Python 3.5+Async programmingfunction

asyncio.run_coroutine_threadsafe()

threads interop

Submits a coroutine to an event loop running in another thread and returns a concurrent.futures.Future to wait for the result.

Syntax

future = asyncio.run_coroutine_threadsafe(coro, loop)

This is the bridge from a plain thread into the loop: a worker thread may not call create_task, but this function is thread-safe. It returns a concurrent.futures Future, waited on with fut.result(timeout), which blocks. Calling result() on the loop's own thread hangs the program: the loop waits for itself. The loop is passed explicitly, because a foreign thread has no current loop.

Examples

import asyncio
async def add(a, b):
    await asyncio.sleep(0.01)
    return a + b
def worker(loop):
    fut = asyncio.run_coroutine_threadsafe(add(2, 3), loop)
    return fut.result(timeout=1)  # блокирует рабочий поток, а не цикл
async def main():
    loop = asyncio.get_running_loop()
    print(await asyncio.to_thread(worker, loop))  # → 5
asyncio.run(main())

See also

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