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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | NOTES | BUGS | SEE ALSO | COLOPHON |
SIGPENDING(2) Linux Programmer's Manual SIGPENDING(2)
sigpending, rt_sigpending - examine pending signals
#include <signal.h>
int sigpending(sigset_t *set);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
sigpending(): _POSIX_C_SOURCE
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.
sigpending() returns 0 on success and -1 on error. In the event of
an error, errno is set to indicate the cause.
EFAULT set points to memory which is not a valid part of the process
address space.
POSIX.1-2001, POSIX.1-2008.
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.
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.
kill(2), sigaction(2), signal(2), sigprocmask(2), sigsuspend(2),
sigsetops(3), signal(7)
This page is part of release 4.12 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/.
Linux 2016-03-15 SIGPENDING(2)
Pages that refer to this page: clone(2), fork(2), sigaction(2), signal(2), sigprocmask(2), sigwaitinfo(2), syscalls(2), pthread_create(3), pthread_kill(3), pthread_sigmask(3), sigsetops(3), sigwait(3), signal(7), signal-safety(7)