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SIGSUSPEND(2) FreeBSD 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 IEEE Std
1003.1-1990 ("POSIX.1").
FreeBSD 14.0-RELEASE-p6 August 16, 2013 FreeBSD 14.0-RELEASE-p6