NAME

    pthread_cond_signal - Wakes one thread that is waiting on a
                          condition variable

 SYNOPSIS

     #include <pthread.h>

     int pthread_cond_signal(pthread_cond_t *cond);

 PARAMETERS

     cond             Condition variable signaled.

 DESCRIPTION

 The pthread_cond_signal() routine wakes one thread waiting on a condi-
 tion variable. Calling this routine implies that data guarded by the
 associated mutex has changed so that it is possible for a single waiting
 thread to proceed. Call this routine when any thread waiting on the
 specified condition variable might find its predicate true, but only one
 thread needs to proceed.

 The scheduling policy determines which thread is awakened. For policies
 SCHED_FIFO and SCHED_RR a blocked thread is chosen in priority order.

 Call this routine when the associated mutex is either locked or
 unlocked.

 RETURN VALUES

 If the function fails, errno may be set to one of the following values:

    Return   Error      Description
    ___________________________________________________________
     0                  Successful completion.

    -1      [EINVAL]    The value specified by cond is invalid.

    RELATED INFORMATION

      FUNCTIONS:  pthread_cond_broadcast
                  pthread_cond_destroy
                  pthread_cond_init
                  pthread_cond_timedwait
                  pthread_cond_wait