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timer_create(3)
NAME
  timer_create - Allocate a per-process timer

SYNOPSIS
  #include <signal.h>
  #include <time.h>

  int timer_create (
	  clockid_t clock_id,
	  struct sigevent *evp,
	  timer_t *timerid );

PARAMETERS
  clock_id
	The type of clock on which the timer is based. The CLOCK_REALTIME
	clock is supported.

  *evp	A pointer to a sigevent structure, which defines the signal sent to
	the process on timer expiration.

  *timerid
	A pointer to the timer ID returned by the call to the timer_create
	function.

DESCRIPTION
  The timer_create function allocates a per-process timer using the specified
  clock as the timing base. The timer_create function returns timer_id, which
  is used to identify the timer in timer requests. The timer ID is unique
  within the calling process until the timer is deleted. The timer is unarmed
  when first returned from a call to timer_create. To arm the timer, use the
  timer_settime function.

  The evp argument, if non-NULL, points to a sigevent structure, which
  defines the asynchronous notification that will occur when the timer
  expires.  If the sigev_notify member of evp is SIGEV_SIGNAL, the structure
  must contain the signal number and data value to send to the process when
  the timer expires. If the sigev_notify member is SIGEV_NONE, no
  notification will be sent.

  SIGALRM is the default signal for CLOCK_REALTIME if the evp argument is
  NULL.

  The maximum number of timers supported per process (TIMER_MAX) is defined
  in the <sys/rt_limits.h> header file, which is indirectly included through
  <time.h>.

  Timers are not inherited across fork calls. An exec call will disarm and
  delete a timer.

RETURN VALUES
  Upon successful completion, a value of 0 is returned.	 The timer_create
  function also returns, in timerid, a pointer to the timer ID that has been
  created.

  An unsuccessful call returns -1, and errno is set to indicate the error
  type.

ERRORS
  The timer_create function fails under the following conditions:

  [EAGAIN]	 The system lacks sufficient signal queuing resources to
		 honor the request.

		 The calling process has already created all of the timers it
		 is allowed.

  [EINVAL]	 The specified clock ID is not defined.

RELATED INFORMATION
  Functions: clock_getres(3), clock_gettime(3), clock_settime(3),
  timer_delete(3), timer_gettime(3), timer_settime(3)