pthread_sigqueue — queue a signal and data to a thread


#include <signal.h>
#include <pthread.h>

int pthread_sigqueue(pthread_t thread, int sig,
                     const union sigval value);

Compile and link with -pthread.

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

pthread_sigqueue(): _GNU_SOURCE


The pthread_sigqueue() function performs a similar task to sigqueue(3), but, rather than sending a signal to a process, it sends a signal to a thread in the same process as the calling thread.

The thread argument is the ID of a thread in the same process as the caller. The sig argument specifies the signal to be sent. The value argument specifies data to accompany the signal; see sigqueue(3) for details.

Return Value

On success, pthread_sigqueue() returns 0; on error, it returns an error number.



The limit of signals which may be queued has been reached. (See signal(7) for further information.)


sig was invalid.


pthread_sigqueue() is not supported on this system.


thread is not valid.


The pthread_sigqueue() function first appeared in glibc 2.11.


For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
pthread_sigqueue() Thread safety MT-Safe

Conforming to

This function is a GNU extension.


The glibc implementation of pthread_sigqueue() gives an error (EINVAL) on attempts to send either of the real-time signals used internally by the NPTL threading implementation. See nptl(7) for details.

See Also

rt_tgsigqueueinfo(2), sigaction(2), pthread_sigmask(3), sigqueue(3), sigwait(3), pthreads(7), signal(7)


This page is part of release 5.04 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

Referenced By

clone(2), nptl(7), pthreads(7), rt_sigqueueinfo(2), signal(7), sigqueue(3).

2017-09-15 Linux Programmer's Manual