Add (first-draft) infected-`asyncio` actor task uses debugger example

examples/debugging/asyncio_bp.py

@@ -0,0 +1,79 @@
+import asyncio
+
+import trio
+import tractor
+
+
+async def bp_then_error(
+    to_trio: trio.MemorySendChannel,
+    from_trio: asyncio.Queue,
+
+) -> None:
+
+    # sync with ``trio``-side (caller) task
+    to_trio.send_nowait('start')
+
+    # NOTE: what happens here inside the hook needs some refinement..
+    # => seems like it's still `._debug._set_trace()` but
+    #    we set `Lock.local_task_in_debug = 'sync'`, we probably want
+    #    some further, at least, meta-data about the task/actoq in debug
+    #    in terms of making it clear it's asyncio mucking about.
+
+    breakpoint()
+
+    await asyncio.sleep(0.5)
+    raise ValueError('blah')
+
+
+async def aio_sleep_forever():
+    await asyncio.sleep(float('inf'))
+
+
+@tractor.context
+async def trio_ctx(
+    ctx: tractor.Context,
+):
+
+    # this will block until the ``asyncio`` task sends a "first"
+    # message, see first line in above func.
+    async with (
+        tractor.to_asyncio.open_channel_from(bp_then_error) as (first, chan),
+        trio.open_nursery() as n,
+    ):
+
+        assert first == 'start'
+        await ctx.started(first)
+
+        n.start_soon(
+            tractor.to_asyncio.run_task,
+            aio_sleep_forever,
+        )
+        await trio.sleep_forever()
+
+
+async def main():
+
+    async with tractor.open_nursery() as n:
+
+        p = await n.start_actor(
+            'aio_daemon',
+            enable_modules=[__name__],
+            infect_asyncio=True,
+            debug_mode=True,
+            loglevel='cancel',
+        )
+
+        async with p.open_context(trio_ctx) as (ctx, first):
+
+            assert first == 'start'
+            await trio.sleep_forever()
+
+            assert 0
+
+        # TODO: case where we cancel from trio-side while asyncio task
+        # has debugger lock?
+        # await p.cancel_actor()
+
+
+if __name__ == '__main__':
+    trio.run(main)