Manual Pages for UNIX Operating System command usage for man pthread_cond_signal

Standard C Library Functions              pthread_cond_signal(3C)



NAME
     pthread_cond_signal,  pthread_cond_broadcast  -  signal   or
     broadcast a condition

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

     int pthread_cond_signal(pthread_cond_t *cond);


     int pthread_cond_broadcast(pthread_cond_t *cond);


DESCRIPTION
     These two functions are used to unblock threads blocked on a
     condition variable.


     The pthread_cond_signal() call unblocks at least one of  the
     threads that are blocked on the specified condition variable
     cond (if any threads are blocked on cond).


     The  pthread_cond_broadcast()  call  unblocks  all   threads
     currently blocked on the specified condition variable cond.


     If more than one thread is blocked on a condition  variable,
     the  scheduling policy determines the order in which threads
     are unblocked. When each thread unblocked as a result  of  a
     pthread_cond_signal()  or  pthread_cond_broadcast()  returns
     from     its     call     to     pthread_cond_wait()      or
     pthread_cond_timedwait(),  the  thread  owns  the mutex with
     which      it      called       pthread_cond_wait()       or
     pthread_cond_timedwait().  The  thread(s) that are unblocked
     contend for the mutex according to the scheduling policy (if
     applicable), and as if each had called pthread_mutex_lock().


     The pthread_cond_signal() or pthread_cond_broadcast()  func-
     tions  may be called by a thread whether or not it currently
     owns the mutex that threads calling  pthread_cond_wait()  or
     pthread_cond_timedwait()  have associated with the condition
     variable  during  their  waits;  however,   if   predictable
     scheduling  behavior  is required, then that mutex is locked
     by   the    thread    calling    pthread_cond_signal()    or
     pthread_cond_broadcast().


     The pthread_cond_signal() and pthread_cond_broadcast() func-
     tions  have  no  effect  if  there  are no threads currently



SunOS 5.11          Last change: 23 Mar 2005                    1






Standard C Library Functions              pthread_cond_signal(3C)



     blocked on cond.

RETURN VALUES
     If     successful,     the     pthread_cond_signal()     and
     pthread_cond_broadcast()  functions return  0. Otherwise, an
     error number is returned to indicate the error.

ERRORS
     The   pthread_cond_signal()   and   pthread_cond_broadcast()
     function may fail if:

     EINVAL    The value cond does not refer  to  an  initialized
               condition variable.


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



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


SEE ALSO
     pthread_cond_init(3C),                pthread_cond_wait(3C),
     pthread_cond_timedwait(3C),   attributes(5),   condition(5),
     standards(5)



















SunOS 5.11          Last change: 23 Mar 2005                    2