mirror of
https://github.com/licsber/micropython.git
synced 2024-09-20 09:00:23 +08:00
ca40eb0fda
When a tasks raises an exception which is uncaught, and no other task await's on that task, then an error message is printed (or a user function called) via a call to Loop.call_exception_handler. In CPython this call is made when the Task object is freed (eg via reference counting) because it's at that point that it is known that the exception that was raised will never be handled. MicroPython does not have reference counting and the current behaviour is to deal with uncaught exceptions as early as possible, ie as soon as they terminate the task. But this can be undesirable because in certain cases a task can start and raise an exception immediately (before any await is executed in that task's coro) and before any other task gets a chance to await on it to catch the exception. This commit changes the behaviour so that tasks which end due to an uncaught exception are scheduled one more time for execution, and if they are not await'ed on by the next scheduling loop, then the exception handler is called (eg the exception is printed out). Signed-off-by: Damien George <damien@micropython.org>
57 lines
1.3 KiB
Python
57 lines
1.3 KiB
Python
# Test that tasks return their value correctly to the caller
|
|
|
|
try:
|
|
import uasyncio as asyncio
|
|
except ImportError:
|
|
try:
|
|
import asyncio
|
|
except ImportError:
|
|
print("SKIP")
|
|
raise SystemExit
|
|
|
|
|
|
def custom_handler(loop, context):
|
|
print("custom_handler", repr(context["exception"]))
|
|
|
|
|
|
async def task(i):
|
|
# Raise with 2 args so exception prints the same in uPy and CPython
|
|
raise ValueError(i, i + 1)
|
|
|
|
|
|
async def main():
|
|
loop = asyncio.get_event_loop()
|
|
|
|
# Check default exception handler, should be None
|
|
print(loop.get_exception_handler())
|
|
|
|
# Set exception handler and test it was set
|
|
loop.set_exception_handler(custom_handler)
|
|
print(loop.get_exception_handler() == custom_handler)
|
|
|
|
# Create a task that raises and uses the custom exception handler
|
|
asyncio.create_task(task(0))
|
|
print("sleep")
|
|
for _ in range(2):
|
|
await asyncio.sleep(0)
|
|
|
|
# Create 2 tasks to test order of printing exception
|
|
asyncio.create_task(task(1))
|
|
asyncio.create_task(task(2))
|
|
print("sleep")
|
|
for _ in range(2):
|
|
await asyncio.sleep(0)
|
|
|
|
# Create a task, let it run, then await it (no exception should be printed)
|
|
t = asyncio.create_task(task(3))
|
|
await asyncio.sleep(0)
|
|
try:
|
|
await t
|
|
except ValueError as er:
|
|
print(repr(er))
|
|
|
|
print("done")
|
|
|
|
|
|
asyncio.run(main())
|