Manual Pages for UNIX Operating System command usage for man sem_timedwait

Standard C Library Functions                    sem_timedwait(3C)



NAME
     sem_timedwait, sem_reltimedwait_np - lock a semaphore

SYNOPSIS
     #include 
     #include 

     int sem_timedwait(sem_t *restrict sem,
          const struct timespec *restrict abs_timeout);


     int sem_reltimedwait_np(sem_t *restrict sem,
          const struct timespec *restrict rel_timeout);


DESCRIPTION
     The sem_timedwait() function locks the semaphore  referenced
     by  sem  as  in  the  sem_wait(3C) function. However, if the
     semaphore cannot be locked without waiting for another  pro-
     cess  or  thread  to  unlock  the  semaphore by performing a
     sem_post(3C) function, this  wait  is  terminated  when  the
     specified timeout expires.


     The  sem_reltimedwait_np()  function  is  identical  to  the
     sem_timedwait()  function, except that the timeout is speci-
     fied as a relative time interval.


     For sem_timedwait(), the timeout expires when  the  absolute
     time  specified  by  abs_timeout  passes, as measured by the
     CLOCK_REALTIME clock (that is, when the value of that  clock
     equals  or  exceeds  abs_timeout),  or  if the absolute time
     specified by abs_timeout has already been passed at the time
     of the call.


     For sem_reltimedwait_np(), the timeout expires when the time
     interval specified by rel_timeout passes, as measured by the
     CLOCK_REALTIME clock, or if the time interval  specified  by
     rel_timeout is negative at the time of the call.


     The resolution of the  timeout  is  the  resolution  of  the
     CLOCK_REALTIME clock. The timespec data type is defined as a
     structure in the  header.


     Under no circumstance does the function fail with a  timeout
     if  the semaphore can be locked immediately. The validity of
     the abs_timeout need not be checked if the semaphore can  be
     locked immediately.



SunOS 5.11           Last change: 5 Feb 2008                    1






Standard C Library Functions                    sem_timedwait(3C)



RETURN VALUES
     The  sem_timedwait()  and  sem_reltimedwait_np()   functions
     return  0  if the calling process successfully performed the
     semaphore lock operation on the semaphore designated by sem.
     If  the call was unsuccessful, the state of the semaphore is
     be unchanged and the function returns -1 and sets  errno  to
     indicate the error.

ERRORS
     The sem_timedwait() and sem_reltimedwait_np() functions will
     fail if:

     EINVAL       The sem argument does  not  refer  to  a  valid
                  semaphore.


     EINVAL       The process or thread would have  blocked,  and
                  the  timeout  parameter specified a nanoseconds
                  field value less than zero or greater  than  or
                  equal to 1,000 million.


     ETIMEDOUT    The semaphore could not be  locked  before  the
                  specified timeout expired.



     The sem_timedwait() and sem_reltimedwait_np() functions  may
     fail if:

     EDEADLK    A deadlock condition was detected.


     EINTR      A signal interrupted this function.


ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:
















SunOS 5.11           Last change: 5 Feb 2008                    2






Standard C Library Functions                    sem_timedwait(3C)



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Commmitted                  |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe                     |
    |_____________________________|_____________________________|
    | Committed                   | See below.                  |
    |_____________________________|_____________________________|
    | Standard                    | See standards(5).           |
    |_____________________________|_____________________________|



     For sem_timedwait(), see standards(5).

SEE ALSO
     semctl(2),  semget(2),  semop(2),   time(2),   sem_post(3C),
     sem_trywait(3C)sem_wait(3C), attributes(5), standards(5)




































SunOS 5.11           Last change: 5 Feb 2008                    3