Name
sigpending, rt_sigpending — examine pending signals
Synopsis
#include <signal.h>
int
sigpending( |
sigset_t *set); |
![[Note]](../stylesheet/note.png) |
Note | ||
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DESCRIPTION
sigpending() returns the set
of signals that are pending for delivery to the calling
thread (i.e., the signals which have been raised while
blocked). The mask of pending signals is returned in
set.
RETURN VALUE
sigpending() returns 0 on
success. On failure, −1 is returned and errno is set to indicate the error.
NOTES
See sigsetops(3) for details on manipulating signal sets.
If a signal is both blocked and has a disposition of
"ignored", it is not added to the mask of
pending signals when generated.
The set of signals that is pending for a thread is the union of the set of signals that is pending for that thread and the set of signals that is pending for the process as a whole; see signal(7).
A child created via fork(2) initially has an empty pending signal set; the pending signal set is preserved across an execve(2).
C library/kernel differences
The original Linux system call was named sigpending(). However, with the addition
of real-time signals in Linux 2.2, the fixed-size, 32-bit
sigset_t argument supported by
that system call was no longer fit for purpose.
Consequently, a new system call, rt_sigpending(), 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 set. The glibc sigpending() wrapper function hides these
details from us, transparently calling rt_sigpending() when the kernel provides
it.
BUGS
In versions of glibc up to and including 2.2.1, there is a
bug in the wrapper function for sigpending() which means that information
about pending real-time signals is not correctly
returned.
COLOPHON
This page is part of release 5.11 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 |