sysdeps/unix/sysv/linux/pthread_getcpuclockid.c

   1 /* pthread_getcpuclockid -- Get POSIX clockid_t for a pthread_t.  Linux version
   2    Copyright (C) 2000-2019 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If
  17    not, see <https://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <pthreadP.h>
  21 #include <sys/time.h>
  22 #include <tls.h>
  23 #include <kernel-posix-cpu-timers.h>
  24
  25
  26 int
  27 pthread_getcpuclockid (pthread_t threadid, clockid_t *clockid)
  28 {
  29   struct pthread *pd = (struct pthread *) threadid;
  30
  31   /* Make sure the descriptor is valid.  */
  32   if (INVALID_TD_P (pd))
  33     /* Not a valid thread handle.  */
  34     return ESRCH;
  35
  36   /* The clockid_t value is a simple computation from the TID.  */
  37
  38   const clockid_t tidclock = MAKE_THREAD_CPUCLOCK (pd->tid, CPUCLOCK_SCHED);
  39
  40   *clockid = tidclock;
  41   return 0;
  42 }