Name

sigpending, rt_sigpending — examine pending signals

Synopsis

        #include <signal.h>
int sigpending( sigset_t *set);
 
[Note] Note
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
sigpending():
_POSIX_C_SOURCE

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 and −1 on error. In the event of an error, errno is set to indicate the cause.

ERRORS

EFAULT

set points to memory which is not a valid part of the process address space.

CONFORMING TO

POSIX.1-2001, POSIX.1-2008.

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.

SEE ALSO

kill(2), sigaction(2), signal(2), sigprocmask(2), sigsuspend(2), sigsetops(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/.


  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