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pthread_sigmask(3) [bsd man page]

PTHREAD_SIGMASK(3)					     Linux Programmer's Manual						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. Feature Test Macro Requirements for glibc (see feature_test_macros(7)): pthread_sigmask(): _POSIX_C_SOURCE >= 199506L || _XOPEN_SOURCE >= 500 DESCRIPTION
The pthread_sigmask() function is just like sigprocmask(2), with the difference that its use in multithreaded programs is explicitly speci- fied by POSIX.1. 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). ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7). +------------------+---------------+---------+ |Interface | Attribute | Value | +------------------+---------------+---------+ |pthread_sigmask() | Thread safety | MT-Safe | +------------------+---------------+---------+ CONFORMING TO
POSIX.1-2001, POSIX.1-2008. NOTES
A new thread inherits a copy of its creator's signal mask. The glibc pthread_sigmask() function silently ignores attempts to block the two real-time signals that are used internally by the NPTL threading implementation. See nptl(7) for details. 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 = arg; int s, sig; for (;;) { s = sigwait(set, &sig); if (s != 0) handle_error_en(s, "sigwait"); printf("Signal handling thread got signal %d ", sig); } } int main(int argc, char *argv[]) { pthread_t thread; sigset_t set; int s; /* Block SIGQUIT and SIGUSR1; 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 4.15 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 2017-09-15 PTHREAD_SIGMASK(3)

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