Wakes all threads that are waiting on the specified condition
    variable.

1  –  C Binding

    #include <pthread.h>

    int
    pthread_cond_broadcast (
             pthread_cond_t   *cond);

2  –  Arguments

 cond

    Condition variable upon which the threads (to be awakened) are
    waiting.

3  –  Description

    This routine unblocks all threads waiting on the specified
    condition variable cond. Calling this routine implies that data
    guarded by the associated mutex has changed, so that it might be
    possible for one or more waiting threads to proceed. The threads
    that are unblocked shall contend for the mutex according to their
    respective scheduling policies (if applicable).

    If only one of the threads waiting on a condition variable may be
    able to proceed, but one of those threads can proceed, then use
    pthread_cond_signal() instead.

    Whether the associated mutex is locked or unlocked, you can still
    call this routine. However, if predictable scheduling behavior is
    required, that mutex should then be locked by the thread calling
    the pthread_cond_broadcast() routine.

    If no threads are waiting on the specified condition variable,
    this routine takes no action. The broadcast does not propagate to
    the next condition variable wait.

4  –  Return Values

    If an error condition occurs, this routine returns an integer
    value indicating the type of error. Possible return values are as
    follows:

    Return      Description

    0           Successful completion.
    [EINVAL]    The value specified by cond is not a valid condition
                variable.

5  –  Associated Routines

       pthread_cond_destroy()
       pthread_cond_init()
       pthread_cond_signal()
       pthread_cond_timedwait()
       pthread_cond_wait()