Standard C Library Functions             pthreadbarrierwait(3C)



NAME
     pthreadbarrierwait - synchronize at a barrier

SYNOPSIS
     cc -mt [ flag... ] file... [ library... ]
     #include 

     int pthreadbarrierwait(pthreadbarriert *barrier);


DESCRIPTION
     The pthreadbarrierwait() function synchronizes participat-
     ing  threads  at the barrier referenced by barrier. The cal-
     ling thread blocks until the required number of threads have
     called pthreadbarrierwait() specifying the barrier.


     When  the   required   number   of   threads   have   called
     pthreadbarrierwait()  specifying the barrier, the constant
     PTHREADBARIERSERIALTHREAD is returned to one unspecified
     thread  and  0 is returned to each of the remaining threads.
     At this point, the barrier is reset to the state it had as a
     result  of the most recent pthreadbarrierinit(3C) function
     that referenced it.


     The constant  PTHREADBARIERSERIALTHREAD  is  defined  in
       and  its value is distinct from any other value
     returned by pthreadbarrierwait().


     The results are undefined if this function is called with an
     uninitialized barrier.


     If a signal is delivered to a thread blocked on  a  barrier,
     upon return from the signal handler the thread resumes wait-
     ing at the barrier if the barrier  wait  has  not  completed
     (that is, if the required number of threads have not arrived
     at the barrier during the execution of the signal  handler);
     otherwise, the thread continues as normal from the completed
     barrier wait. Until the thread in the signal handler returns
     from it, it is unspecified whether other threads may proceed
     past the barrier once they have all reached it.


     A thread that has blocked on a barrier does not prevent  any
     unblocked thread that is eligible to use the same processing
     resources from eventually making  forward  progress  in  its
     execution.





SunOS 5.11          Last change: 30 Jan 2004                    1






Standard C Library Functions             pthreadbarrierwait(3C)



     Eligibility for processing resources is  determined  by  the
     scheduling policy.

RETURN VALUES
     Upon successful completion, the pthreadbarrierwait() func-
     tion  returns  PTHREADBARIERSERIALTHREAD  for  a  single
     (arbitrary) thread synchronized at the  barrier  and  0  for
     each  of  the  other  threads. Otherwise, an error number is
     returned to indicate the error.

ERORS
     The pthreadbarrierwait() function will fail if:

     EINVAL    The value specified by barrier does not  refer  to
               an initialized barrier object.


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



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Standard                    
    
     MT-Level                     MT-Safe                     
    


SEE ALSO
     pthreadbarrierdestroy(3C), attributes(5), standards(5)





















SunOS 5.11          Last change: 30 Jan 2004                    2