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| -rw-r--r-- | Doc/library/asyncio-eventloop.rst | 42 |
1 files changed, 24 insertions, 18 deletions
diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst index db63a5d..f86e784 100644 --- a/Doc/library/asyncio-eventloop.rst +++ b/Doc/library/asyncio-eventloop.rst @@ -186,19 +186,24 @@ Running and stopping the loop .. coroutinemethod:: loop.shutdown_default_executor(timeout=None) Schedule the closure of the default executor and wait for it to join all of - the threads in the :class:`ThreadPoolExecutor`. After calling this method, a - :exc:`RuntimeError` will be raised if :meth:`loop.run_in_executor` is called - while using the default executor. + the threads in the :class:`~concurrent.futures.ThreadPoolExecutor`. + Once this method has been called, + using the default executor with :meth:`loop.run_in_executor` + will raise a :exc:`RuntimeError`. - The *timeout* parameter specifies the amount of time the executor will - be given to finish joining. The default value is ``None``, which means the - executor will be given an unlimited amount of time. + The *timeout* parameter specifies the amount of time + (in :class:`float` seconds) the executor will be given to finish joining. + With the default, ``None``, + the executor is allowed an unlimited amount of time. - If the timeout duration is reached, a warning is emitted and executor is - terminated without waiting for its threads to finish joining. + If the *timeout* is reached, a :exc:`RuntimeWarning` is emitted + and the default executor is terminated + without waiting for its threads to finish joining. - Note that there is no need to call this function when - :func:`asyncio.run` is used. + .. note:: + + Do not call this method when using :func:`asyncio.run`, + as the latter handles default executor shutdown automatically. .. versionadded:: 3.9 @@ -213,22 +218,23 @@ Scheduling callbacks Schedule the *callback* :term:`callback` to be called with *args* arguments at the next iteration of the event loop. + Return an instance of :class:`asyncio.Handle`, + which can be used later to cancel the callback. + Callbacks are called in the order in which they are registered. Each callback will be called exactly once. - An optional keyword-only *context* argument allows specifying a + The optional keyword-only *context* argument specifies a custom :class:`contextvars.Context` for the *callback* to run in. - The current context is used when no *context* is provided. - - An instance of :class:`asyncio.Handle` is returned, which can be - used later to cancel the callback. + Callbacks use the current context when no *context* is provided. - This method is not thread-safe. + Unlike :meth:`call_soon_threadsafe`, this method is not thread-safe. .. method:: loop.call_soon_threadsafe(callback, *args, context=None) - A thread-safe variant of :meth:`call_soon`. Must be used to - schedule callbacks *from another thread*. + A thread-safe variant of :meth:`call_soon`. When scheduling callbacks from + another thread, this function *must* be used, since :meth:`call_soon` is not + thread-safe. Raises :exc:`RuntimeError` if called on a loop that's been closed. This can happen on a secondary thread when the main application is |