circuitpython/tests/extmod/uasyncio_gather_notimpl.py
Damien George 90aaf2dbef extmod/uasyncio: Fix gather cancelling and handling of exceptions.
The following fixes are made:
- cancelling a gather now cancels all sub-tasks of the gather (previously
  it would only cancel the first)
- if any sub-task of a gather raises an exception then the gather finishes
  (previously it would only finish if the first sub-task raised)

Fixes issues #5798, #7807, #7901.

Signed-off-by: Damien George <damien@micropython.org>
2022-03-30 16:07:44 +11:00

54 lines
1.3 KiB
Python

# Test uasyncio.gather() function, features that are not implemented.
try:
import uasyncio as asyncio
except ImportError:
try:
import asyncio
except ImportError:
print("SKIP")
raise SystemExit
def custom_handler(loop, context):
print(repr(context["exception"]))
async def task(id):
print("task start", id)
await asyncio.sleep(0.01)
print("task end", id)
return id
async def gather_task(t0, t1):
print("gather_task start")
await asyncio.gather(t0, t1)
print("gather_task end")
async def main():
loop = asyncio.get_event_loop()
loop.set_exception_handler(custom_handler)
# Test case where can't wait on a task being gathered.
tasks = [asyncio.create_task(task(1)), asyncio.create_task(task(2))]
gt = asyncio.create_task(gather_task(tasks[0], tasks[1]))
await asyncio.sleep(0) # let the gather start
try:
await tasks[0] # can't await because this task is part of the gather
except RuntimeError as er:
print(repr(er))
await gt
print("====")
# Test case where can't gather on a task being waited.
tasks = [asyncio.create_task(task(1)), asyncio.create_task(task(2))]
asyncio.create_task(gather_task(tasks[0], tasks[1]))
await tasks[0] # wait on this task before the gather starts
await tasks[1]
asyncio.run(main())