Submits an application-defined function for asynchronous execution on a dispatch queue and returns immediately.
SDKs
- iOS 4.0+
- macOS 10.6+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
Framework
- Dispatch
Declaration
void dispatch_async_f(dispatch _queue _t queue, void *context, dispatch _function _t work);
Parameters
queue
The queue on which to submit the function. The queue is retained by the system until the function has run to completion. This parameter cannot be
NULL
.context
The application-defined context parameter to pass to the function.
work
The application-defined function to invoke on the target queue. The first parameter passed to this function is the value of the
context
parameter. This parameter cannot beNULL
.
Discussion
This function is the fundamental mechanism for submitting application-defined functions to a dispatch queue. Calls to this function always return immediately after the function has been submitted and never wait for it to be invoked. The target queue determines whether the function is invoked serially or concurrently with respect to other tasks submitted to that same queue. Serial queues are processed concurrently with respect to each other.