This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       The pthread_kill() function provides a mechanism for asynchronously directing a signal at a thread in the
       calling process. This could be used, for example, by one thread to affect broadcast delivery of a  signal
       to a set of threads.

       Note  that  pthread_kill()  only  causes the signal to be handled in the context of the given thread; the
       signal action (termination or stopping) affects the process as a whole.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for  Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical  and  Electronics
       Engineers, Inc and The Open Group.  In the event of any discrepancy between this version and the original
       IEEE  and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document.
       The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                  PTHREAD_KILL(3POSIX)

       The pthread_kill() function shall request that a signal be delivered to the specified thread.

       As in kill(), if sig is zero, error checking shall be performed but no signal shall actually be sent.

       The pthread_kill() function shall fail if:

       EINVAL The value of the sig argument is an invalid or unsupported signal number.

       The pthread_kill() function shall not return an error code of [EINTR].

       Thefollowingsectionsareinformative.

       None.

       A  future  version  of this standard may require that pthread_kill() not fail with [ESRCH] in the case of
       sending signals to an inactive thread (a terminated thread not yet detached or joined),  even  though  no
       signal will be delivered because the thread is no longer running.

       pthread_kill — send a signal to a thread

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult the corresponding Linux manual page for details of Linux behavior), or the  interface
       may not be implemented on Linux.

       If an implementation detects use of a thread ID after the end of its lifetime, it is recommended that the
       function should fail and report an [ESRCH] error.

       Existing implementations vary on the result of a pthread_kill() with a thread ID indicating  an  inactive
       thread  (a terminated thread that has not been detached or joined). Some indicate success on such a call,
       while others give an error of [ESRCH].  Since the  definition  of  thread  lifetime  in  this  volume  of
       POSIX.1‐2017  covers  inactive  threads, the [ESRCH] error as described is inappropriate in this case. In
       particular, this means that an application cannot have one thread check for termination of  another  with
       pthread_kill().

       Upon  successful  completion,  the  function shall return a value of zero.  Otherwise, the function shall
       return an error number. If the pthread_kill() function fails, no signal shall be sent.

kill(), pthread_self(), raise()

       The Base Definitions volume of POSIX.1‐2017, <signal.h>

       #include <signal.h>

       int pthread_kill(pthread_t thread, int sig);