NAME

    sigwait - Causes a thread to wait for an asynchronous signal

 SYNOPSIS

     #include <pthread.h>

     int sigwait( sigset_t *set );

 PARAMETERS

     set                Set of asynchronous pending signals from which
                        this routine chooses one signal on which the
                        calling thread will wait.

 DESCRIPTION

 This routine causes a thread to wait for an asynchronous signal by
 choosing a pending signal from set, atomically clearing it from the
 system's set of pending signals and returning that signal number.  If no
 signal in set is pending at the time of the call, the thread is blocked
 until one or more signals becomes pending.  The signals defined by set
 may be unblocked during the call to this routine and will be blocked
 when the thread returns from the call unless some other thread is
 currently waiting for one of those signals.

 If more than one thread is using this routine to wait for the same
 signal, only one of these threads will return from this routine with the
 signal number.

 RETURN VALUES

 Possible return values are as follows:

    Return          Error      Description
    __________________________________________________
    Signal number              Successful completion.

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

 RELATED INFORMATION

     FUNCTIONS: pthread_cancel
                pthread_setasynccancel