Name
sigsuspend, rt_sigsuspend — wait for a signal
Synopsis
#include <signal.h>
int
sigsuspend( |
const sigset_t *mask); |
![[Note]](../stylesheet/note.png) |
Note | ||
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DESCRIPTION
sigsuspend() temporarily
replaces the signal mask of the calling process with the mask
given by mask and
then suspends the process until delivery of a signal whose
action is to invoke a signal handler or to terminate a
process.
If the signal terminates the process, then sigsuspend() does not return. If the signal
is caught, then sigsuspend()
returns after the signal handler returns, and the signal mask
is restored to the state before the call to sigsuspend().
It is not possible to block SIGKILL or SIGSTOP; specifying these signals in
mask, has no effect
on the process's signal mask.
RETURN VALUE
sigsuspend() always returns
−1, with errno set to
indicate the error (normally, EINTR).
ERRORS
- EFAULT
-
maskpoints to memory which is not a valid part of the process address space. - EINTR
-
The call was interrupted by a signal; signal(7).
NOTES
Normally, sigsuspend() is
used in conjunction with sigprocmask(2) in order to
prevent delivery of a signal during the execution of a
critical code section. The caller first blocks the signals
with sigprocmask(2). When the
critical code has completed, the caller then waits for the
signals by calling sigsuspend()
with the signal mask that was returned by sigprocmask(2) (in the
oldset
argument).
See sigsetops(3) for details on manipulating signal sets.
C library/kernel differences
The original Linux system call was named sigsuspend(). However, with the addition
of real-time signals in Linux 2.2, the fixed-size, 32-bit
sigset_t type supported by that
system call was no longer fit for purpose. Consequently, a
new system call, rt_sigsuspend(), was added to support an
enlarged sigset_t type. The new
system call takes a second argument, size_t sigsetsize, which
specifies the size in bytes of the signal set in mask. This argument is
currently required to have the value sizeof(sigset_t) (or the
error EINVAL results). The
glibc sigsuspend() wrapper
function hides these details from us, transparently calling
rt_sigsuspend() when the
kernel provides it.
SEE ALSO
kill(2), pause(2), sigaction(2), signal(2), sigprocmask(2), sigwaitinfo(2), sigsetops(3), sigwait(3), signal(7)
COLOPHON
This page is part of release 4.07 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
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Copyright (c) 2005 Michael Kerrisk based on earlier work by faithcs.unc.edu and Mike Battersby <mibdeakin.edu.au> %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END 2005-09-15, mtk, Created new page by splitting off from sigaction.2 |