.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved 
.TH "SIGSUSPEND" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\" sigsuspend 
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.SH NAME
sigsuspend \- wait for a signal
.SH SYNOPSIS
.LP
\fB#include <signal.h>
.br
.sp
int sigsuspend(const sigset_t *\fP\fIsigmask\fP\fB); \fP
\fB
.br
\fP
.SH DESCRIPTION
.LP
The \fIsigsuspend\fP() function shall replace the current signal mask
of the calling thread with the set of signals pointed to
by \fIsigmask\fP and then suspend the thread until delivery of a signal
whose action is either to execute a signal-catching
function or to terminate the process. This shall not cause any other
signals that may have been pending on the process to become
pending on the thread.
.LP
If the action is to terminate the process then \fIsigsuspend\fP()
shall never return. If the action is to execute a
signal-catching function, then \fIsigsuspend\fP() shall return after
the signal-catching function returns, with the signal mask
restored to the set that existed prior to the \fIsigsuspend\fP() call.
.LP
It is not possible to block signals that cannot be ignored. This is
enforced by the system without causing an error to be
indicated.
.SH RETURN VALUE
.LP
Since \fIsigsuspend\fP() suspends thread execution indefinitely, there
is no successful completion return value. If a return
occurs, -1 shall be returned and \fIerrno\fP set to indicate the error.
.SH ERRORS
.LP
The \fIsigsuspend\fP() function shall fail if:
.TP 7
.B EINTR
A signal is caught by the calling process and control is returned
from the signal-catching function.
.sp
.LP
\fIThe following sections are informative.\fP
.SH EXAMPLES
.LP
None.
.SH APPLICATION USAGE
.LP
Normally, at the beginning of a critical code section, a specified
set of signals is blocked using the \fIsigprocmask\fP() function.
When the thread has completed the critical section and needs to
wait for the previously blocked signal(s), it pauses by calling \fIsigsuspend\fP()
with the mask that was returned by the \fIsigprocmask\fP() call.
.SH RATIONALE
.LP
None.
.SH FUTURE DIRECTIONS
.LP
None.
.SH SEE ALSO
.LP
\fISignal Concepts\fP, \fIpause\fP(), \fIsigaction\fP(), \fIsigaddset\fP(),
\fIsigdelset\fP(), \fIsigemptyset\fP(), \fIsigfillset\fP(), the
Base Definitions volume of IEEE\ Std\ 1003.1-2001, \fI<signal.h>\fP
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .