pthread_kill - send a signal to a thread

       For an explanation of the terms used in this section, see attributes(7).
       ┌─────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                                                                   │ Attribute     │ Value   │
       ├─────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │ pthread_kill()                                                              │ Thread safety │ MT-Safe │
       └─────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

       The  pthread_kill()  function sends the signal sig to thread, a thread in the same process as the caller.
       The signal is asynchronously directed to thread.

       If sig is 0, then no signal is sent, but error checking is still performed.

EINVAL An invalid signal was specified.

       POSIX.1-2001.

       POSIX threads library (libpthread, -lpthread)

       pthread_kill - send a signal to a thread

       Signal  dispositions  are  process-wide: if a signal handler is installed, the handler will be invoked in
       the thread thread, but if the disposition of the signal  is  "stop",  "continue",  or  "terminate",  this
       action will affect the whole process.

       On success, pthread_kill() returns 0; on error, it returns an error number, and no signal is sent.

kill(2),   sigaction(2),   sigpending(2),  pthread_self(3),  pthread_sigmask(3),  raise(3),  pthreads(7),
       signal(7)

Linux man-pages 6.9.1                              2024-05-02                                    pthread_kill(3)

       POSIX.1-2008.

#include<signal.h>intpthread_kill(pthread_tthread,intsig);

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

       pthread_kill():
           _POSIX_C_SOURCE >= 199506L || _XOPEN_SOURCE >= 500

       The glibc implementation of pthread_kill() 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.

       POSIX.1-2008  recommends  that  if  an implementation detects the use of a thread ID after the end of its
       lifetime, pthread_kill() should return the error ESRCH.  The glibc implementation returns this  error  in
       the  cases  where an invalid thread ID can be detected.  But note also that POSIX says that an attempt to
       use a thread ID whose lifetime has ended produces undefined behavior, and an attempt to  use  an  invalid
       thread ID in a call to pthread_kill() can, for example, cause a segmentation fault.