Provision for infected-`asyncio` debug mode support

It's **almost** there, we're just missing the final translation code to
get from an `asyncio` side task to be able to call
`.devx._debug..wait_for_parent_stdin_hijack()` to do root actor TTY
locking. Then we just need to ensure internals also do the right thing
with `greenback()` for equivalent sync `breakpoint()` style pause
points.

Since i'm deferring this until later, tossing in some xfail tests to
`test_infected_asyncio` with TODOs for the needed implementation as well
as eventual test org.

By "provision" it means we add:
- `greenback` init block to `_run_asyncio_task()` when debug mode is
  enabled (but which will currently rte when `asyncio` is detected)
  using `.bestow_portal()` around the `asyncio.Task`.
- a call to `_debug.maybe_init_greenback()` in the `run_as_asyncio_guest()`
  guest-mode entry point.
- as part of `._debug.Lock.is_main_trio_thread()` whenever the async-lib
  is not 'trio' error lock the backend name (which is obvi `'asyncio'`
  in this use case).

examples/debugging/asyncio_bp.py

@@ -77,7 +77,9 @@ async def main(
 
 ) -> None:
 
-    async with tractor.open_nursery() as n:
+    async with tractor.open_nursery(
+        # debug_mode=True,
+    ) as n:
 
         p = await n.start_actor(
             'aio_daemon',

tests/test_infected_asyncio.py

@@ -601,7 +601,8 @@ def test_echoserver_detailed_mechanics(
                             pass
                         else:
                             pytest.fail(
-                                "stream wasn't stopped after sentinel?!")
+                                'stream not stopped after sentinel ?!'
+                            )
 
             # TODO: the case where this blocks and
             # is cancelled by kbi or out of task cancellation
@@ -613,3 +614,37 @@ def test_echoserver_detailed_mechanics(
 
     else:
         trio.run(main)
+
+
+# TODO: debug_mode tests once we get support for `asyncio`!
+#
+# -[ ] need tests to wrap both scripts:
+#   - [ ] infected_asyncio_echo_server.py
+#   - [ ] debugging/asyncio_bp.py
+#  -[ ] consider moving ^ (some of) these ^ to `test_debugger`?
+#
+# -[ ] missing impl outstanding includes:
+#  - [x] for sync pauses we need to ensure we open yet another
+#    `greenback` portal in the asyncio task
+#    => completed using `.bestow_portal(task)` inside
+#     `.to_asyncio._run_asyncio_task()` right?
+#   -[ ] translation func to get from `asyncio` task calling to 
+#     `._debug.wait_for_parent_stdin_hijack()` which does root
+#     call to do TTY locking.
+#
+def test_sync_breakpoint():
+    '''
+    Verify we can do sync-func/code breakpointing using the
+    `breakpoint()` builtin inside infected mode actors.
+
+    '''
+    pytest.xfail('This support is not implemented yet!')
+
+
+def test_debug_mode_crash_handling():
+    '''
+    Verify mult-actor crash handling works with a combo of infected-`asyncio`-mode
+    and normal `trio` actors despite nested process trees.
+
+    '''
+    pytest.xfail('This support is not implemented yet!')

tractor/devx/_debug.py

@@ -187,13 +187,18 @@ class Lock:
         `trio.to_thread.run_sync()`.
 
         '''
-        return (
+        is_trio_main = (
             # TODO: since this is private, @oremanj says
             # we should just copy the impl for now..
             trio._util.is_main_thread()
             and
-            sniffio.current_async_library() == 'trio'
+            (async_lib := sniffio.current_async_library()) == 'trio'
         )
+        if not is_trio_main:
+            log.warning(
+                f'Current async-lib detected by `sniffio`: {async_lib}\n'
+            )
+        return is_trio_main
         # XXX apparently unreliable..see ^
         # (
         #     threading.current_thread()
@@ -1114,6 +1119,14 @@ def pause_from_sync(
             '- `async with tractor.open_root_actor()`\n'
         )
 
+    # NOTE: once supported, remove this AND the one
+    # inside `._pause()`!
+    if actor.is_infected_aio():
+        raise RuntimeError(
+            '`tractor.pause[_from_sync]()` not yet supported '
+            'for infected `asyncio` mode!'
+        )
+
     # raises on not-found by default
     greenback: ModuleType = maybe_import_greenback()
     mdb: MultiActorPdb = mk_mpdb()

tractor/to_asyncio.py

@@ -33,10 +33,14 @@ from typing import (
 import trio
 from outcome import Error
 
-from .log import get_logger
+from tractor.log import get_logger
-from ._state import current_actor
+from tractor._state import (
-from ._exceptions import AsyncioCancelled
+    current_actor,
-from .trionics._broadcast import (
+    debug_mode,
+)
+from tractor.devx import _debug
+from tractor._exceptions import AsyncioCancelled
+from tractor.trionics._broadcast import (
     broadcast_receiver,
     BroadcastReceiver,
 )
@@ -158,7 +162,9 @@ def _run_asyncio_task(
     '''
     __tracebackhide__ = True
     if not current_actor().is_infected_aio():
-        raise RuntimeError("`infect_asyncio` mode is not enabled!?")
+        raise RuntimeError(
+            "`infect_asyncio` mode is not enabled!?"
+        )
 
     # ITC (inter task comms), these channel/queue names are mostly from
     # ``asyncio``'s perspective.
@@ -253,7 +259,7 @@ def _run_asyncio_task(
     if not inspect.isawaitable(coro):
         raise TypeError(f"No support for invoking {coro}")
 
-    task = asyncio.create_task(
+    task: asyncio.Task = asyncio.create_task(
         wait_on_coro_final_result(
             to_trio,
             coro,
@@ -262,6 +268,18 @@ def _run_asyncio_task(
     )
     chan._aio_task = task
 
+    # XXX TODO XXX get this actually workin.. XD
+    # maybe setup `greenback` for `asyncio`-side task REPLing
+    if (
+        debug_mode()
+        and
+        (greenback := _debug.maybe_import_greenback(
+            force_reload=True,
+            raise_not_found=False,
+        ))
+    ):
+        greenback.bestow_portal(task)
+
     def cancel_trio(task: asyncio.Task) -> None:
         '''
         Cancel the calling ``trio`` task on error.
@@ -531,6 +549,16 @@ def run_as_asyncio_guest(
         loop = asyncio.get_running_loop()
         trio_done_fut = asyncio.Future()
 
+        if debug_mode():
+            # XXX make it obvi we know this isn't supported yet!
+            log.error(
+                'Attempting to enter unsupported `greenback` init '
+                'from `asyncio` task..'
+            )
+            await _debug.maybe_init_greenback(
+                force_reload=True,
+            )
+
         def trio_done_callback(main_outcome):
 
             if isinstance(main_outcome, Error):