mirror of
https://github.com/python/cpython.git
synced 2025-11-04 07:31:38 +00:00
73 lines
2 KiB
Python
73 lines
2 KiB
Python
__all__ = 'run',
|
|
|
|
from . import coroutines
|
|
from . import events
|
|
from . import tasks
|
|
|
|
|
|
def run(main, *, debug=False):
|
|
"""Run a coroutine.
|
|
|
|
This function runs the passed coroutine, taking care of
|
|
managing the asyncio event loop and finalizing asynchronous
|
|
generators.
|
|
|
|
This function cannot be called when another asyncio event loop is
|
|
running in the same thread.
|
|
|
|
If debug is True, the event loop will be run in debug mode.
|
|
|
|
This function always creates a new event loop and closes it at the end.
|
|
It should be used as a main entry point for asyncio programs, and should
|
|
ideally only be called once.
|
|
|
|
Example:
|
|
|
|
async def main():
|
|
await asyncio.sleep(1)
|
|
print('hello')
|
|
|
|
asyncio.run(main())
|
|
"""
|
|
if events._get_running_loop() is not None:
|
|
raise RuntimeError(
|
|
"asyncio.run() cannot be called from a running event loop")
|
|
|
|
if not coroutines.iscoroutine(main):
|
|
raise ValueError("a coroutine was expected, got {!r}".format(main))
|
|
|
|
loop = events.new_event_loop()
|
|
try:
|
|
events.set_event_loop(loop)
|
|
loop.set_debug(debug)
|
|
return loop.run_until_complete(main)
|
|
finally:
|
|
try:
|
|
_cancel_all_tasks(loop)
|
|
loop.run_until_complete(loop.shutdown_asyncgens())
|
|
finally:
|
|
events.set_event_loop(None)
|
|
loop.close()
|
|
|
|
|
|
def _cancel_all_tasks(loop):
|
|
to_cancel = [task for task in tasks.all_tasks(loop)
|
|
if not task.done()]
|
|
if not to_cancel:
|
|
return
|
|
|
|
for task in to_cancel:
|
|
task.cancel()
|
|
|
|
loop.run_until_complete(
|
|
tasks.gather(*to_cancel, loop=loop, return_exceptions=True))
|
|
|
|
for task in to_cancel:
|
|
if task.cancelled():
|
|
continue
|
|
if task.exception() is not None:
|
|
loop.call_exception_handler({
|
|
'message': 'unhandled exception during asyncio.run() shutdown',
|
|
'exception': task.exception(),
|
|
'task': task,
|
|
})
|