freebsd man page for sigsuspend

SIGSUSPEND(2)						      BSD System Calls Manual						     SIGSUSPEND(2)

NAME
     sigsuspend -- atomically release blocked signals and wait for interrupt

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <signal.h>

     int
     sigsuspend(const sigset_t *sigmask);

DESCRIPTION
     The sigsuspend() system call 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
     returned by sigprocmask(2).

RETURN VALUES
     The sigsuspend() system call always terminates by being interrupted, returning -1 with errno set to EINTR.

SEE ALSO
     pselect(2), sigaction(2), sigpending(2), sigprocmask(2), sigtimedwait(2), sigwait(2), sigwaitinfo(2), sigsetops(3)

STANDARDS
     The sigsuspend() system call is expected to conform to ISO/IEC 9945-1:1990 (``POSIX.1'').

BSD
								  August 16, 2013							       BSD