.\" $NetBSD: sigsuspend.2,v 1.4 1995/02/27 12:37:46 cgd Exp $ .\" .\" Copyright (c) 1983, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)sigsuspend.2 8.1 (Berkeley) 6/4/93 .\" .Dd June 4, 1993 .Dt SIGSUSPEND 2 .Os .Sh NAME .Nm sigsuspend .Nd atomically release blocked signals and wait for interrupt .Sh SYNOPSIS .Fd #include <signal.h> .Ft int .Fo sigsuspend .Fa "const sigset_t *sigmask" .Fc .Sh DESCRIPTION .Fn Sigsuspend temporarily changes the blocked signal mask to the set to which .Fa 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. .Pp In normal usage, a signal is blocked using .Xr 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 .Fn sigsuspend with the previous mask returned by .Xr sigprocmask . .Sh RETURN VALUES The .Fn sigsuspend function always terminates by being interrupted, returning -1 with .Va errno set to .Dv EINTR . .Sh SEE ALSO .Xr sigaction 2 , .Xr sigprocmask 2 , .Xr sigsetops 3 .Sh STANDARDS The .Nm sigsuspend function call conforms to .St -p1003.1-88 .