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:c:type:`uv_async_t` --- Async handle

deps/uv/docs/src/async.rst

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.. _async:

:c:type:uv_async_t --- Async handle

Async handles allow the user to "wakeup" the event loop and get a callback called from another thread.

Data types

.. c:type:: uv_async_t

Async handle type.

.. c:type:: void (uv_async_cb)(uv_async_t handle)

Type definition for callback passed to :c:func:`uv_async_init`.

Public members ^^^^^^^^^^^^^^

N/A

.. seealso:: The :c:type:uv_handle_t members also apply.

API

.. c:function:: int uv_async_init(uv_loop_t* loop, uv_async_t* async, uv_async_cb async_cb)

Initialize the handle. A NULL callback is allowed.

:returns: 0 on success, or an error code < 0 on failure.

.. note::
    Unlike other handle initialization  functions, it immediately starts the handle.

.. c:function:: int uv_async_send(uv_async_t* async)

Wake up the event loop and call the async handle's callback.

:returns: 0 on success, or an error code < 0 on failure.

.. note::
    It's safe to call this function from any thread. The callback will be called on the
    loop thread.

.. note::
    :c:func:`uv_async_send` is `async-signal-safe <https://man7.org/linux/man-pages/man7/signal-safety.7.html>`_.
    It's safe to call this function from a signal handler.

.. warning::
    libuv will coalesce calls to :c:func:`uv_async_send`, that is, not every call to it will
    yield an execution of the callback. For example: if :c:func:`uv_async_send` is called 5
    times in a row before the callback is called, the callback will only be called once. If
    :c:func:`uv_async_send` is called again after the callback was called, it will be called
    again.

.. seealso:: The :c:type:uv_handle_t API functions also apply.