ class _Cache:
         task_status: trio.TaskStatus[T] = trio.TASK_STATUS_IGNORED,
 
     ) -> None:
-        async with mng as value:
-            _, no_more_users = cls.resources[ctx_key]
-            cls.values[ctx_key] = value
-            task_status.started(value)
-            try:
-                await no_more_users.wait()
-            finally:
-                # discard nursery ref so it won't be re-used (an error)?
-                value = cls.values.pop(ctx_key)
-                cls.resources.pop(ctx_key)
+        try:
+            async with mng as value:
+                _, no_more_users = cls.resources[ctx_key]
+                try:
+                    cls.values[ctx_key] = value
+                    task_status.started(value)
+                    await no_more_users.wait()
+                finally:
+                    value = cls.values.pop(ctx_key)
+        finally:
+            # discard nursery ref so it won't be re-used (an error)?
+            cls.resources.pop(ctx_key)
 
 
 @acm
@@ -294,15 +296,15 @@ async def maybe_open_context(
                 f'task: {task}\n'
                 f'task_tn: {task_tn}\n'
             )
-        service_tn = tn
+        service_n = tn
     else:
-        service_tn: trio.Nursery = current_actor()._service_tn
+        service_n: trio.Nursery = current_actor()._service_n
 
     # TODO: is there any way to allocate
     # a 'stays-open-till-last-task-finshed nursery?
-    # service_tn: trio.Nursery
-    # async with maybe_open_nursery(_Cache.service_tn) as service_tn:
-    #     _Cache.service_tn = service_tn
+    # service_n: trio.Nursery
+    # async with maybe_open_nursery(_Cache.service_n) as service_n:
+    #     _Cache.service_n = service_n
 
     cache_miss_ke: KeyError|None = None
     maybe_taskc: trio.Cancelled|None = None
@@ -324,8 +326,8 @@ async def maybe_open_context(
             mngr = acm_func(**kwargs)
             resources = _Cache.resources
             assert not resources.get(ctx_key), f'Resource exists? {ctx_key}'
-            resources[ctx_key] = (service_tn, trio.Event())
-            yielded: Any = await service_tn.start(
+            resources[ctx_key] = (service_n, trio.Event())
+            yielded: Any = await service_n.start(
                 _Cache.run_ctx,
                 mngr,
                 ctx_key,

tractor/trionics/_taskc.py

@@ -22,7 +22,10 @@ from __future__ import annotations
 from contextlib import (
     asynccontextmanager as acm,
 )
-from typing import TYPE_CHECKING
+from typing import (
+    Type,
+    TYPE_CHECKING,
+)
 
 import trio
 from tractor.log import get_logger
@@ -65,7 +68,6 @@ def find_masked_excs(
 #
 @acm
 async def maybe_raise_from_masking_exc(
-    tn: trio.Nursery|None = None,
     unmask_from: (
         BaseException|
         tuple[BaseException]
@@ -74,15 +76,26 @@ async def maybe_raise_from_masking_exc(
     raise_unmasked: bool = True,
     extra_note: str = (
         'This can occurr when,\n'
-        ' - a `trio.Nursery` scope embeds a `finally:`-block '
-        'which executes a checkpoint!'
+        '\n'
+        ' - a `trio.Nursery/CancelScope` embeds a `finally/except:`-block '
+        'which execs an un-shielded checkpoint!'
         #
         # ^TODO? other cases?
     ),
 
-    always_warn_on: tuple[BaseException] = (
+    always_warn_on: tuple[Type[BaseException]] = (
         trio.Cancelled,
     ),
+
+    # don't ever unmask or warn on any masking pair,
+    # {<masked-excT-key> -> <masking-excT-value>}
+    never_warn_on: dict[
+        Type[BaseException],
+        Type[BaseException],
+    ] = {
+        KeyboardInterrupt: trio.Cancelled,
+        trio.Cancelled: trio.Cancelled,
+    },
     # ^XXX, special case(s) where we warn-log bc likely
     # there will be no operational diff since the exc
     # is always expected to be consumed.
@@ -104,81 +117,91 @@ async def maybe_raise_from_masking_exc(
         individual sub-excs but maintain the eg-parent's form right?
 
     '''
+    if not isinstance(unmask_from, tuple):
+        raise ValueError(
+            f'Invalid unmask_from = {unmask_from!r}\n'
+            f'Must be a `tuple[Type[BaseException]]`.\n'
+        )
+
     from tractor.devx.debug import (
         BoxedMaybeException,
-        pause,
     )
     boxed_maybe_exc = BoxedMaybeException(
         raise_on_exit=raise_unmasked,
     )
     matching: list[BaseException]|None = None
-    maybe_eg: ExceptionGroup|None
-
-    if tn:
-        try:  # handle egs
-            yield boxed_maybe_exc
-            return
-        except* unmask_from as _maybe_eg:
-            maybe_eg = _maybe_eg
+    try:
+        yield boxed_maybe_exc
+        return
+    except BaseException as _bexc:
+        bexc = _bexc
+        if isinstance(bexc, BaseExceptionGroup):
             matches: ExceptionGroup
-            matches, _ = maybe_eg.split(
-                unmask_from
-            )
-            if not matches:
-                raise
+            matches, _ = bexc.split(unmask_from)
+            if matches:
+                matching = matches.exceptions
 
-            matching: list[BaseException] = matches.exceptions
-    else:
-        try:  # handle non-egs
-            yield boxed_maybe_exc
-            return
-        except unmask_from as _maybe_exc:
-            maybe_exc = _maybe_exc
-            matching: list[BaseException] = [
-                maybe_exc
-            ]
-
-        # XXX, only unmask-ed for debuggin!
-        # TODO, remove eventually..
-        except BaseException as _berr:
-            berr = _berr
-            await pause(shield=True)
-            raise berr
+        elif (
+            unmask_from
+            and
+            type(bexc) in unmask_from
+        ):
+            matching = [bexc]
 
     if matching is None:
         raise
 
     masked: list[tuple[BaseException, BaseException]] = []
     for exc_match in matching:
-
         if exc_ctx := find_masked_excs(
             maybe_masker=exc_match,
-            unmask_from={unmask_from},
+            unmask_from=set(unmask_from),
         ):
-            masked.append((exc_ctx, exc_match))
+            masked.append((
+                exc_ctx,
+                exc_match,
+            ))
             boxed_maybe_exc.value = exc_match
             note: str = (
                 f'\n'
-                f'^^WARNING^^ the above {exc_ctx!r} was masked by a {unmask_from!r}\n'
+                f'^^WARNING^^\n'
+                f'the above {type(exc_ctx)!r} was masked by a {type(exc_match)!r}\n'
             )
             if extra_note:
                 note += (
                     f'\n'
                     f'{extra_note}\n'
                 )
-            exc_ctx.add_note(note)
 
-            if type(exc_match) in always_warn_on:
+            do_warn: bool = (
+                never_warn_on.get(
+                    type(exc_ctx)  # masking type
+                )
+                is not
+                type(exc_match)  # masked type
+            )
+
+            if do_warn:
+                exc_ctx.add_note(note)
+
+            if (
+                do_warn
+                and
+                type(exc_match) in always_warn_on
+            ):
                 log.warning(note)
 
-            # await tractor.pause(shield=True)
-            if raise_unmasked:
-
+            if (
+                do_warn
+                and
+                raise_unmasked
+            ):
                 if len(masked) < 2:
                     raise exc_ctx from exc_match
-                else:
-                    # ?TODO, see above but, possibly unmasking sub-exc
-                    # entries if there are > 1
-                    await pause(shield=True)
+
+                # ??TODO, see above but, possibly unmasking sub-exc
+                # entries if there are > 1
+                # else:
+                #     await pause(shield=True)
     else:
         raise