SIGSUSPEND(2) BSD Programmer's Manual SIGSUSPEND(2)
sigsuspend - atomically release blocked signals and wait for interrupt
sigsuspend(const sigset_t *sigmask);
Sigsuspend() temporarily changes the blocked signal mask to the set to
which sigmask points, and then waits for a signal to arrive; on return
the previous set of masked signals is restored. The signal mask set is
usually empty to indicate that all signals are to be unblocked for the
duration of the call.
In normal usage, a signal is blocked using sigprocmask(2) to begin a
critical section, variables modified on the occurrence of the signal are
examined to determine that there is no work to be done, and the process
pauses awaiting work by using sigsuspend() with the previous mask re-
turned by sigprocmask.
The sigsuspend() function always terminates by being interrupted, return-
ing -1 with errno set to EINTR.
sigprocmask(2), sigaction(2), sigsetops(3)
The sigsupend function call conforms to IEEE Std1003.1-1988 (``POSIX'').
4.4BSD June 4, 1993 1