/* Copyright (C) 2002-2012 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <errno.h>
#include <signal.h>
#include <pthreadP.h>
#include <tls.h>
#include <sysdep.h>
#include <kernel-features.h>


int
__pthread_kill (pthread_t threadid, int signo)
{
  struct pthread *pd = (struct pthread *) threadid;

  /* Make sure the descriptor is valid.  */
  if (DEBUGGING_P && INVALID_TD_P (pd))
    /* Not a valid thread handle.  */
    return ESRCH;

  /* Force load of pd->tid into local variable or register.  Otherwise
     if a thread exits between ESRCH test and tgkill, we might return
     EINVAL, because pd->tid would be cleared by the kernel.  */
  pid_t tid = atomic_forced_read (pd->tid);
  if (__builtin_expect (tid <= KTID_TERMINATED, 0))
    /* Not a valid thread handle.  */
    return ESRCH;

  /* Disallow sending the signal we use for cancellation, timers,
     for the setxid implementation.  */
  if (signo == SIGCANCEL || signo == SIGTIMER || signo == SIGSETXID)
    return EINVAL;
    
  /* We have a special syscall to do the work.  */

  /* the KTID field in the TCB can be wrong under FreeBSD
     a) before __pthread_initialize_minimal is finished (with libpthread)
     b) in child just after fork
     c) in single threaded program (no libpthread at all) 

     In these situations no other thread can exist.
   */
  return INLINE_SYSCALL(thr_kill, 2, tid, signo);
}
strong_alias (__pthread_kill, pthread_kill)
