Bump "task-manager(-nursery)" naming, add logging

Namely just renaming any `trio.Nursery` instances to `tn`, the primary
`@acm`-API to `.trionics.open_taskman()` and change out all `print()`s
for logger instances with 'info' level enabled by the mod-script usage.

examples/debugging/fast_error_in_root_after_spawn.py

@@ -20,7 +20,7 @@ async def sleep(
 
 
 async def open_ctx(
-    n: tractor._supervise.ActorNursery
+    n: tractor.runtime._supervise.ActorNursery
 ):
 
     # spawn both actors

examples/service_discovery.py

@@ -10,7 +10,7 @@ async def main(service_name):
         await an.start_actor(service_name)
 
         async with tractor.get_registry() as portal:
-            print(f"Arbiter is listening on {portal.channel}")
+            print(f"Registrar is listening on {portal.channel}")
 
         async with tractor.wait_for_actor(service_name) as sockaddr:
             print(f"my_service is found at {sockaddr}")

tests/conftest.py

@@ -9,6 +9,8 @@ import os
 import signal
 import platform
 import time
+from pathlib import Path
+from typing import Literal
 
 import pytest
 import tractor
@@ -52,6 +54,76 @@ no_macos = pytest.mark.skipif(
 )
 
 
+def get_cpu_state(
+    icpu: int = 0,
+    setting: Literal[
+        'scaling_governor',
+        '*_pstate_max_freq',
+        'scaling_max_freq',
+        # 'scaling_cur_freq',
+    ] = '*_pstate_max_freq',
+) -> tuple[
+    Path,
+    str|int,
+]|None:
+    '''
+    Attempt to read the (first) CPU's setting according
+    to the set `setting` from under the file-sys,
+
+    /sys/devices/system/cpu/cpu0/cpufreq/{setting}
+
+    Useful to determine latency headroom for various perf affected
+    test suites.
+
+    '''
+    try:
+        # Read governor for core 0 (usually same for all)
+        setting_path: Path = list(
+            Path(f'/sys/devices/system/cpu/cpu{icpu}/cpufreq/')
+            .glob(f'{setting}')
+        )[0]  # <- XXX must be single match!
+        with open(
+            setting_path,
+            'r',
+        ) as f:
+            return (
+                setting_path,
+                f.read().strip(),
+            )
+    except (FileNotFoundError, IndexError):
+        return None
+
+
+def cpu_scaling_factor() -> float:
+    '''
+    Return a latency-headroom multiplier (>= 1.0) reflecting how
+    much to inflate time-limits when CPU-freq scaling is active on
+    linux.
+
+    When no scaling info is available (non-linux, missing sysfs),
+    returns 1.0 (i.e. no headroom adjustment needed).
+
+    '''
+    if _non_linux:
+        return 1.
+
+    mx = get_cpu_state()
+    cur = get_cpu_state(setting='scaling_max_freq')
+    if mx is None or cur is None:
+        return 1.
+
+    _mx_pth, max_freq = mx
+    _cur_pth, cur_freq = cur
+    cpu_scaled: float = int(cur_freq) / int(max_freq)
+
+    if cpu_scaled != 1.:
+        return 1. / (
+            cpu_scaled * 2  # <- bc likely "dual threaded"
+        )
+
+    return 1.
+
+
 def pytest_addoption(
     parser: pytest.Parser,
 ):

tests/devx/test_tooling.py

@@ -126,7 +126,7 @@ def test_shield_pause(
         child.pid,
         signal.SIGINT,
     )
-    from tractor._supervise import _shutdown_msg
+    from tractor.runtime._supervise import _shutdown_msg
     expect(
         child,
         # 'Shutting down actor runtime',

tests/ipc/test_each_tpt.py

@@ -8,17 +8,16 @@ from pathlib import Path
 import pytest
 import trio
 import tractor
-from tractor import (
-    Actor,
-    _state,
-    _addr,
-)
+from tractor import Actor
+from tractor.runtime import _state
+from tractor.discovery import _addr
 
 
 @pytest.fixture
 def bindspace_dir_str() -> str:
 
-    rt_dir: Path = tractor._state.get_rt_dir()
+    from tractor.runtime._state import get_rt_dir
+    rt_dir: Path = get_rt_dir()
     bs_dir: Path = rt_dir / 'doggy'
     bs_dir_str: str = str(bs_dir)
     assert not bs_dir.is_dir()

tests/ipc/test_multi_tpt.py

@@ -13,9 +13,9 @@ from tractor import (
     Portal,
     ipc,
     msg,
-    _state,
-    _addr,
 )
+from tractor.runtime import _state
+from tractor.discovery import _addr
 
 @tractor.context
 async def chk_tpts(

tests/msg/test_pldrx_limiting.py

@@ -61,7 +61,7 @@ async def maybe_expect_raises(
     Async wrapper for ensuring errors propagate from the inner scope.
 
     '''
-    if tractor._state.debug_mode():
+    if tractor.debug_mode():
         timeout += 999
 
     with trio.fail_after(timeout):

tests/test_cancellation.py

@@ -490,7 +490,7 @@ def test_cancel_via_SIGINT(
     """Ensure that a control-C (SIGINT) signal cancels both the parent and
     child processes in trionic fashion
     """
-    pid = os.getpid()
+    pid: int = os.getpid()
 
     async def main():
         with trio.fail_after(2):
@@ -517,6 +517,8 @@ def test_cancel_via_SIGINT_other_task(
     started from a seperate ``trio`` child  task.
 
     '''
+    from .conftest import cpu_scaling_factor
+
     pid: int = os.getpid()
     timeout: float = (
         4 if _non_linux
@@ -525,6 +527,11 @@ def test_cancel_via_SIGINT_other_task(
     if _friggin_windows:  # smh
         timeout += 1
 
+    # add latency headroom for CPU freq scaling (auto-cpufreq et al.)
+    headroom: float = cpu_scaling_factor()
+    if headroom != 1.:
+        timeout *= headroom
+
     async def spawn_and_sleep_forever(
         task_status=trio.TASK_STATUS_IGNORED
     ):

tests/test_clustering.py

@@ -10,7 +10,20 @@ from tractor._testing import tractor_test
 MESSAGE = 'tractoring at full speed'
 
 
-def test_empty_mngrs_input_raises() -> None:
+def test_empty_mngrs_input_raises(
+    tpt_proto: str,
+) -> None:
+    # TODO, the `open_actor_cluster()` teardown hangs
+    # intermittently on UDS when `gather_contexts(mngrs=())`
+    # raises `ValueError` mid-setup; likely a race in the
+    # actor-nursery cleanup vs UDS socket shutdown. Needs
+    # a deeper look at `._clustering`/`._supervise` teardown
+    # paths with the UDS transport.
+    if tpt_proto == 'uds':
+        pytest.skip(
+            'actor-cluster teardown hangs intermittently on UDS'
+        )
+
     async def main():
         with trio.fail_after(3):
             async with (

tests/test_context_stream_semantics.py

@@ -26,7 +26,7 @@ from tractor._exceptions import (
     StreamOverrun,
     ContextCancelled,
 )
-from tractor._state import current_ipc_ctx
+from tractor.runtime._state import current_ipc_ctx
 
 from tractor._testing import (
     tractor_test,
@@ -939,7 +939,7 @@ def test_one_end_stream_not_opened(
 
     '''
     overrunner, buf_size_increase, entrypoint = overrun_by
-    from tractor._runtime import Actor
+    from tractor.runtime._runtime import Actor
     buf_size = buf_size_increase + Actor.msg_buffer_size
 
     timeout: float = (

tests/test_discovery.py

@@ -1,7 +1,7 @@
-"""
-Discovery subsys.
+'''
+Discovery subsystem via a "registrar" actor scenarios.
 
-"""
+'''
 import os
 import signal
 import platform
@@ -24,7 +24,7 @@ async def test_reg_then_unreg(
     reg_addr: tuple,
 ):
     actor = tractor.current_actor()
-    assert actor.is_arbiter
+    assert actor.is_registrar
     assert len(actor._registry) == 1  # only self is registered
 
     async with tractor.open_nursery(
@@ -35,7 +35,7 @@ async def test_reg_then_unreg(
         uid = portal.channel.aid.uid
 
         async with tractor.get_registry(reg_addr) as aportal:
-            # this local actor should be the arbiter
+            # this local actor should be the registrar
             assert actor is aportal.actor
 
             async with tractor.wait_for_actor('actor'):
@@ -154,7 +154,7 @@ async def unpack_reg(
     actor_or_portal: tractor.Portal|tractor.Actor,
 ):
     '''
-    Get and unpack a "registry" RPC request from the "arbiter" registry
+    Get and unpack a "registry" RPC request from the registrar
     system.
 
     '''
@@ -163,7 +163,10 @@ async def unpack_reg(
     else:
         msg = await actor_or_portal.run_from_ns('self', 'get_registry')
 
-    return {tuple(key.split('.')): val for key, val in msg.items()}
+    return {
+        tuple(key.split('.')): val
+        for key, val in msg.items()
+    }
 
 
 async def spawn_and_check_registry(
@@ -194,15 +197,15 @@ async def spawn_and_check_registry(
             actor = tractor.current_actor()
 
             if remote_arbiter:
-                assert not actor.is_arbiter
+                assert not actor.is_registrar
 
-            if actor.is_arbiter:
-                extra = 1  # arbiter is local root actor
+            if actor.is_registrar:
+                extra = 1  # registrar is local root actor
                 get_reg = partial(unpack_reg, actor)
 
             else:
                 get_reg = partial(unpack_reg, portal)
-                extra = 2  # local root actor + remote arbiter
+                extra = 2  # local root actor + remote registrar
 
             # ensure current actor is registered
             registry: dict = await get_reg()
@@ -282,7 +285,7 @@ def test_subactors_unregister_on_cancel(
 ):
     '''
     Verify that cancelling a nursery results in all subactors
-    deregistering themselves with the arbiter.
+    deregistering themselves with the registrar.
 
     '''
     with pytest.raises(KeyboardInterrupt):
@@ -311,7 +314,7 @@ def test_subactors_unregister_on_cancel_remote_daemon(
     '''
     Verify that cancelling a nursery results in all subactors
     deregistering themselves with a **remote** (not in the local
-    process tree) arbiter.
+    process tree) registrar.
 
     '''
     with pytest.raises(KeyboardInterrupt):
@@ -356,20 +359,24 @@ async def close_chans_before_nursery(
             try:
                 get_reg = partial(unpack_reg, aportal)
 
-                async with tractor.open_nursery() as tn:
-                    portal1 = await tn.start_actor(
-                        name='consumer1', enable_modules=[__name__])
-                    portal2 = await tn.start_actor(
-                        'consumer2', enable_modules=[__name__])
+                async with tractor.open_nursery() as an:
+                    portal1 = await an.start_actor(
+                        name='consumer1',
+                        enable_modules=[__name__],
+                    )
+                    portal2 = await an.start_actor(
+                        'consumer2',
+                        enable_modules=[__name__],
+                    )
 
-                    # TODO: compact this back as was in last commit once
-                    # 3.9+, see https://github.com/goodboy/tractor/issues/207
-                    async with portal1.open_stream_from(
-                        stream_forever
-                    ) as agen1:
-                        async with portal2.open_stream_from(
+                    async with (
+                        portal1.open_stream_from(
                             stream_forever
-                        ) as agen2:
+                        ) as agen1,
+                        portal2.open_stream_from(
+                            stream_forever
+                        ) as agen2,
+                    ):
                             async with (
                                 collapse_eg(),
                                 trio.open_nursery() as tn,
@@ -380,7 +387,7 @@ async def close_chans_before_nursery(
                                     await streamer(agen2)
                                 finally:
                                     # Kill the root nursery thus resulting in
-                                    # normal arbiter channel ops to fail during
+                                    # normal registrar channel ops to fail during
                                     # teardown. It doesn't seem like this is
                                     # reliably triggered by an external SIGINT.
                                     # tractor.current_actor()._root_nursery.cancel_scope.cancel()
@@ -392,6 +399,7 @@ async def close_chans_before_nursery(
                                     # also kill off channels cuz why not
                                     await agen1.aclose()
                                     await agen2.aclose()
+
             finally:
                 with trio.CancelScope(shield=True):
                     await trio.sleep(1)
@@ -412,7 +420,7 @@ def test_close_channel_explicit(
     '''
     Verify that closing a stream explicitly and killing the actor's
     "root nursery" **before** the containing nursery tears down also
-    results in subactor(s) deregistering from the arbiter.
+    results in subactor(s) deregistering from the registrar.
 
     '''
     with pytest.raises(KeyboardInterrupt):
@@ -427,7 +435,7 @@ def test_close_channel_explicit(
 
 
 @pytest.mark.parametrize('use_signal', [False, True])
-def test_close_channel_explicit_remote_arbiter(
+def test_close_channel_explicit_remote_registrar(
     daemon: subprocess.Popen,
     start_method: str,
     use_signal: bool,
@@ -436,7 +444,7 @@ def test_close_channel_explicit_remote_arbiter(
     '''
     Verify that closing a stream explicitly and killing the actor's
     "root nursery" **before** the containing nursery tears down also
-    results in subactor(s) deregistering from the arbiter.
+    results in subactor(s) deregistering from the registrar.
 
     '''
     with pytest.raises(KeyboardInterrupt):
@@ -448,3 +456,65 @@ def test_close_channel_explicit_remote_arbiter(
                 remote_arbiter=True,
             ),
         )
+
+
+@tractor.context
+async def kill_transport(
+    ctx: tractor.Context,
+) -> None:
+
+    await ctx.started()
+    actor: tractor.Actor = tractor.current_actor()
+    actor.ipc_server.cancel()
+    await trio.sleep_forever()
+
+
+
+# @pytest.mark.parametrize('use_signal', [False, True])
+def test_stale_entry_is_deleted(
+    debug_mode: bool,
+    daemon: subprocess.Popen,
+    start_method: str,
+    reg_addr: tuple,
+):
+    '''
+    Ensure that when a stale entry is detected in the registrar's
+    table that the `find_actor()` API takes care of deleting the
+    stale entry and not delivering a bad portal.
+
+    '''
+    async def main():
+
+        name: str = 'transport_fails_actor'
+        _reg_ptl: tractor.Portal
+        an: tractor.ActorNursery
+        async with (
+            tractor.open_nursery(
+                debug_mode=debug_mode,
+                registry_addrs=[reg_addr],
+            ) as an,
+            tractor.get_registry(reg_addr) as _reg_ptl,
+        ):
+            ptl: tractor.Portal = await an.start_actor(
+                name,
+                enable_modules=[__name__],
+            )
+            async with ptl.open_context(
+                kill_transport,
+            ) as (first, ctx):
+                async with tractor.find_actor(
+                    name,
+                    registry_addrs=[reg_addr],
+                ) as maybe_portal:
+                    # because the transitive
+                    # `._discovery.maybe_open_portal()` call should
+                    # fail and implicitly call `.delete_addr()`
+                    assert maybe_portal is None
+                    registry: dict = await unpack_reg(_reg_ptl)
+                    assert ptl.chan.aid.uid not in registry
+
+                # should fail since we knocked out the IPC tpt XD
+                await ptl.cancel_actor()
+                await an.cancel()
+
+    trio.run(main)

tests/test_docs_examples.py

@@ -94,8 +94,10 @@ def run_example_in_subproc(
         for f in p[2]
 
         if (
-            '__' not in f
-            and f[0] != '_'
+            '__' not in f  # ignore any pkg-mods
+            # ignore any `__pycache__` subdir
+            and '__pycache__' not in str(p[0])
+            and f[0] != '_'  # ignore any WIP "examplel mods"
             and 'debugging' not in p[0]
             and 'integration' not in p[0]
             and 'advanced_faults' not in p[0]
@@ -143,12 +145,19 @@ def test_example(
             'This test does run just fine "in person" however..'
         )
 
+    from .conftest import cpu_scaling_factor
+
     timeout: float = (
         60
         if ci_env and _non_linux
         else 16
     )
 
+    # add latency headroom for CPU freq scaling (auto-cpufreq et al.)
+    headroom: float = cpu_scaling_factor()
+    if headroom != 1.:
+        timeout *= headroom
+
     with open(ex_file, 'r') as ex:
         code = ex.read()
 

tests/test_infected_asyncio.py

@@ -26,8 +26,8 @@ from tractor import (
     to_asyncio,
     RemoteActorError,
     ContextCancelled,
-    _state,
 )
+from tractor.runtime import _state
 from tractor.trionics import BroadcastReceiver
 from tractor._testing import expect_ctxc
 

tests/test_inter_peer_cancellation.py

@@ -201,7 +201,7 @@ async def stream_from_peer(
 ) -> None:
 
     # sanity
-    assert tractor._state.debug_mode() == debug_mode
+    assert tractor.debug_mode() == debug_mode
 
     peer: Portal
     try:
@@ -841,7 +841,7 @@ async def serve_subactors(
     async with open_nursery() as an:
 
         # sanity
-        assert tractor._state.debug_mode() == debug_mode
+        assert tractor.debug_mode() == debug_mode
 
         await ctx.started(peer_name)
         async with ctx.open_stream() as ipc:
@@ -880,7 +880,7 @@ async def client_req_subactor(
 ) -> None:
     # sanity
     if debug_mode:
-        assert tractor._state.debug_mode()
+        assert tractor.debug_mode()
 
     # TODO: other cases to do with sub lifetimes:
     # -[ ] test that we can have the server spawn a sub

tests/test_legacy_one_way_streaming.py

@@ -300,19 +300,43 @@ def test_a_quadruple_example(
     time_quad_ex: tuple[list[int], float],
     ci_env: bool,
     spawn_backend: str,
+    test_log: tractor.log.StackLevelAdapter,
 ):
     '''
-    This also serves as a kind of "we'd like to be this fast test".
+    This also serves as a "we'd like to be this fast" smoke test
+    given past empirical eval of this suite.
 
     '''
     non_linux: bool = (_sys := platform.system()) != 'Linux'
 
-    results, diff = time_quad_ex
-    assert results
+    this_fast_on_linux: float = 3
     this_fast = (
         6 if non_linux
-        else 3
+        else this_fast_on_linux
     )
+    # ^ XXX NOTE,
+    # i've noticed that tweaking the CPU governor setting
+    # to not "always" enable "turbo" mode can result in latency
+    # which causes this limit to be too little. Not sure if it'd
+    # be worth it to adjust the linux value based on reading the
+    # CPU conf from the sys?
+    #
+    # For ex, see the `auto-cpufreq` docs on such settings,
+    # https://github.com/AdnanHodzic/auto-cpufreq?tab=readme-ov-file#example-config-file-contents
+    #
+    # HENCE this below latency-headroom compensation logic..
+    from .conftest import cpu_scaling_factor
+    headroom: float = cpu_scaling_factor()
+    if headroom != 1.:
+        this_fast = this_fast_on_linux * headroom
+        test_log.warning(
+            f'Adding latency headroom on linux bc CPU scaling,\n'
+            f'headroom: {headroom}\n'
+            f'this_fast_on_linux: {this_fast_on_linux} -> {this_fast}\n'
+        )
+
+    results, diff = time_quad_ex
+    assert results
     assert diff < this_fast
 
 
@@ -353,7 +377,7 @@ def test_not_fast_enough_quad(
         assert results is None
 
 
-@tractor_test
+@tractor_test(timeout=20)
 async def test_respawn_consumer_task(
     reg_addr: tuple,
     spawn_backend: str,

tests/test_local.py

@@ -1,5 +1,5 @@
 """
-Arbiter and "local" actor api
+Registrar and "local" actor api
 """
 import time
 
@@ -12,11 +12,11 @@ from tractor._testing import tractor_test
 
 @pytest.mark.trio
 async def test_no_runtime():
-    """An arbitter must be established before any nurseries
+    """A registrar must be established before any nurseries
     can be created.
 
-    (In other words ``tractor.open_root_actor()`` must be engaged at
-    some point?)
+    (In other words ``tractor.open_root_actor()`` must be
+    engaged at some point?)
     """
     with pytest.raises(RuntimeError) :
         async with tractor.find_actor('doggy'):
@@ -25,9 +25,9 @@ async def test_no_runtime():
 
 @tractor_test
 async def test_self_is_registered(reg_addr):
-    "Verify waiting on the arbiter to register itself using the standard api."
+    "Verify waiting on the registrar to register itself using the standard api."
     actor = tractor.current_actor()
-    assert actor.is_arbiter
+    assert actor.is_registrar
     with trio.fail_after(0.2):
         async with tractor.wait_for_actor('root') as portal:
             assert portal.channel.uid[0] == 'root'
@@ -35,11 +35,11 @@ async def test_self_is_registered(reg_addr):
 
 @tractor_test
 async def test_self_is_registered_localportal(reg_addr):
-    "Verify waiting on the arbiter to register itself using a local portal."
+    "Verify waiting on the registrar to register itself using a local portal."
     actor = tractor.current_actor()
-    assert actor.is_arbiter
+    assert actor.is_registrar
     async with tractor.get_registry(reg_addr) as portal:
-        assert isinstance(portal, tractor._portal.LocalPortal)
+        assert isinstance(portal, tractor.runtime._portal.LocalPortal)
 
         with trio.fail_after(0.2):
             sockaddr = await portal.run_from_ns(
@@ -57,8 +57,8 @@ def test_local_actor_async_func(reg_addr):
         async with tractor.open_root_actor(
             registry_addrs=[reg_addr],
         ):
-            # arbiter is started in-proc if dne
-            assert tractor.current_actor().is_arbiter
+            # registrar is started in-proc if dne
+            assert tractor.current_actor().is_registrar
 
             for i in range(10):
                 nums.append(i)

tests/test_multi_program.py

@@ -17,11 +17,11 @@ from tractor._testing import (
 )
 from tractor import (
     current_actor,
-    _state,
     Actor,
     Context,
     Portal,
 )
+from tractor.runtime import _state
 from .conftest import (
     sig_prog,
     _INT_SIGNAL,
@@ -30,7 +30,7 @@ from .conftest import (
 
 if TYPE_CHECKING:
     from tractor.msg import Aid
-    from tractor._addr import (
+    from tractor.discovery._addr import (
         UnwrappedAddress,
     )
 
@@ -53,19 +53,19 @@ def test_abort_on_sigint(
 
 
 @tractor_test
-async def test_cancel_remote_arbiter(
+async def test_cancel_remote_registrar(
     daemon: subprocess.Popen,
     reg_addr: UnwrappedAddress,
 ):
-    assert not current_actor().is_arbiter
+    assert not current_actor().is_registrar
     async with tractor.get_registry(reg_addr) as portal:
         await portal.cancel_actor()
 
     time.sleep(0.1)
-    # the arbiter channel server is cancelled but not its main task
+    # the registrar channel server is cancelled but not its main task
     assert daemon.returncode is None
 
-    # no arbiter socket should exist
+    # no registrar socket should exist
     with pytest.raises(OSError):
         async with tractor.get_registry(reg_addr) as portal:
             pass
@@ -80,7 +80,7 @@ def test_register_duplicate_name(
             registry_addrs=[reg_addr],
         ) as an:
 
-            assert not current_actor().is_arbiter
+            assert not current_actor().is_registrar
 
             p1 = await an.start_actor('doggy')
             p2 = await an.start_actor('doggy')
@@ -122,7 +122,7 @@ async def get_root_portal(
 
     # connect back to our immediate parent which should also
     # be the actor-tree's root.
-    from tractor._discovery import get_root
+    from tractor.discovery._discovery import get_root
     ptl: Portal
     async with get_root() as ptl:
         root_aid: Aid = ptl.chan.aid

tests/test_reg_err_types.py

@@ -0,0 +1,333 @@
+'''
+Verify that externally registered remote actor error
+types are correctly relayed, boxed, and re-raised across
+IPC actor hops via `reg_err_types()`.
+
+Also ensure that when custom error types are NOT registered
+the framework indicates the lookup failure to the user.
+
+'''
+import pytest
+import trio
+import tractor
+from tractor import (
+    Context,
+    Portal,
+    RemoteActorError,
+)
+from tractor._exceptions import (
+    get_err_type,
+    reg_err_types,
+)
+
+
+# -- custom app-level errors for testing --
+class CustomAppError(Exception):
+    '''
+    A hypothetical user-app error that should be
+    boxed+relayed by `tractor` IPC when registered.
+
+    '''
+
+
+class AnotherAppError(Exception):
+    '''
+    A second custom error for multi-type registration.
+
+    '''
+
+
+class UnregisteredAppError(Exception):
+    '''
+    A custom error that is intentionally NEVER
+    registered via `reg_err_types()` so we can
+    verify the framework's failure indication.
+
+    '''
+
+
+# -- remote-task endpoints --
+@tractor.context
+async def raise_custom_err(
+    ctx: Context,
+) -> None:
+    '''
+    Remote ep that raises a `CustomAppError`
+    after sync-ing with the caller.
+
+    '''
+    await ctx.started()
+    raise CustomAppError(
+        'the app exploded remotely'
+    )
+
+
+@tractor.context
+async def raise_another_err(
+    ctx: Context,
+) -> None:
+    '''
+    Remote ep that raises `AnotherAppError`.
+
+    '''
+    await ctx.started()
+    raise AnotherAppError(
+        'another app-level kaboom'
+    )
+
+
+@tractor.context
+async def raise_unreg_err(
+    ctx: Context,
+) -> None:
+    '''
+    Remote ep that raises an `UnregisteredAppError`
+    which has NOT been `reg_err_types()`-registered.
+
+    '''
+    await ctx.started()
+    raise UnregisteredAppError(
+        'this error type is unknown to tractor'
+    )
+
+
+# -- unit tests for the type-registry plumbing --
+
+class TestRegErrTypesPlumbing:
+    '''
+    Low-level checks on `reg_err_types()` and
+    `get_err_type()` without requiring IPC.
+
+    '''
+
+    def test_unregistered_type_returns_none(self):
+        '''
+        An unregistered custom error name should yield
+        `None` from `get_err_type()`.
+
+        '''
+        result = get_err_type('CustomAppError')
+        assert result is None
+
+    def test_register_and_lookup(self):
+        '''
+        After `reg_err_types()`, the custom type should
+        be discoverable via `get_err_type()`.
+
+        '''
+        reg_err_types([CustomAppError])
+        result = get_err_type('CustomAppError')
+        assert result is CustomAppError
+
+    def test_register_multiple_types(self):
+        '''
+        Registering a list of types should make each
+        one individually resolvable.
+
+        '''
+        reg_err_types([
+            CustomAppError,
+            AnotherAppError,
+        ])
+        assert (
+            get_err_type('CustomAppError')
+            is CustomAppError
+        )
+        assert (
+            get_err_type('AnotherAppError')
+            is AnotherAppError
+        )
+
+    def test_builtin_types_always_resolve(self):
+        '''
+        Builtin error types like `RuntimeError` and
+        `ValueError` should always be found without
+        any prior registration.
+
+        '''
+        assert (
+            get_err_type('RuntimeError')
+            is RuntimeError
+        )
+        assert (
+            get_err_type('ValueError')
+            is ValueError
+        )
+
+    def test_tractor_native_types_resolve(self):
+        '''
+        `tractor`-internal exc types (e.g.
+        `ContextCancelled`) should always resolve.
+
+        '''
+        assert (
+            get_err_type('ContextCancelled')
+            is tractor.ContextCancelled
+        )
+
+    def test_boxed_type_str_without_ipc_msg(self):
+        '''
+        When a `RemoteActorError` is constructed
+        without an IPC msg (and no resolvable type),
+        `.boxed_type_str` should return `'<unknown>'`.
+
+        '''
+        rae = RemoteActorError('test')
+        assert rae.boxed_type_str == '<unknown>'
+
+
+# -- IPC-level integration tests --
+
+def test_registered_custom_err_relayed(
+    debug_mode: bool,
+    tpt_proto: str,
+):
+    '''
+    When a custom error type is registered via
+    `reg_err_types()` on BOTH sides of an IPC dialog,
+    the parent should receive a `RemoteActorError`
+    whose `.boxed_type` matches the original custom
+    error type.
+
+    '''
+    reg_err_types([CustomAppError])
+
+    async def main():
+        async with tractor.open_nursery(
+            debug_mode=debug_mode,
+            enable_transports=[tpt_proto],
+        ) as an:
+            ptl: Portal = await an.start_actor(
+                'custom-err-raiser',
+                enable_modules=[__name__],
+            )
+            async with ptl.open_context(
+                raise_custom_err,
+            ) as (ctx, sent):
+                assert not sent
+                try:
+                    await ctx.wait_for_result()
+                except RemoteActorError as rae:
+                    assert rae.boxed_type is CustomAppError
+                    assert rae.src_type is CustomAppError
+                    assert 'the app exploded remotely' in str(
+                        rae.tb_str
+                    )
+                    raise
+
+    with pytest.raises(RemoteActorError) as excinfo:
+        trio.run(main)
+
+    rae = excinfo.value
+    assert rae.boxed_type is CustomAppError
+
+
+def test_registered_another_err_relayed(
+    debug_mode: bool,
+    tpt_proto: str,
+):
+    '''
+    Same as above but for a different custom error
+    type to verify multi-type registration works
+    end-to-end over IPC.
+
+    '''
+    reg_err_types([AnotherAppError])
+
+    async def main():
+        async with tractor.open_nursery(
+            debug_mode=debug_mode,
+            enable_transports=[tpt_proto],
+        ) as an:
+            ptl: Portal = await an.start_actor(
+                'another-err-raiser',
+                enable_modules=[__name__],
+            )
+            async with ptl.open_context(
+                raise_another_err,
+            ) as (ctx, sent):
+                assert not sent
+                try:
+                    await ctx.wait_for_result()
+                except RemoteActorError as rae:
+                    assert (
+                        rae.boxed_type
+                        is AnotherAppError
+                    )
+                    raise
+
+            await an.cancel()
+
+    with pytest.raises(RemoteActorError) as excinfo:
+        trio.run(main)
+
+    rae = excinfo.value
+    assert rae.boxed_type is AnotherAppError
+
+
+def test_unregistered_err_still_relayed(
+    debug_mode: bool,
+    tpt_proto: str,
+):
+    '''
+    Verify that even when a custom error type is NOT registered via
+    `reg_err_types()`, the remote error is still relayed as
+    a `RemoteActorError` with all string-level info preserved
+    (traceback, type name, source actor uid).
+
+    The `.boxed_type` will be `None` (type obj can't be resolved) but
+    `.boxed_type_str` and `.src_type_str` still report the original
+    type name from the IPC msg.
+
+    This documents the expected limitation: without `reg_err_types()`
+    the `.boxed_type` property can NOT resolve to the original Python
+    type.
+
+    '''
+    # NOTE: intentionally do NOT call
+    # `reg_err_types([UnregisteredAppError])`
+
+    async def main():
+        async with tractor.open_nursery(
+            debug_mode=debug_mode,
+            enable_transports=[tpt_proto],
+        ) as an:
+            ptl: Portal = await an.start_actor(
+                'unreg-err-raiser',
+                enable_modules=[__name__],
+            )
+            async with ptl.open_context(
+                raise_unreg_err,
+            ) as (ctx, sent):
+                assert not sent
+                await ctx.wait_for_result()
+
+            await an.cancel()
+
+    with pytest.raises(RemoteActorError) as excinfo:
+        trio.run(main)
+
+    rae = excinfo.value
+
+    # the error IS relayed even without
+    # registration; type obj is unresolvable but
+    # all string-level info is preserved.
+    assert rae.boxed_type is None # NOT `UnregisteredAppError`
+    assert rae.src_type is None
+
+    # string names survive the IPC round-trip
+    # via the `Error` msg fields.
+    assert (
+        rae.src_type_str
+        ==
+        'UnregisteredAppError'
+    )
+    assert (
+        rae.boxed_type_str
+        ==
+        'UnregisteredAppError'
+    )
+
+    # original traceback content is preserved
+    assert 'this error type is unknown' in rae.tb_str
+    assert 'UnregisteredAppError' in rae.tb_str

tests/test_root_runtime.py

@@ -94,15 +94,15 @@ def test_runtime_vars_unset(
     after the root actor-runtime exits!
 
     '''
-    assert not tractor._state._runtime_vars['_debug_mode']
+    assert not tractor.runtime._state._runtime_vars['_debug_mode']
     async def main():
-        assert not tractor._state._runtime_vars['_debug_mode']
+        assert not tractor.runtime._state._runtime_vars['_debug_mode']
         async with tractor.open_nursery(
             debug_mode=True,
         ):
-            assert tractor._state._runtime_vars['_debug_mode']
+            assert tractor.runtime._state._runtime_vars['_debug_mode']
 
         # after runtime closure, should be reverted!
-        assert not tractor._state._runtime_vars['_debug_mode']
+        assert not tractor.runtime._state._runtime_vars['_debug_mode']
 
     trio.run(main)

tests/test_rpc.py

@@ -110,7 +110,7 @@ def test_rpc_errors(
         ) as n:
 
             actor = tractor.current_actor()
-            assert actor.is_arbiter
+            assert actor.is_registrar
             await n.run_in_actor(
                 sleep_back_actor,
                 actor_name=subactor_requests_to,

tests/test_spawning.py

@@ -39,7 +39,7 @@ async def spawn(
         ):
             # now runtime exists
             actor: tractor.Actor = tractor.current_actor()
-            assert actor.is_arbiter == should_be_root
+            assert actor.is_registrar == should_be_root
 
             # spawns subproc here
             portal: tractor.Portal = await an.run_in_actor(
@@ -68,7 +68,7 @@ async def spawn(
             assert result == 10
             return result
     else:
-        assert actor.is_arbiter == should_be_root
+        assert actor.is_registrar == should_be_root
         return 10
 
 
@@ -181,7 +181,7 @@ def test_loglevel_propagated_to_subactor(
 
     async def main():
         async with tractor.open_nursery(
-            name='arbiter',
+            name='registrar',
             start_method=start_method,
             arbiter_addr=reg_addr,
 

tractor/__init__.py

@@ -30,21 +30,23 @@ from ._streaming import (
     MsgStream as MsgStream,
     stream as stream,
 )
-from ._discovery import (
+from .discovery._discovery import (
     get_registry as get_registry,
     find_actor as find_actor,
     wait_for_actor as wait_for_actor,
     query_actor as query_actor,
 )
-from ._supervise import (
+from .runtime._supervise import (
     open_nursery as open_nursery,
     ActorNursery as ActorNursery,
 )
-from ._state import (
+from .runtime._state import (
+    RuntimeVars as RuntimeVars,
     current_actor as current_actor,
-    is_root_process as is_root_process,
     current_ipc_ctx as current_ipc_ctx,
-    debug_mode as debug_mode
+    debug_mode as debug_mode,
+    get_runtime_vars as get_runtime_vars,
+    is_root_process as is_root_process,
 )
 from ._exceptions import (
     ContextCancelled as ContextCancelled,
@@ -65,6 +67,10 @@ from ._root import (
     open_root_actor as open_root_actor,
 )
 from .ipc import Channel as Channel
-from ._portal import Portal as Portal
-from ._runtime import Actor as Actor
+from .runtime._portal import Portal as Portal
+from .runtime._runtime import Actor as Actor
+from .discovery._registry import (
+    Registrar as Registrar,
+    Arbiter as Arbiter,
+)
 # from . import hilevel as hilevel

tractor/_child.py

@@ -22,8 +22,8 @@ import argparse
 
 from ast import literal_eval
 
-from ._runtime import Actor
-from ._entry import _trio_main
+from .runtime._runtime import Actor
+from .spawn._entry import _trio_main
 
 
 def parse_uid(arg):

tractor/_context.py

@@ -97,7 +97,7 @@ from ._streaming import (
     MsgStream,
     open_stream_from_ctx,
 )
-from ._state import (
+from .runtime._state import (
     current_actor,
     debug_mode,
     _ctxvar_Context,
@@ -107,8 +107,8 @@ from .trionics import (
 )
 # ------ - ------
 if TYPE_CHECKING:
-    from ._portal import Portal
-    from ._runtime import Actor
+    from .runtime._portal import Portal
+    from .runtime._runtime import Actor
     from .ipc._transport import MsgTransport
     from .devx._frame_stack import (
         CallerInfo,

tractor/_exceptions.py

@@ -43,7 +43,7 @@ from msgspec import (
     ValidationError,
 )
 
-from tractor._state import current_actor
+from tractor.runtime._state import current_actor
 from tractor.log import get_logger
 from tractor.msg import (
     Error,
@@ -187,7 +187,31 @@ _body_fields: list[str] = list(
 )
 
 
-def get_err_type(type_name: str) -> BaseException|None:
+def reg_err_types(
+    exc_types: list[Type[Exception]],
+) -> None:
+    '''
+    Register custom exception types for local lookup.
+
+    Such that error types can be registered by an external
+    `tractor`-use-app code base which are expected to be raised
+    remotely; enables them being re-raised on the receiver side of
+    some inter-actor IPC dialog.
+
+    '''
+    for exc_type in exc_types:
+        log.debug(
+            f'Register custom exception,\n'
+            f'{exc_type!r}\n'
+        )
+        setattr(
+            _this_mod,
+            exc_type.__name__,
+            exc_type,
+        )
+
+
+def get_err_type(type_name: str) -> Type[BaseException]|None:
     '''
     Look up an exception type by name from the set of locally known
     namespaces:
@@ -301,7 +325,8 @@ class RemoteActorError(Exception):
         # also pertains to our long long oustanding issue XD
         # https://github.com/goodboy/tractor/issues/5
         self._boxed_type: BaseException = boxed_type
-        self._src_type: BaseException|None = None
+        self._src_type: Type[BaseException]|None = None
+        self._src_type_resolved: bool = False
         self._ipc_msg: Error|None = ipc_msg
         self._extra_msgdata = extra_msgdata
 
@@ -410,24 +435,41 @@ class RemoteActorError(Exception):
         return self._ipc_msg.src_type_str
 
     @property
-    def src_type(self) -> str:
+    def src_type(self) -> Type[BaseException]|None:
         '''
-        Error type raised by original remote faulting actor.
+        Error type raised by original remote faulting
+        actor.
 
-        When the error has only been relayed a single actor-hop
-        this will be the same as the `.boxed_type`.
+        When the error has only been relayed a single
+        actor-hop this will be the same as
+        `.boxed_type`.
+
+        If the type can not be resolved locally (i.e.
+        it was not registered via `reg_err_types()`)
+        a warning is logged and `None` is returned;
+        all string-level error info (`.src_type_str`,
+        `.tb_str`, etc.) remains available.
 
         '''
-        if self._src_type is None:
+        if not self._src_type_resolved:
+            self._src_type_resolved = True
+
+            if self._ipc_msg is None:
+                return None
+
             self._src_type = get_err_type(
                 self._ipc_msg.src_type_str
             )
-
             if not self._src_type:
-                raise TypeError(
-                    f'Failed to lookup src error type with '
-                    f'`tractor._exceptions.get_err_type()` :\n'
-                    f'{self.src_type_str}'
+                log.warning(
+                    f'Failed to lookup src error type via\n'
+                    f'`tractor._exceptions.get_err_type()`:\n'
+                    f'\n'
+                    f'`{self._ipc_msg.src_type_str}`'
+                    f' is not registered!\n'
+                    f'\n'
+                    f'Call `reg_err_types()` to enable'
+                    f' full type reconstruction.\n'
                 )
 
         return self._src_type
@@ -435,20 +477,30 @@ class RemoteActorError(Exception):
     @property
     def boxed_type_str(self) -> str:
         '''
-        String-name of the (last hop's) boxed error type.
+        String-name of the (last hop's) boxed error
+        type.
+
+        Falls back to the IPC-msg-encoded type-name
+        str when the type can not be resolved locally
+        (e.g. unregistered custom errors).
 
         '''
         # TODO, maybe support also serializing the
-        # `ExceptionGroup.exeptions: list[BaseException]` set under
-        # certain conditions?
+        # `ExceptionGroup.exceptions: list[BaseException]`
+        # set under certain conditions?
         bt: Type[BaseException] = self.boxed_type
         if bt:
             return str(bt.__name__)
 
-        return ''
+        # fallback to the str name from the IPC msg
+        # when the type obj can't be resolved.
+        if self._ipc_msg:
+            return self._ipc_msg.boxed_type_str
+
+        return '<unknown>'
 
     @property
-    def boxed_type(self) -> Type[BaseException]:
+    def boxed_type(self) -> Type[BaseException]|None:
         '''
         Error type boxed by last actor IPC hop.
 
@@ -677,10 +729,22 @@ class RemoteActorError(Exception):
         failing actor's remote env.
 
         '''
-        # TODO: better tb insertion and all the fancier dunder
-        # metadata stuff as per `.__context__` etc. and friends:
+        # TODO: better tb insertion and all the fancier
+        # dunder metadata stuff as per `.__context__`
+        # etc. and friends:
         # https://github.com/python-trio/trio/issues/611
-        src_type_ref: Type[BaseException] = self.src_type
+        src_type_ref: Type[BaseException]|None = (
+            self.src_type
+        )
+        if src_type_ref is None:
+            # unresolvable type: fall back to
+            # a `RuntimeError` preserving original
+            # traceback + type name.
+            return RuntimeError(
+                f'{self.src_type_str}: '
+                f'{self.tb_str}'
+            )
+
         return src_type_ref(self.tb_str)
 
     # TODO: local recontruction of nested inception for a given
@@ -1209,14 +1273,31 @@ def unpack_error(
     if not isinstance(msg, Error):
         return None
 
-    # try to lookup a suitable error type from the local runtime
-    # env then use it to construct a local instance.
-    # boxed_type_str: str = error_dict['boxed_type_str']
+    # try to lookup a suitable error type from the
+    # local runtime env then use it to construct a
+    # local instance.
     boxed_type_str: str = msg.boxed_type_str
-    boxed_type: Type[BaseException] = get_err_type(boxed_type_str)
+    boxed_type: Type[BaseException]|None = get_err_type(
+        boxed_type_str
+    )
 
-    # retrieve the error's msg-encoded remotoe-env info
-    message: str = f'remote task raised a {msg.boxed_type_str!r}\n'
+    if boxed_type is None:
+        log.warning(
+            f'Failed to resolve remote error type\n'
+            f'`{boxed_type_str}` - boxing as\n'
+            f'`RemoteActorError` with original\n'
+            f'traceback preserved.\n'
+            f'\n'
+            f'Call `reg_err_types()` to enable\n'
+            f'full type reconstruction.\n'
+        )
+
+    # retrieve the error's msg-encoded remote-env
+    # info
+    message: str = (
+        f'remote task raised a '
+        f'{msg.boxed_type_str!r}\n'
+    )
 
     # TODO: do we even really need these checks for RAEs?
     if boxed_type_str in [

tractor/_root.py

@@ -37,19 +37,20 @@ import warnings
 
 import trio
 
-from . import _runtime
+from .runtime import _runtime
+from .discovery._registry import Registrar
 from .devx import (
     debug,
     _frame_stack,
     pformat as _pformat,
 )
-from . import _spawn
-from . import _state
+from .spawn import _spawn
+from .runtime import _state
 from . import log
 from .ipc import (
     _connect_chan,
 )
-from ._addr import (
+from .discovery._addr import (
     Address,
     UnwrappedAddress,
     default_lo_addrs,
@@ -267,7 +268,6 @@ async def open_root_actor(
         if start_method is not None:
             _spawn.try_set_start_method(start_method)
 
-        # TODO! remove this ASAP!
         if arbiter_addr is not None:
             warnings.warn(
                 '`arbiter_addr` is now deprecated\n'
@@ -400,7 +400,7 @@ async def open_root_actor(
                     'registry socket(s) already bound'
                 )
 
-            # we were able to connect to an arbiter
+            # we were able to connect to a registrar
             logger.info(
                 f'Registry(s) seem(s) to exist @ {ponged_addrs}'
             )
@@ -453,8 +453,7 @@ async def open_root_actor(
             # https://github.com/goodboy/tractor/pull/348
             # https://github.com/goodboy/tractor/issues/296
 
-            # TODO: rename as `RootActor` or is that even necessary?
-            actor = _runtime.Arbiter(
+            actor = Registrar(
                 name=name or 'registrar',
                 uuid=mk_uuid(),
                 registry_addrs=registry_addrs,

tractor/_streaming.py

@@ -55,7 +55,7 @@ from tractor.msg import (
 )
 
 if TYPE_CHECKING:
-    from ._runtime import Actor
+    from .runtime._runtime import Actor
     from ._context import Context
     from .ipc import Channel
 

tractor/_testing/addr.py

@@ -26,9 +26,7 @@ import random
 from typing import (
     Type,
 )
-from tractor import (
-    _addr,
-)
+from tractor.discovery import _addr
 
 
 def get_rando_addr(

tractor/_testing/pytest.py

@@ -21,17 +21,27 @@ and applications.
 '''
 from functools import (
     partial,
-    wraps,
 )
 import inspect
 import platform
+from typing import (
+    Callable,
+    Type,
+)
 
 import pytest
 import tractor
 import trio
+import wrapt
 
 
-def tractor_test(fn):
+def tractor_test(
+    wrapped: Callable|None = None,
+    *,
+    # @tractor_test(<deco-params>)
+    timeout:float = 30,
+    hide_tb: bool = True,
+):
     '''
     Decorator for async test fns to decorator-wrap them as "native"
     looking sync funcs runnable by `pytest` and auto invoked with
@@ -45,8 +55,18 @@ def tractor_test(fn):
     Basic deco use:
     ---------------
 
-      @tractor_test
-      async def test_whatever():
+      @tractor_test(
+        timeout=10,
+      )
+      async def test_whatever(
+          # fixture param declarations
+          loglevel: str,
+          start_method: str,
+          reg_addr: tuple,
+          tpt_proto: str,
+          debug_mode: bool,
+      ):
+          # already inside a root-actor runtime `trio.Task`
           await ...
 
 
@@ -55,7 +75,7 @@ def tractor_test(fn):
     If any of the following fixture are requested by the wrapped test
     fn (via normal func-args declaration),
 
-    - `reg_addr` (a socket addr tuple where arbiter is listening)
+    - `reg_addr` (a socket addr tuple where registrar is listening)
     - `loglevel` (logging level passed to tractor internals)
     - `start_method` (subprocess spawning backend)
 
@@ -67,52 +87,69 @@ def tractor_test(fn):
     `tractor.open_root_actor()` funcargs.
 
     '''
-    @wraps(fn)
+    __tracebackhide__: bool = hide_tb
+
+    # handle the decorator not called with () case.
+    # i.e. in `wrapt` support a deco-with-optional-args,
+    # https://wrapt.readthedocs.io/en/master/decorators.html#decorators-with-optional-arguments
+    if wrapped is None:
+        return wrapt.PartialCallableObjectProxy(
+            tractor_test,
+            timeout=timeout,
+            hide_tb=hide_tb
+        )
+
+    @wrapt.decorator
     def wrapper(
-        *args,
-        loglevel=None,
-        reg_addr=None,
-        start_method: str|None = None,
-        debug_mode: bool = False,
-        tpt_proto: str|None=None,
-        **kwargs
+        wrapped: Callable,
+        instance: object|Type|None,
+        args: tuple,
+        kwargs: dict,
     ):
-        # __tracebackhide__ = True
+        __tracebackhide__: bool = hide_tb
 
-        # NOTE: inject ant test func declared fixture
-        # names by manually checking!
-        if 'reg_addr' in inspect.signature(fn).parameters:
-            # injects test suite fixture value to test as well
-            # as `run()`
-            kwargs['reg_addr'] = reg_addr
+        # NOTE, ensure we inject any test-fn declared fixture names.
+        for kw in [
+            'reg_addr',
+            'loglevel',
+            'start_method',
+            'debug_mode',
+            'tpt_proto',
+            'timeout',
+        ]:
+            if kw in inspect.signature(wrapped).parameters:
+                assert kw in kwargs
 
-        if 'loglevel' in inspect.signature(fn).parameters:
-            # allows test suites to define a 'loglevel' fixture
-            # that activates the internal logging
-            kwargs['loglevel'] = loglevel
+        start_method = kwargs.get('start_method')
+        if platform.system() == "Windows":
+            if start_method is None:
+                kwargs['start_method'] = 'trio'
+            elif start_method != 'trio':
+                raise ValueError(
+                    'ONLY the `start_method="trio"` is supported on Windows.'
+                )
 
-        if start_method is None:
-            if platform.system() == "Windows":
-                start_method = 'trio'
+        # open a root-actor, passing certain
+        # `tractor`-runtime-settings, then invoke the test-fn body as
+        # the root-most task.
+        #
+        # https://wrapt.readthedocs.io/en/master/decorators.html#processing-function-arguments
+        async def _main(
+            *args,
 
-        if 'start_method' in inspect.signature(fn).parameters:
-            # set of subprocess spawning backends
-            kwargs['start_method'] = start_method
+            # runtime-settings
+            loglevel:str|None = None,
+            reg_addr:tuple|None = None,
+            start_method: str|None = None,
+            debug_mode: bool = False,
+            tpt_proto: str|None = None,
 
-        if 'debug_mode' in inspect.signature(fn).parameters:
-            # set of subprocess spawning backends
-            kwargs['debug_mode'] = debug_mode
+            **kwargs,
+        ):
+            __tracebackhide__: bool = hide_tb
 
-        if 'tpt_proto' in inspect.signature(fn).parameters:
-            # set of subprocess spawning backends
-            kwargs['tpt_proto'] = tpt_proto
-
-        if kwargs:
-
-            # use explicit root actor start
-            async def _main():
+            with trio.fail_after(timeout):
                 async with tractor.open_root_actor(
-                    # **kwargs,
                     registry_addrs=[reg_addr] if reg_addr else None,
                     loglevel=loglevel,
                     start_method=start_method,
@@ -121,17 +158,31 @@ def tractor_test(fn):
                     debug_mode=debug_mode,
 
                 ):
-                    await fn(*args, **kwargs)
+                    # invoke test-fn body IN THIS task
+                    await wrapped(
+                        *args,
+                        **kwargs,
+                    )
 
-            main = _main
+        funcname = wrapped.__name__
+        if not inspect.iscoroutinefunction(wrapped):
+            raise TypeError(
+                f"Test-fn {funcname!r} must be an async-function !!"
+            )
 
-        else:
-            # use implicit root actor start
-            main = partial(fn, *args, **kwargs)
+        # invoke runtime via a root task.
+        return trio.run(
+            partial(
+                _main,
+                *args,
+                **kwargs,
+            )
+        )
 
-        return trio.run(main)
 
-    return wrapper
+    return wrapper(
+        wrapped,
+    )
 
 
 def pytest_addoption(
@@ -179,7 +230,8 @@ def pytest_addoption(
 
 def pytest_configure(config):
     backend = config.option.spawn_backend
-    tractor._spawn.try_set_start_method(backend)
+    from tractor.spawn._spawn import try_set_start_method
+    try_set_start_method(backend)
 
     # register custom marks to avoid warnings see,
     # https://docs.pytest.org/en/stable/how-to/writing_plugins.html#registering-custom-markers
@@ -225,7 +277,8 @@ def tpt_protos(request) -> list[str]:
 
     # XXX ensure we support the protocol by name via lookup!
     for proto_key in proto_keys:
-        addr_type = tractor._addr._address_types[proto_key]
+        from tractor.discovery import _addr
+        addr_type = _addr._address_types[proto_key]
         assert addr_type.proto_key == proto_key
 
     yield proto_keys
@@ -256,7 +309,7 @@ def tpt_proto(
     #             f'tpt-proto={proto_key!r}\n'
     #         )
 
-    from tractor import _state
+    from tractor.runtime import _state
     if _state._def_tpt_proto != proto_key:
         _state._def_tpt_proto = proto_key
         _state._runtime_vars['_enable_tpts'] = [

tractor/devx/_stackscope.py

@@ -45,17 +45,15 @@ from typing import (
 )
 
 import trio
-from tractor import (
-    _state,
-    log as logmod,
-)
+from tractor.runtime import _state
+from tractor import log as logmod
 from tractor.devx import debug
 
 log = logmod.get_logger()
 
 
 if TYPE_CHECKING:
-    from tractor._spawn import ProcessType
+    from tractor.spawn._spawn import ProcessType
     from tractor import (
         Actor,
         ActorNursery,

tractor/devx/debug/_post_mortem.py

@@ -53,8 +53,8 @@ import trio
 from tractor._exceptions import (
     NoRuntime,
 )
-from tractor import _state
-from tractor._state import (
+from tractor.runtime import _state
+from tractor.runtime._state import (
     current_actor,
     debug_mode,
 )
@@ -76,7 +76,7 @@ from ._repl import (
 
 if TYPE_CHECKING:
     from trio.lowlevel import Task
-    from tractor._runtime import (
+    from tractor.runtime._runtime import (
         Actor,
     )
 

tractor/devx/debug/_repl.py

@@ -25,7 +25,7 @@ from functools import (
 import os
 
 import pdbp
-from tractor._state import (
+from tractor.runtime._state import (
     is_root_process,
 )
 

tractor/devx/debug/_sigint.py

@@ -27,7 +27,7 @@ from typing import (
 )
 import trio
 from tractor.log import get_logger
-from tractor._state import (
+from tractor.runtime._state import (
     current_actor,
     is_root_process,
 )
@@ -44,7 +44,7 @@ if TYPE_CHECKING:
     from tractor.ipc import (
         Channel,
     )
-    from tractor._runtime import (
+    from tractor.runtime._runtime import (
         Actor,
     )
 

tractor/devx/debug/_sync.py

@@ -40,7 +40,7 @@ from trio.lowlevel import (
     Task,
 )
 from tractor._context import Context
-from tractor._state import (
+from tractor.runtime._state import (
     current_actor,
     debug_mode,
     is_root_process,

tractor/devx/debug/_trace.py

@@ -55,12 +55,12 @@ import tractor
 from tractor.log import get_logger
 from tractor.to_asyncio import run_trio_task_in_future
 from tractor._context import Context
-from tractor import _state
+from tractor.runtime import _state
 from tractor._exceptions import (
     NoRuntime,
     InternalError,
 )
-from tractor._state import (
+from tractor.runtime._state import (
     current_actor,
     current_ipc_ctx,
     is_root_process,
@@ -87,7 +87,7 @@ from ..pformat import (
 if TYPE_CHECKING:
     from trio.lowlevel import Task
     from threading import Thread
-    from tractor._runtime import (
+    from tractor.runtime._runtime import (
         Actor,
     )
     # from ._post_mortem import BoxedMaybeException

tractor/devx/debug/_tty_lock.py

@@ -55,12 +55,12 @@ import tractor
 from tractor.to_asyncio import run_trio_task_in_future
 from tractor.log import get_logger
 from tractor._context import Context
-from tractor import _state
+from tractor.runtime import _state
 from tractor._exceptions import (
     DebugRequestError,
     InternalError,
 )
-from tractor._state import (
+from tractor.runtime._state import (
     current_actor,
     is_root_process,
 )
@@ -71,7 +71,7 @@ if TYPE_CHECKING:
     from tractor.ipc import (
         IPCServer,
     )
-    from tractor._runtime import (
+    from tractor.runtime._runtime import (
         Actor,
     )
     from ._repl import (
@@ -1013,7 +1013,7 @@ async def request_root_stdio_lock(
     DebugStatus.req_task = current_task()
     req_err: BaseException|None = None
     try:
-        from tractor._discovery import get_root
+        from tractor.discovery._discovery import get_root
         # NOTE: we need this to ensure that this task exits
         # BEFORE the REPl instance raises an error like
         # `bdb.BdbQuit` directly, OW you get a trio cs stack

tractor/discovery/__init__.py

@@ -0,0 +1,26 @@
+# tractor: structured concurrent "actors".
+# Copyright 2018-eternity Tyler Goodlet.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+'''
+Discovery (protocols) API for automatic addressing
+and location management of (service) actors.
+
+NOTE: to avoid circular imports, this ``__init__``
+does NOT eagerly import submodules. Use direct
+module paths like ``tractor.discovery._addr`` or
+``tractor.discovery._discovery`` instead.
+
+'''

tractor/discovery/_addr.py

@@ -27,15 +27,15 @@ from trio import (
     SocketListener,
 )
 
-from .log import get_logger
-from ._state import (
+from ..log import get_logger
+from ..runtime._state import (
     _def_tpt_proto,
 )
-from .ipc._tcp import TCPAddress
-from .ipc._uds import UDSAddress
+from ..ipc._tcp import TCPAddress
+from ..ipc._uds import UDSAddress
 
 if TYPE_CHECKING:
-    from ._runtime import Actor
+    from ..runtime._runtime import Actor
 
 log = get_logger()
 

tractor/discovery/_discovery.py

@@ -28,29 +28,29 @@ from typing import (
 from contextlib import asynccontextmanager as acm
 
 from tractor.log import get_logger
-from .trionics import (
+from ..trionics import (
     gather_contexts,
     collapse_eg,
 )
-from .ipc import _connect_chan, Channel
+from ..ipc import _connect_chan, Channel
 from ._addr import (
     UnwrappedAddress,
     Address,
     wrap_address
 )
-from ._portal import (
+from ..runtime._portal import (
     Portal,
     open_portal,
     LocalPortal,
 )
-from ._state import (
+from ..runtime._state import (
     current_actor,
     _runtime_vars,
     _def_tpt_proto,
 )
 
 if TYPE_CHECKING:
-    from ._runtime import Actor
+    from ..runtime._runtime import Actor
 
 
 log = get_logger()
@@ -60,7 +60,7 @@ log = get_logger()
 async def get_registry(
     addr: UnwrappedAddress|None = None,
 ) -> AsyncGenerator[
-    Portal | LocalPortal | None,
+    Portal|LocalPortal|None,
     None,
 ]:
     '''
@@ -72,8 +72,8 @@ async def get_registry(
     '''
     actor: Actor = current_actor()
     if actor.is_registrar:
-        # we're already the arbiter
-        # (likely a re-entrant call from the arbiter actor)
+        # we're already the registrar
+        # (likely a re-entrant call from the registrar actor)
         yield LocalPortal(
             actor,
             Channel(transport=None)
@@ -153,21 +153,27 @@ async def query_actor(
     regaddr: UnwrappedAddress|None = None,
 
 ) -> AsyncGenerator[
-    UnwrappedAddress|None,
+    tuple[UnwrappedAddress|None, Portal|LocalPortal|None],
     None,
 ]:
     '''
     Lookup a transport address (by actor name) via querying a registrar
     listening @ `regaddr`.
 
-    Returns the transport protocol (socket) address or `None` if no
-    entry under that name exists.
+    Yields a `tuple` of `(addr, reg_portal)` where,
+    - `addr` is the transport protocol (socket) address or `None` if
+      no entry under that name exists,
+    - `reg_portal` is the `Portal` (or `LocalPortal` when the
+      current actor is the registrar) used for the lookup (or
+      `None` when the peer was found locally via
+      `get_peer_by_name()`).
 
     '''
     actor: Actor = current_actor()
     if (
         name == 'registrar'
-        and actor.is_registrar
+        and
+        actor.is_registrar
     ):
         raise RuntimeError(
             'The current actor IS the registry!?'
@@ -175,10 +181,10 @@ async def query_actor(
 
     maybe_peers: list[Channel]|None = get_peer_by_name(name)
     if maybe_peers:
-        yield maybe_peers[0].raddr
+        yield maybe_peers[0].raddr, None
         return
 
-    reg_portal: Portal
+    reg_portal: Portal|LocalPortal
     regaddr: Address = wrap_address(regaddr) or actor.reg_addrs[0]
     async with get_registry(regaddr) as reg_portal:
         # TODO: return portals to all available actors - for now
@@ -188,8 +194,7 @@ async def query_actor(
             'find_actor',
             name=name,
         )
-        yield addr
-
+        yield addr, reg_portal
 
 @acm
 async def maybe_open_portal(
@@ -204,15 +209,49 @@ async def maybe_open_portal(
     async with query_actor(
         name=name,
         regaddr=addr,
-    ) as addr:
-        pass
+    ) as (addr, reg_portal):
+        if not addr:
+            yield None
+            return
 
-    if addr:
-        async with _connect_chan(addr) as chan:
-            async with open_portal(chan) as portal:
-                yield portal
-    else:
-        yield None
+        try:
+            async with _connect_chan(addr) as chan:
+                async with open_portal(chan) as portal:
+                    yield portal
+
+        # most likely we were unable to connect the
+        # transport and there is likely a stale entry in
+        # the registry actor's table, thus we need to
+        # instruct it to clear that stale entry and then
+        # more silently (pretend there was no reason but
+        # to) indicate that the target actor can't be
+        # contacted at that addr.
+        except OSError:
+            # NOTE: ensure we delete the stale entry
+            # from the registrar actor when available.
+            if reg_portal is not None:
+                uid: tuple[str, str]|None = await reg_portal.run_from_ns(
+                    'self',
+                    'delete_addr',
+                    addr=addr,
+                )
+                if uid:
+                    log.warning(
+                        f'Deleted stale registry entry !\n'
+                        f'addr: {addr!r}\n'
+                        f'uid: {uid!r}\n'
+                    )
+                else:
+                    log.warning(
+                        f'No registry entry found for addr: {addr!r}'
+                    )
+            else:
+                log.warning(
+                    f'Connection to {addr!r} failed'
+                    f' and no registry portal available'
+                    f' to delete stale entry.'
+                )
+            yield None
 
 
 @acm
@@ -229,10 +268,10 @@ async def find_actor(
     None,
 ]:
     '''
-    Ask the arbiter to find actor(s) by name.
+    Ask the registrar to find actor(s) by name.
 
-    Returns a connected portal to the last registered matching actor
-    known to the arbiter.
+    Returns a connected portal to the last registered
+    matching actor known to the registrar.
 
     '''
     # optimization path, use any pre-existing peer channel
@@ -280,7 +319,7 @@ async def find_actor(
         if not any(portals):
             if raise_on_none:
                 raise RuntimeError(
-                    f'No actor "{name}" found registered @ {registry_addrs}'
+                    f'No actor {name!r} found registered @ {registry_addrs!r}'
                 )
             yield None
             return

tractor/discovery/_registry.py

@@ -0,0 +1,253 @@
+# tractor: structured concurrent "actors".
+# Copyright 2018-eternity Tyler Goodlet.
+
+# This program is free software: you can redistribute it and/or
+# modify it under the terms of the GNU Affero General Public
+# License as published by the Free Software Foundation, either
+# version 3 of the License, or (at your option) any later
+# version.
+
+# This program is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+# PURPOSE. See the GNU Affero General Public License for more
+# details.
+
+# You should have received a copy of the GNU Affero General
+# Public License along with this program. If not, see
+# <https://www.gnu.org/licenses/>.
+
+'''
+Actor-registry for process-tree service discovery.
+
+The `Registrar` is a special `Actor` subtype that serves as
+the process-tree's name-registry, tracking actor
+name-to-address mappings so peers can discover each other.
+
+'''
+from __future__ import annotations
+
+from bidict import bidict
+import trio
+
+from ..runtime._runtime import Actor
+from ._addr import (
+    UnwrappedAddress,
+    Address,
+    wrap_address,
+)
+from ..devx import debug
+from ..log import get_logger
+
+
+log = get_logger('tractor')
+
+
+class Registrar(Actor):
+    '''
+    A special registrar `Actor` who can contact all other
+    actors within its immediate process tree and keeps
+    a registry of others meant to be discoverable in
+    a distributed application.
+
+    Normally the registrar is also the "root actor" and
+    thus always has access to the top-most-level actor
+    (process) nursery.
+
+    By default, the registrar is always initialized when
+    and if no other registrar socket addrs have been
+    specified to runtime init entry-points (such as
+    `open_root_actor()` or `open_nursery()`). Any time
+    a new main process is launched (and thus a new root
+    actor created) and, no existing registrar can be
+    contacted at the provided `registry_addr`, then
+    a new one is always created; however, if one can be
+    reached it is used.
+
+    Normally a distributed app requires at least one
+    registrar per logical host where for that given
+    "host space" (aka localhost IPC domain of addresses)
+    it is responsible for making all other host (local
+    address) bound actors *discoverable* to external
+    actor trees running on remote hosts.
+
+    '''
+    is_registrar = True
+
+    def is_registry(self) -> bool:
+        return self.is_registrar
+
+    def __init__(
+        self,
+        *args,
+        **kwargs,
+    ) -> None:
+
+        self._registry: bidict[
+            tuple[str, str],
+            UnwrappedAddress,
+        ] = bidict({})
+        self._waiters: dict[
+            str,
+            # either an event to sync to receiving an
+            # actor uid (which is filled in once the actor
+            # has sucessfully registered), or that uid
+            # after registry is complete.
+            list[trio.Event|tuple[str, str]]
+        ] = {}
+
+        super().__init__(*args, **kwargs)
+
+    async def find_actor(
+        self,
+        name: str,
+
+    ) -> UnwrappedAddress|None:
+
+        for uid, addr in self._registry.items():
+            if name in uid:
+                return addr
+
+        return None
+
+    async def get_registry(
+        self
+
+    ) -> dict[str, UnwrappedAddress]:
+        '''
+        Return current name registry.
+
+        This method is async to allow for cross-actor
+        invocation.
+
+        '''
+        # NOTE: requires ``strict_map_key=False`` to the
+        # msgpack unpacker since we have tuples as keys
+        # (note this makes the registrar suscetible to
+        # hashdos):
+        # https://github.com/msgpack/msgpack-python#major-breaking-changes-in-msgpack-10
+        return {
+            '.'.join(key): val
+            for key, val in self._registry.items()
+        }
+
+    async def wait_for_actor(
+        self,
+        name: str,
+
+    ) -> list[UnwrappedAddress]:
+        '''
+        Wait for a particular actor to register.
+
+        This is a blocking call if no actor by the
+        provided name is currently registered.
+
+        '''
+        addrs: list[UnwrappedAddress] = []
+        addr: UnwrappedAddress
+
+        mailbox_info: str = (
+            'Actor registry contact infos:\n'
+        )
+        for uid, addr in self._registry.items():
+            mailbox_info += (
+                f'|_uid: {uid}\n'
+                f'|_addr: {addr}\n\n'
+            )
+            if name == uid[0]:
+                addrs.append(addr)
+
+        if not addrs:
+            waiter = trio.Event()
+            self._waiters.setdefault(
+                name, []
+            ).append(waiter)
+            await waiter.wait()
+
+            for uid in self._waiters[name]:
+                if not isinstance(uid, trio.Event):
+                    addrs.append(
+                        self._registry[uid]
+                    )
+
+        log.runtime(mailbox_info)
+        return addrs
+
+    async def register_actor(
+        self,
+        uid: tuple[str, str],
+        addr: UnwrappedAddress
+    ) -> None:
+        uid = name, hash = (
+            str(uid[0]),
+            str(uid[1]),
+        )
+        waddr: Address = wrap_address(addr)
+        if not waddr.is_valid:
+            # should never be 0-dynamic-os-alloc
+            await debug.pause()
+
+        # XXX NOTE, value must also be hashable AND since
+        # `._registry` is a `bidict` values must be unique;
+        # use `.forceput()` to replace any prior (stale)
+        # entries that might map a different uid to the same
+        # addr (e.g. after an unclean shutdown or
+        # actor-restart reusing the same address).
+        self._registry.forceput(uid, tuple(addr))
+
+        # pop and signal all waiter events
+        events = self._waiters.pop(name, [])
+        self._waiters.setdefault(
+            name, []
+        ).append(uid)
+        for event in events:
+            if isinstance(event, trio.Event):
+                event.set()
+
+    async def unregister_actor(
+        self,
+        uid: tuple[str, str]
+
+    ) -> None:
+        uid = (str(uid[0]), str(uid[1]))
+        entry: tuple = self._registry.pop(
+            uid, None
+        )
+        if entry is None:
+            log.warning(
+                f'Request to de-register'
+                f' {uid!r} failed?'
+            )
+
+    async def delete_addr(
+        self,
+        addr: tuple[str, int|str]|list[str|int],
+    ) -> tuple[str, str]|None:
+        # NOTE: `addr` arrives as a `list` over IPC
+        # (msgpack deserializes tuples -> lists) so
+        # coerce to `tuple` for the bidict hash lookup.
+        uid: tuple[str, str]|None = (
+            self._registry.inverse.pop(
+                tuple(addr),
+                None,
+            )
+        )
+        if uid:
+            report: str = (
+                'Deleting registry-entry for,\n'
+            )
+        else:
+            report: str = (
+                'No registry entry for,\n'
+            )
+
+        log.warning(
+            report
+            +
+            f'{addr!r}@{uid!r}'
+        )
+        return uid
+
+
+# Backward compat alias
+Arbiter = Registrar

tractor/experimental/_pubsub.py

@@ -146,7 +146,7 @@ _pubtask2lock: dict[str, trio.StrictFIFOLock] = {}
 
 
 def pub(
-    wrapped: typing.Callable | None = None,
+    wrapped: typing.Callable|None = None,
     *,
     tasks: set[str] = set(),
 ):
@@ -244,8 +244,12 @@ def pub(
         task2lock[name] = trio.StrictFIFOLock()
 
     @wrapt.decorator
-    async def wrapper(agen, instance, args, kwargs):
-
+    async def wrapper(
+        agen,
+        instance,
+        args,
+        kwargs,
+    ):
         # XXX: this is used to extract arguments properly as per the
         # `wrapt` docs
         async def _execute(

tractor/ipc/_chan.py

@@ -39,7 +39,7 @@ from ._types import (
     transport_from_addr,
     transport_from_stream,
 )
-from tractor._addr import (
+from tractor.discovery._addr import (
     is_wrapped_addr,
     wrap_address,
     Address,

tractor/ipc/_server.py

@@ -50,26 +50,24 @@ from ..devx.pformat import (
 from .._exceptions import (
     TransportClosed,
 )
-from .. import _rpc
+from ..runtime import _rpc
 from ..msg import (
     MsgType,
     Struct,
     types as msgtypes,
 )
 from ..trionics import maybe_open_nursery
-from .. import (
-    _state,
-    log,
-)
-from .._addr import Address
+from ..runtime import _state
+from .. import log
+from ..discovery._addr import Address
 from ._chan import Channel
 from ._transport import MsgTransport
 from ._uds import UDSAddress
 from ._tcp import TCPAddress
 
 if TYPE_CHECKING:
-    from .._runtime import Actor
-    from .._supervise import ActorNursery
+    from ..runtime._runtime import Actor
+    from ..runtime._supervise import ActorNursery
 
 
 log = log.get_logger()
@@ -357,7 +355,7 @@ async def handle_stream_from_peer(
         # 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
-        # a bound listener on the "arbiter" addr.  the reset will be
+        # a bound listener on the registrar addr.  the reset will be
         # because the handshake was never meant took place.
         log.runtime(
             con_status
@@ -970,7 +968,7 @@ class Server(Struct):
         in `accept_addrs`.
 
         '''
-        from .._addr import (
+        from ..discovery._addr import (
             default_lo_addrs,
             wrap_address,
         )

tractor/ipc/_transport.py

@@ -54,7 +54,7 @@ from tractor.msg import (
 )
 
 if TYPE_CHECKING:
-    from tractor._addr import Address
+    from tractor.discovery._addr import Address
 
 log = get_logger()
 
@@ -225,7 +225,7 @@ class MsgpackTransport(MsgTransport):
 
                 # not sure entirely why we need this but without it we
                 # seem to be getting racy failures here on
-                # arbiter/registry name subs..
+                # registrar name subs..
                 trio.BrokenResourceError,
 
             ) as trans_err:

tractor/ipc/_uds.py

@@ -53,14 +53,14 @@ from tractor.log import get_logger
 from tractor.ipc._transport import (
     MsgpackTransport,
 )
-from tractor._state import (
+from tractor.runtime._state import (
     get_rt_dir,
     current_actor,
     is_root_process,
 )
 
 if TYPE_CHECKING:
-    from ._runtime import Actor
+    from tractor.runtime._runtime import Actor
 
 
 # Platform-specific credential passing constants

tractor/log.py

@@ -47,7 +47,7 @@ import colorlog  # type: ignore
 # import colored_traceback.auto  # ?TODO, need better config?
 import trio
 
-from ._state import current_actor
+from .runtime._state import current_actor
 
 
 _default_loglevel: str = 'ERROR'

tractor/msg/_ops.py

@@ -50,7 +50,7 @@ from tractor._exceptions import (
     _mk_recv_mte,
     pack_error,
 )
-from tractor._state import (
+from tractor.runtime._state import (
     current_ipc_ctx,
 )
 from ._codec import (

tractor/runtime/__init__.py

@@ -0,0 +1,26 @@
+# tractor: structured concurrent "actors".
+# Copyright 2018-eternity Tyler Goodlet.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+'''
+The actor runtime: core machinery for the
+actor-model implemented on a `trio` task runtime.
+
+NOTE: to avoid circular imports, this ``__init__``
+does NOT eagerly import submodules. Use direct
+module paths like ``tractor.runtime._state`` or
+``tractor.runtime._runtime`` instead.
+
+'''

tractor/runtime/_portal.py

@@ -39,30 +39,30 @@ import warnings
 
 import trio
 
-from .trionics import (
+from ..trionics import (
     maybe_open_nursery,
     collapse_eg,
 )
 from ._state import (
     current_actor,
 )
-from .ipc import Channel
-from .log import get_logger
-from .msg import (
+from ..ipc import Channel
+from ..log import get_logger
+from ..msg import (
     # Error,
     PayloadMsg,
     NamespacePath,
     Return,
 )
-from ._exceptions import (
+from .._exceptions import (
     NoResult,
     TransportClosed,
 )
-from ._context import (
+from .._context import (
     Context,
     open_context_from_portal,
 )
-from ._streaming import (
+from .._streaming import (
     MsgStream,
 )
 

tractor/runtime/_rpc.py

@@ -43,11 +43,11 @@ from trio import (
     TaskStatus,
 )
 
-from .ipc import Channel
-from ._context import (
+from ..ipc import Channel
+from .._context import (
     Context,
 )
-from ._exceptions import (
+from .._exceptions import (
     ContextCancelled,
     RemoteActorError,
     ModuleNotExposed,
@@ -56,19 +56,19 @@ from ._exceptions import (
     pack_error,
     unpack_error,
 )
-from .trionics import (
+from ..trionics import (
     collapse_eg,
     is_multi_cancelled,
     maybe_raise_from_masking_exc,
 )
-from .devx import (
+from ..devx import (
     debug,
     add_div,
     pformat as _pformat,
 )
 from . import _state
-from .log import get_logger
-from .msg import (
+from ..log import get_logger
+from ..msg import (
     current_codec,
     MsgCodec,
     PayloadT,

tractor/runtime/_runtime.py

@@ -83,46 +83,46 @@ from tractor.msg import (
     pretty_struct,
     types as msgtypes,
 )
-from .trionics import (
+from ..trionics import (
     collapse_eg,
     maybe_open_nursery,
 )
-from .ipc import (
+from ..ipc import (
     Channel,
     # IPCServer,  # causes cycles atm..
     _server,
 )
-from ._addr import (
+from ..discovery._addr import (
     UnwrappedAddress,
     Address,
     # default_lo_addrs,
     get_address_cls,
     wrap_address,
 )
-from ._context import (
+from .._context import (
     mk_context,
     Context,
 )
-from .log import get_logger
-from ._exceptions import (
+from ..log import get_logger
+from .._exceptions import (
     ContextCancelled,
     InternalError,
     ModuleNotExposed,
     MsgTypeError,
     unpack_error,
 )
-from .devx import (
+from ..devx import (
     debug,
     pformat as _pformat
 )
-from ._discovery import get_registry
+from ..discovery._discovery import get_registry
 from ._portal import Portal
 from . import _state
-from . import _mp_fixup_main
+from ..spawn import _mp_fixup_main
 from . import _rpc
 
 if TYPE_CHECKING:
-    from ._supervise import ActorNursery
+    from ._supervise import ActorNursery  # noqa
     from trio._channel import MemoryChannelState
 
 
@@ -175,13 +175,21 @@ class Actor:
     dialog.
 
     '''
-    # ugh, we need to get rid of this and replace with a "registry" sys
-    # https://github.com/goodboy/tractor/issues/216
-    is_arbiter: bool = False
+    is_registrar: bool = False
 
     @property
-    def is_registrar(self) -> bool:
-        return self.is_arbiter
+    def is_arbiter(self) -> bool:
+        '''
+        Deprecated, use `.is_registrar`.
+
+        '''
+        warnings.warn(
+            '`Actor.is_arbiter` is deprecated.\n'
+            'Use `.is_registrar` instead.',
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return self.is_registrar
 
     @property
     def is_root(self) -> bool:
@@ -237,7 +245,6 @@ class Actor:
         registry_addrs: list[Address]|None = None,
         spawn_method: str|None = None,
 
-        # TODO: remove!
         arbiter_addr: UnwrappedAddress|None = None,
 
     ) -> None:
@@ -287,8 +294,8 @@ class Actor:
             ]
 
         # marked by the process spawning backend at startup
-        # will be None for the parent most process started manually
-        # by the user (currently called the "arbiter")
+        # will be None for the parent most process started
+        # manually by the user (the "registrar")
         self._spawn_method: str = spawn_method
 
         # RPC state
@@ -907,7 +914,7 @@ class Actor:
                 # TODO! -[ ] another `Struct` for rtvs..
                 rvs: dict[str, Any] = spawnspec._runtime_vars
                 if rvs['_debug_mode']:
-                    from .devx import (
+                    from ..devx import (
                         enable_stack_on_sig,
                         maybe_init_greenback,
                     )
@@ -1656,7 +1663,7 @@ async def async_main(
                 # TODO, just read direct from ipc_server?
                 accept_addrs: list[UnwrappedAddress] = actor.accept_addrs
 
-                # Register with the arbiter if we're told its addr
+                # Register with the registrar if we're told its addr
                 log.runtime(
                     f'Registering `{actor.name}` => {pformat(accept_addrs)}\n'
                     # ^-TODO-^ we should instead show the maddr here^^
@@ -1880,153 +1887,8 @@ async def async_main(
     log.runtime(teardown_report)
 
 
-# TODO: rename to `Registry` and move to `.discovery._registry`!
-class Arbiter(Actor):
-    '''
-    A special registrar (and for now..) `Actor` who can contact all
-    other actors within its immediate process tree and possibly keeps
-    a registry of others meant to be discoverable in a distributed
-    application. Normally the registrar is also the "root actor" and
-    thus always has access to the top-most-level actor (process)
-    nursery.
-
-    By default, the registrar is always initialized when and if no
-    other registrar socket addrs have been specified to runtime
-    init entry-points (such as `open_root_actor()` or
-    `open_nursery()`). Any time a new main process is launched (and
-    thus thus a new root actor created) and, no existing registrar
-    can be contacted at the provided `registry_addr`, then a new
-    one is always created; however, if one can be reached it is
-    used.
-
-    Normally a distributed app requires at least registrar per
-    logical host where for that given "host space" (aka localhost
-    IPC domain of addresses) it is responsible for making all other
-    host (local address) bound actors *discoverable* to external
-    actor trees running on remote hosts.
-
-    '''
-    is_arbiter = True
-
-    # TODO, implement this as a read on there existing a `._state` of
-    # some sort setup by whenever we impl this all as
-    # a `.discovery._registry.open_registry()` API
-    def is_registry(self) -> bool:
-        return self.is_arbiter
-
-    def __init__(
-        self,
-        *args,
-        **kwargs,
-    ) -> None:
-
-        self._registry: dict[
-            tuple[str, str],
-            UnwrappedAddress,
-        ] = {}
-        self._waiters: dict[
-            str,
-            # either an event to sync to receiving an actor uid (which
-            # is filled in once the actor has sucessfully registered),
-            # or that uid after registry is complete.
-            list[trio.Event | tuple[str, str]]
-        ] = {}
-
-        super().__init__(*args, **kwargs)
-
-    async def find_actor(
-        self,
-        name: str,
-
-    ) -> UnwrappedAddress|None:
-
-        for uid, addr in self._registry.items():
-            if name in uid:
-                return addr
-
-        return None
-
-    async def get_registry(
-        self
-
-    ) -> dict[str, UnwrappedAddress]:
-        '''
-        Return current name registry.
-
-        This method is async to allow for cross-actor invocation.
-
-        '''
-        # NOTE: requires ``strict_map_key=False`` to the msgpack
-        # unpacker since we have tuples as keys (not this makes the
-        # arbiter suscetible to hashdos):
-        # https://github.com/msgpack/msgpack-python#major-breaking-changes-in-msgpack-10
-        return {
-            '.'.join(key): val
-            for key, val in self._registry.items()
-        }
-
-    async def wait_for_actor(
-        self,
-        name: str,
-
-    ) -> list[UnwrappedAddress]:
-        '''
-        Wait for a particular actor to register.
-
-        This is a blocking call if no actor by the provided name is currently
-        registered.
-
-        '''
-        addrs: list[UnwrappedAddress] = []
-        addr: UnwrappedAddress
-
-        mailbox_info: str = 'Actor registry contact infos:\n'
-        for uid, addr in self._registry.items():
-            mailbox_info += (
-                f'|_uid: {uid}\n'
-                f'|_addr: {addr}\n\n'
-            )
-            if name == uid[0]:
-                addrs.append(addr)
-
-        if not addrs:
-            waiter = trio.Event()
-            self._waiters.setdefault(name, []).append(waiter)
-            await waiter.wait()
-
-            for uid in self._waiters[name]:
-                if not isinstance(uid, trio.Event):
-                    addrs.append(self._registry[uid])
-
-        log.runtime(mailbox_info)
-        return addrs
-
-    async def register_actor(
-        self,
-        uid: tuple[str, str],
-        addr: UnwrappedAddress
-    ) -> None:
-        uid = name, hash = (str(uid[0]), str(uid[1]))
-        waddr: Address = wrap_address(addr)
-        if not waddr.is_valid:
-            # should never be 0-dynamic-os-alloc
-            await debug.pause()
-
-        self._registry[uid] = addr
-
-        # pop and signal all waiter events
-        events = self._waiters.pop(name, [])
-        self._waiters.setdefault(name, []).append(uid)
-        for event in events:
-            if isinstance(event, trio.Event):
-                event.set()
-
-    async def unregister_actor(
-        self,
-        uid: tuple[str, str]
-
-    ) -> None:
-        uid = (str(uid[0]), str(uid[1]))
-        entry: tuple = self._registry.pop(uid, None)
-        if entry is None:
-            log.warning(f'Request to de-register {uid} failed?')
+# Backward compat: class moved to discovery._registry
+from ..discovery._registry import (
+    Registrar as Registrar,
+)
+Arbiter = Registrar

tractor/runtime/_state.py

@@ -25,6 +25,7 @@ from contextvars import (
 from pathlib import Path
 from typing import (
     Any,
+    Callable,
     Literal,
     TYPE_CHECKING,
 )
@@ -32,9 +33,14 @@ from typing import (
 import platformdirs
 from trio.lowlevel import current_task
 
+from msgspec import (
+    field,
+    Struct,
+)
+
 if TYPE_CHECKING:
     from ._runtime import Actor
-    from ._context import Context
+    from .._context import Context
 
 
 # default IPC transport protocol settings
@@ -47,9 +53,70 @@ _def_tpt_proto: TransportProtocolKey = 'tcp'
 _current_actor: Actor|None = None  # type: ignore # noqa
 _last_actor_terminated: Actor|None = None
 
+
 # TODO: mk this a `msgspec.Struct`!
-# -[ ] type out all fields obvi!
+# -[x] type out all fields obvi!
 # -[ ] (eventually) mk wire-ready for monitoring?
+class RuntimeVars(Struct):
+    '''
+    Actor-(and thus process)-global runtime state.
+
+    This struct is relayed from parent to child during sub-actor
+    spawning and is a singleton instance per process.
+
+    Generally contains,
+    - root-actor indicator.
+    - comms-info: addrs for both (public) process/service-discovery
+      and in-tree contact with other actors.
+    - transport-layer IPC protocol server(s) settings.
+    - debug-mode settings for enabling sync breakpointing and any
+      surrounding REPL-fixture hooking.
+    - infected-`asyncio` via guest-mode toggle(s)/cohfig.
+
+    '''
+    _is_root: bool = False  # bool
+    _root_mailbox: tuple[str, str|int] = (None, None)  # tuple[str|None, str|None]
+    _root_addrs: list[
+        tuple[str, str|int],
+    ] = []  # tuple[str|None, str|None]
+
+    # parent->chld ipc protocol caps
+    _enable_tpts: list[TransportProtocolKey] = field(
+        default_factory=lambda: [_def_tpt_proto],
+    )
+
+    # registrar info
+    _registry_addrs: list[tuple] = []
+
+    # `debug_mode: bool` settings
+    _debug_mode: bool = False  # bool
+    repl_fixture: bool|Callable = False  # |AbstractContextManager[bool]
+    # for `tractor.pause_from_sync()` & `breakpoint()` support
+    use_greenback: bool = False
+
+    # infected-`asyncio`-mode: `trio` running as guest.
+    _is_infected_aio: bool = False
+
+    def __setattr__(
+        self,
+        key,
+        val,
+    ) -> None:
+        breakpoint()
+        super().__setattr__(key, val)
+
+    def update(
+        self,
+        from_dict: dict|Struct,
+    ) -> None:
+        for attr, val in from_dict.items():
+            setattr(
+                self,
+                attr,
+                val,
+            )
+
+
 _runtime_vars: dict[str, Any] = {
     # root of actor-process tree info
     '_is_root': False,  # bool
@@ -73,6 +140,23 @@ _runtime_vars: dict[str, Any] = {
 }
 
 
+def get_runtime_vars(
+    as_dict: bool = True,
+) -> dict:
+    '''
+    Deliver a **copy** of the current `Actor`'s "runtime variables".
+
+    By default, for historical impl reasons, this delivers the `dict`
+    form, but the `RuntimeVars` struct should be utilized as possible
+    for future calls.
+
+    '''
+    if as_dict:
+        return dict(_runtime_vars)
+
+    return RuntimeVars(**_runtime_vars)
+
+
 def last_actor() -> Actor|None:
     '''
     Try to return last active `Actor` singleton
@@ -98,7 +182,7 @@ def current_actor(
         _current_actor is None
     ):
         msg: str = 'No local actor has been initialized yet?\n'
-        from ._exceptions import NoRuntime
+        from .._exceptions import NoRuntime
 
         if last := last_actor():
             msg += (
@@ -164,7 +248,7 @@ def current_ipc_ctx(
         not ctx
         and error_on_not_set
     ):
-        from ._exceptions import InternalError
+        from .._exceptions import InternalError
         raise InternalError(
             'No IPC context has been allocated for this task yet?\n'
             f'|_{current_task()}\n'

tractor/runtime/_supervise.py

@@ -30,36 +30,36 @@ import warnings
 import trio
 
 
-from .devx import (
+from ..devx import (
     debug,
     pformat as _pformat,
 )
-from ._addr import (
+from ..discovery._addr import (
     UnwrappedAddress,
     mk_uuid,
 )
 from ._state import current_actor, is_main_process
-from .log import get_logger, get_loglevel
+from ..log import get_logger, get_loglevel
 from ._runtime import Actor
 from ._portal import Portal
-from .trionics import (
+from ..trionics import (
     is_multi_cancelled,
     collapse_eg,
 )
-from ._exceptions import (
+from .._exceptions import (
     ContextCancelled,
 )
-from ._root import (
+from .._root import (
     open_root_actor,
 )
 from . import _state
-from . import _spawn
+from ..spawn import _spawn
 
 
 if TYPE_CHECKING:
     import multiprocessing as mp
-    # from .ipc._server import IPCServer
-    from .ipc import IPCServer
+    # from ..ipc._server import IPCServer
+    from ..ipc import IPCServer
 
 
 log = get_logger()

tractor/spawn/__init__.py

@@ -0,0 +1,26 @@
+# tractor: structured concurrent "actors".
+# Copyright 2018-eternity Tyler Goodlet.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+'''
+Actor process spawning machinery using
+multiple backends (trio, multiprocessing).
+
+NOTE: to avoid circular imports, this ``__init__``
+does NOT eagerly import submodules. Use direct
+module paths like ``tractor.spawn._spawn`` or
+``tractor.spawn._entry`` instead.
+
+'''

tractor/spawn/_entry.py

@@ -29,19 +29,19 @@ from typing import (
 
 import trio  # type: ignore
 
-from .log import (
+from ..log import (
     get_console_log,
     get_logger,
 )
-from . import _state
-from .devx import (
+from ..runtime import _state
+from ..devx import (
     _frame_stack,
     pformat,
 )
-# from .msg import pretty_struct
-from .to_asyncio import run_as_asyncio_guest
-from ._addr import UnwrappedAddress
-from ._runtime import (
+# from ..msg import pretty_struct
+from ..to_asyncio import run_as_asyncio_guest
+from ..discovery._addr import UnwrappedAddress
+from ..runtime._runtime import (
     async_main,
     Actor,
 )

tractor/spawn/_forkserver_override.py

@@ -125,7 +125,7 @@ class PatchedForkServer(ForkServer):
                 self._forkserver_pid = None
 
             # XXX only thing that changed!
-            cmd = ('from tractor._forkserver_override import main; ' +
+            cmd = ('from tractor.spawn._forkserver_override import main; ' +
                    'main(%d, %d, %r, **%r)')
 
             if self._preload_modules:

tractor/spawn/_spawn.py

@@ -34,11 +34,11 @@ from typing import (
 import trio
 from trio import TaskStatus
 
-from .devx import (
+from ..devx import (
     debug,
     pformat as _pformat
 )
-from tractor._state import (
+from tractor.runtime._state import (
     current_actor,
     is_main_process,
     is_root_process,
@@ -46,10 +46,10 @@ from tractor._state import (
     _runtime_vars,
 )
 from tractor.log import get_logger
-from tractor._addr import UnwrappedAddress
-from tractor._portal import Portal
-from tractor._runtime import Actor
-from tractor._entry import _mp_main
+from tractor.discovery._addr import UnwrappedAddress
+from tractor.runtime._portal import Portal
+from tractor.runtime._runtime import Actor
+from ._entry import _mp_main
 from tractor._exceptions import ActorFailure
 from tractor.msg import (
     types as msgtypes,
@@ -58,11 +58,11 @@ from tractor.msg import (
 
 
 if TYPE_CHECKING:
-    from ipc import (
+    from tractor.ipc import (
         _server,
         Channel,
     )
-    from ._supervise import ActorNursery
+    from tractor.runtime._supervise import ActorNursery
     ProcessType = TypeVar('ProcessType', mp.Process, trio.Process)
 
 

tractor/to_asyncio.py

@@ -43,7 +43,7 @@ from tractor._exceptions import (
     AsyncioTaskExited,
     AsyncioCancelled,
 )
-from tractor._state import (
+from tractor.runtime._state import (
     debug_mode,
     _runtime_vars,
 )

tractor/trionics/_mngrs.py

@@ -35,7 +35,7 @@ from typing import (
 )
 
 import trio
-from tractor._state import current_actor
+from tractor.runtime._state import current_actor
 from tractor.log import get_logger
 from ._tn import maybe_open_nursery
 # from ._beg import collapse_eg

uv.lock

@@ -273,11 +273,11 @@ wheels = [
 
 [[package]]
 name = "pygments"
-version = "2.19.2"
+version = "2.20.0"
 source = { registry = "https://pypi.org/simple" }
-sdist = { url = "https://files.pythonhosted.org/packages/b0/77/a5b8c569bf593b0140bde72ea885a803b82086995367bf2037de0159d924/pygments-2.19.2.tar.gz", hash = "sha256:636cb2477cec7f8952536970bc533bc43743542f70392ae026374600add5b887", size = 4968631, upload-time = "2025-06-21T13:39:12.283Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/c3/b2/bc9c9196916376152d655522fdcebac55e66de6603a76a02bca1b6414f6c/pygments-2.20.0.tar.gz", hash = "sha256:6757cd03768053ff99f3039c1a36d6c0aa0b263438fcab17520b30a303a82b5f", size = 4955991, upload-time = "2026-03-29T13:29:33.898Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/c7/21/705964c7812476f378728bdf590ca4b771ec72385c533964653c68e86bdc/pygments-2.19.2-py3-none-any.whl", hash = "sha256:86540386c03d588bb81d44bc3928634ff26449851e99741617ecb9037ee5ec0b", size = 1225217, upload-time = "2025-06-21T13:39:07.939Z" },
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