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.

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

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.

rt_tgsigqueueinfo(2), sigaction(2), pthread_sigmask(3), sigqueue(3), sigwait(3), pthreads(7), signal(7)
2017-09-15 Linux