man/dispatch_after.3

   1 .\" Copyright (c) 2008-2010 Apple Inc. All rights reserved.
   2 .Dd May 1, 2009
   3 .Dt dispatch_after 3
   4 .Os Darwin
   5 .Sh NAME
   6 .Nm dispatch_after
   7 .Nd schedule blocks for deferred execution
   8 .Sh SYNOPSIS
   9 .Fd #include <dispatch/dispatch.h>
  10 .Ft void
  11 .Fo dispatch_after
  12 .Fa "dispatch_time_t when" "dispatch_queue_t queue" "void (^block)(void)"
  13 .Fc
  14 .Ft void
  15 .Fo dispatch_after_f
  16 .Fa "dispatch_time_t when" "dispatch_queue_t queue" "void *context" "void (*function)(void *)"
  17 .Fc
  18 .Sh DESCRIPTION
  19 The
  20 .Fn dispatch_after
  21 function submits the
  22 .Fa block
  23 to the given
  24 .Fa queue
  25 at the time specified by the
  26 .Fa when
  27 parameter.
  28 The
  29 .Fa when
  30 parameter is a value created by
  31 .Fn dispatch_time
  32 or
  33 .Fn dispatch_walltime .
  34 .Pp
  35 For a more detailed description about submitting blocks to queues, see
  36 .Xr dispatch_async 3 .
  37 .Sh CAVEATS
  38 .Fn dispatch_after
  39 retains the passed queue.
  40 .Pp
  41 Specifying
  42 .Vt DISPATCH_TIME_NOW
  43 as the
  44 .Fa when
  45 parameter
  46 is supported, but is not as efficient as calling
  47 .Fn dispatch_async .
  48 .Pp
  49 The result of passing
  50 .Vt DISPATCH_TIME_FOREVER
  51 as the
  52 .Fa when
  53 parameter is undefined.
  54 .Pp
  55 .Sh FUNDAMENTALS
  56 The
  57 .Fn dispatch_after
  58 function is a wrapper around
  59 .Fn dispatch_after_f .
  60 .Sh SEE ALSO
  61 .Xr dispatch 3 ,
  62 .Xr dispatch_async 3 ,
  63 .Xr dispatch_time 3