✅ make test_depends_deadlock more co-operative

This ensures that the threads which are blocking up the threadpool eventually exit when in failure mode.

tests/test_depends_deadlock.py

@@ -1,5 +1,4 @@
 import asyncio
-import multiprocessing
 import threading
 import time
 from collections.abc import Iterator
@@ -36,36 +35,14 @@ class Item(BaseModel):
 # of the model and the cleanup of the Depends
 @app.get("/deadlock", response_model=Item)
 def get_deadlock(dep: None = Depends(release_resource)) -> Item:
-    mutex.acquire()
+    mutex.acquire(timeout=10)
     return Item(name="foo", id=1)
 
 
-# NOTE: the failure mode here can cause the test suite to hang.
-# Since the default threadpool is a global which is not easily patched
-# (and doing so would make the test somewhat fragile/pointless)
-# we need to use a subprocess to isolate the bad behaviour.
-# If you are struggling to debug, comment out this function and rename
-# the impl_ version to test_depends_deadlock
-def test_depends_deadlock() -> None:
-
-    proc = multiprocessing.Process(target=impl_test_depends_deadlock, daemon=True)
-    proc.start()
-    proc.join(timeout=10)
-
-    try:
-        assert not proc.is_alive(), (
-            "Process is still alive after timeout, likely due to a deadlock"
-        )
-    finally:
-        proc.kill()  # Ensure the process is terminated if it's still alive
-
-    assert proc.exitcode == 0, "Process did not exit cleanly, see logs for details"
-
-
 # Fire off 100 requests in parallel(ish) in order to create contention
 # over the shared resource (simulating a fastapi server that interacts with
 # a database connection pool).
-def impl_test_depends_deadlock() -> None:
+def test_depends_deadlock() -> None:
     async def make_request(client: AsyncClient):
         await client.get("/deadlock")