Move debugger wait inside OCA nursery

If the root calls `trio.Process.kill()` on immediate child proc teardown
when the child is using pdb, we can get stdstreams clobbering that
results in a pdb++ repl where the user can't see what's been typed. Not
killing such children on cancellation / error seems to resolve this
issue whilst still giving reliable termination. For now, code that
special path until a time it becomes a problem for ensuring zombie
reaps.

tests/test_2way.py

@@ -52,9 +52,14 @@ async def assert_state(value: bool):
     assert _state == value
 
 
-def test_simple_contex():
+@pytest.mark.parametrize(
+    'error_parent',
+    [False, True],
+)
+def test_simple_context(error_parent):
 
     async def main():
+
         async with tractor.open_nursery() as n:
 
             portal = await n.start_actor(
@@ -74,10 +79,19 @@ def test_simple_contex():
             # after cancellation
             await portal.run(assert_state, value=False)
 
+            if error_parent:
+                raise ValueError
+
             # shut down daemon
             await portal.cancel_actor()
 
-    trio.run(main)
+    if error_parent:
+        try:
+            trio.run(main)
+        except ValueError:
+            pass
+    else:
+        trio.run(main)
 
 
 @tractor.context

tests/test_advanced_streaming.py

@@ -140,3 +140,81 @@ def test_dynamic_pub_sub():
         trio.run(main)
     except trio.TooSlowError:
         pass
+
+
+@tractor.context
+async def one_task_streams_and_one_handles_reqresp(
+
+    ctx: tractor.Context,
+
+) -> None:
+
+    await ctx.started()
+
+    async with ctx.open_stream() as stream:
+
+        async def pingpong():
+            '''Run a simple req/response service.
+
+            '''
+            async for msg in stream:
+                print('rpc server ping')
+                assert msg == 'ping'
+                print('rpc server pong')
+                await stream.send('pong')
+
+        async with trio.open_nursery() as n:
+            n.start_soon(pingpong)
+
+            for _ in itertools.count():
+                await stream.send('yo')
+                await trio.sleep(0.01)
+
+
+def test_reqresp_ontopof_streaming():
+    '''Test a subactor that both streams with one task and
+    spawns another which handles a small requests-response
+    dialogue over the same bidir-stream.
+
+    '''
+    async def main():
+
+        with trio.move_on_after(2):
+            async with tractor.open_nursery() as n:
+
+                # name of this actor will be same as target func
+                portal = await n.start_actor(
+                    'dual_tasks',
+                    enable_modules=[__name__]
+                )
+
+                # flat to make sure we get at least one pong
+                got_pong: bool = False
+
+                async with portal.open_context(
+                    one_task_streams_and_one_handles_reqresp,
+
+                ) as (ctx, first):
+
+                    assert first is None
+
+                    async with ctx.open_stream() as stream:
+
+                        await stream.send('ping')
+
+                        async for msg in stream:
+                            print(f'client received: {msg}')
+
+                            assert msg in {'pong', 'yo'}
+
+                            if msg == 'pong':
+                                got_pong = True
+                                await stream.send('ping')
+                                print('client sent ping')
+
+        assert got_pong
+
+    try:
+        trio.run(main)
+    except trio.TooSlowError:
+        pass

tractor/_actor.py

@@ -479,7 +479,7 @@ class Actor:
         try:
             send_chan, recv_chan = self._cids2qs[(actorid, cid)]
         except KeyError:
-            send_chan, recv_chan = trio.open_memory_channel(1000)
+            send_chan, recv_chan = trio.open_memory_channel(2*10)
             send_chan.cid = cid  # type: ignore
             recv_chan.cid = cid  # type: ignore
             self._cids2qs[(actorid, cid)] = send_chan, recv_chan
@@ -528,11 +528,14 @@ class Actor:
                 task_status.started(loop_cs)
                 async for msg in chan:
                     if msg is None:  # loop terminate sentinel
+
                         log.debug(
                             f"Cancelling all tasks for {chan} from {chan.uid}")
-                        for (channel, cid) in self._rpc_tasks:
+
+                        for (channel, cid) in self._rpc_tasks.copy():
                             if channel is chan:
                                 await self._cancel_task(cid, channel)
+
                         log.debug(
                                 f"Msg loop signalled to terminate for"
                                 f" {chan} from {chan.uid}")

tractor/_portal.py

@@ -359,6 +359,7 @@ class Portal:
         fn_mod_path, fn_name = func_deats(func)
 
 
+        recv_chan: trio.ReceiveMemoryChannel = None
         try:
             cid, recv_chan, functype, first_msg = await self._submit(
                 fn_mod_path, fn_name, kwargs)
@@ -390,7 +391,8 @@ class Portal:
                 await ctx.cancel()
 
         finally:
-            await recv_chan.aclose()
+            if recv_chan is not None:
+                await recv_chan.aclose()
 
 @dataclass
 class LocalPortal:

tractor/_spawn.py

@@ -339,6 +339,7 @@ async def new_proc(
             bind_addr=bind_addr,
             parent_addr=parent_addr,
             _runtime_vars=_runtime_vars,
+            infect_asyncio=infect_asyncio,
             task_status=task_status,
         )
 
@@ -354,6 +355,7 @@ async def mp_new_proc(
     parent_addr: Tuple[str, int],
     _runtime_vars: Dict[str, Any],  # serialized and sent to _child
     *,
+    infect_asyncio: bool = False,
     task_status: TaskStatus[Portal] = trio.TASK_STATUS_IGNORED
 
 ) -> None:

tractor/_trionics.py

@@ -12,7 +12,7 @@ import trio
 from async_generator import asynccontextmanager
 
 from . import _debug
-from ._state import current_actor, is_main_process
+from ._state import current_actor, is_main_process, is_root_process
 from .log import get_logger, get_loglevel
 from ._actor import Actor
 from ._portal import Portal
@@ -263,6 +263,26 @@ async def _open_and_supervise_one_cancels_all_nursery(
                         "to complete"
                     )
                 except BaseException as err:
+
+                    if is_root_process() and (
+                        type(err) in {
+                            Exception, trio.MultiError, trio.Cancelled
+                        }
+                    ):
+                        # if we error in the root but the debugger is
+                        # engaged we don't want to prematurely kill (and
+                        # thus clobber access to) the local tty streams.
+                        # instead try to wait for pdb to be released before
+                        # tearing down.
+                        debug_complete = _debug._pdb_complete
+                        if debug_complete and not debug_complete.is_set():
+                            log.warning(
+                                "Root has errored but pdb is active..waiting "
+                                "on debug lock")
+                            await _debug._pdb_complete.wait()
+
+                        # raise
+
                     # if the caller's scope errored then we activate our
                     # one-cancels-all supervisor strategy (don't
                     # worry more are coming).
@@ -377,26 +397,11 @@ async def open_nursery(
             async with open_root_actor(**kwargs) as actor:
                 assert actor is current_actor()
 
-                try:
-                    async with _open_and_supervise_one_cancels_all_nursery(
-                        actor
-                    ) as anursery:
-                        yield anursery
-
-                except (Exception, trio.MultiError, trio.Cancelled):
-                    # if we error in the root but the debugger is
-                    # engaged we don't want to prematurely kill (and
-                    # thus clobber access to) the local tty streams.
-                    # instead try to wait for pdb to be released before
-                    # tearing down.
-                    if not _debug._pdb_complete.is_set():
-                        log.warning(
-                            "Root has errored but pdb is active..waiting "
-                            "on debug lock")
-                        with trio.CancelScope(shield=True):
-                            await _debug._pdb_complete.wait()
-
-                    raise
+                # try:
+                async with _open_and_supervise_one_cancels_all_nursery(
+                    actor
+                ) as anursery:
+                    yield anursery
 
         else:  # sub-nursery case
 

tractor/to_asyncio.py

@@ -101,14 +101,16 @@ def _run_asyncio_task(
         """Cancel the calling ``trio`` task on error.
         """
         nonlocal aio_err
-        aio_err = task.exception()
+        try:
+            aio_err = task.exception()
+        except asyncio.CancelledError as cerr:
+            aio_err = cerr
 
         if aio_err:
             log.exception(f"asyncio task errorred:\n{aio_err}")
 
         # cancel_scope.cancel()
         from_aio._err = aio_err
-        to_trio.close()
 
     task.add_done_callback(cancel_trio)
 
@@ -233,17 +235,25 @@ async def run_task(
         #         raise aio_err
 
     # Do we need this?
-    except BaseException as err:
+    except Exception as err:
         # await tractor.breakpoint()
         aio_err = from_aio._err
+
+        # try:
         if aio_err is not None:
             # always raise from any captured asyncio error
             raise err from aio_err
         else:
             raise
+        # finally:
+        #     if not task.done():
+        #         task.cancel()
 
-    finally:
-        task.cancel()
+    except trio.Cancelled:
+        if not task.done():
+            task.cancel()
+
+        raise
 
 
 # async def stream_from_task