| dispatch_after(3) | Library Functions Manual | dispatch_after(3) |
dispatch_after —
schedule blocks for deferred execution
#include
<dispatch/dispatch.h>
void
dispatch_after(dispatch_time_t
when, dispatch_queue_t queue,
void (^block)(void));
void
dispatch_after_f(dispatch_time_t
when, dispatch_queue_t queue,
void *context, void (*function)(void
*));
The
dispatch_after()
function submits the block to the given
queue at the time specified by the
when parameter. The when
parameter is a value created by
dispatch_time()
or
dispatch_walltime().
Submission of the block may be delayed by the system in order to improve
power consumption and system performance. The system applies a leeway (see
dispatch_source_set_timer(3))
that is equal to one tenth of the interval between
when and the time at which the function is called,
with the leeway capped to at least one millisecond and at most one
minute.
For a more detailed description about submitting blocks to queues, see dispatch_async(3).
The
dispatch_after()
function is a wrapper around
dispatch_after_f().
dispatch_after() retains the passed
queue.
Specifying DISPATCH_TIME_NOW as the
when parameter is supported, but is not as efficient
as calling dispatch_async().
The result of passing DISPATCH_TIME_FOREVER as the when parameter is undefined.
| May 1, 2009 | Darwin |