pthread_sigmask(3)
NAME
pthread_sigmask - examine and change mask of blocked signals
SYNOPSIS
#include <signal.h> int pthread_sigmask(int how, const sigset_t *set, sigset_t *oldset); Compile and link with -pthread.
DESCRIPTION
The pthread_sigmask() function is just like sigprocmask(2), with the
difference that its use in multithreaded programs is explicitly specified by POSIX.1-2001. Other differences are noted in this page.
For a description of the arguments and operation of this function, see
sigprocmask(2).
RETURN VALUE
On success, pthread_sigmask() returns 0; on error, it returns an error
number.
ERRORS
See sigprocmask(2).
CONFORMING TO
POSIX.1-2001.
NOTES
A new thread inherits a copy of its creator's signal mask.
EXAMPLE
- The program below blocks some signals in the main thread, and then creates a dedicated thread to fetch those signals via sigwait(3). The
following shell session demonstrates its use:
- $ ./a.out &
[1] 5423
$ kill -QUIT %1
Signal handling thread got signal 3
$ kill -USR1 %1
Signal handling thread got signal 10
$ kill -TERM %1
[1]+ Terminated ./a.out - Program source
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>- /* Simple error handling functions */
- #define handle_error_en(en, msg) \
do { errno = en; perror(msg); exit(EXIT_FAILURE); } while (0)
- static void *
sig_thread(void *arg)
{ - sigset_t *set = (sigset_t *) arg;
int s, sig; - for (;;) {
s = sigwait(set, &sig);
if (s != 0)handle_error_en(s, "sigwait");printf("Signal handling thread got signal %d\n", sig); - }
- }
- int
main(int argc, char *argv[])
{ - pthread_t thread;
sigset_t set;
int s; - /* Block SIGINT; other threads created by main() will inherit
a copy of the signal mask. */
- sigemptyset(&set);
sigaddset(&set, SIGQUIT);
sigaddset(&set, SIGUSR1);
s = pthread_sigmask(SIG_BLOCK, &set, NULL);
if (s != 0)handle_error_en(s, "pthread_sigmask"); - s = pthread_create(&thread, NULL, &sig_thread, (void *) &set);
if (s != 0)handle_error_en(s, "pthread_create"); - /* Main thread carries on to create other threads and/or do
other work */
- pause(); /* Dummy pause so we can test program */
- }
SEE ALSO
sigaction(2), sigpending(2), sigprocmask(2) pthread_create(3), pthread_kill(3), sigsetops(3), pthreads(7), signal(7)
COLOPHON
- This page is part of release 3.25 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.