tests/extmod: Add uasyncio tests.

All .exp files are included because they require CPython 3.8 which may not
always be available.

1 files changed, 55 insertions, 0 deletions

diff --git a/tests/extmod/uasyncio_lock_cancel.py b/tests/extmod/uasyncio_lock_cancel.py
new file mode 100644
index 000000000..85b8df848
--- /dev/null
+++ b/tests/extmod/uasyncio_lock_cancel.py
@@ -0,0 +1,55 @@
+# Test that locks work when cancelling multiple waiters on the lock
+
+try:
+    import uasyncio as asyncio
+except ImportError:
+    try:
+        import asyncio
+    except ImportError:
+        print("SKIP")
+        raise SystemExit
+
+
+async def task(i, lock, lock_flag):
+    print("task", i, "start")
+    try:
+        await lock.acquire()
+    except asyncio.CancelledError:
+        print("task", i, "cancel")
+        return
+    print("task", i, "lock_flag", lock_flag[0])
+    lock_flag[0] = True
+    await asyncio.sleep(0)
+    lock.release()
+    lock_flag[0] = False
+    print("task", i, "done")
+
+
+async def main():
+    # Create a lock and acquire it so the tasks below must wait
+    lock = asyncio.Lock()
+    await lock.acquire()
+    lock_flag = [True]
+
+    # Create 4 tasks and let them all run
+    t0 = asyncio.create_task(task(0, lock, lock_flag))
+    t1 = asyncio.create_task(task(1, lock, lock_flag))
+    t2 = asyncio.create_task(task(2, lock, lock_flag))
+    t3 = asyncio.create_task(task(3, lock, lock_flag))
+    await asyncio.sleep(0)
+
+    # Cancel 2 of the tasks (which are waiting on the lock) and release the lock
+    t1.cancel()
+    t2.cancel()
+    lock.release()
+    lock_flag[0] = False
+
+    # Let the tasks run to completion
+    for _ in range(4):
+        await asyncio.sleep(0)
+
+    # The locke should be unlocked
+    print(lock.locked())
+
+
+asyncio.run(main())