rt/clock_getcpuclockid.c

   1 /* Get a clockid_t for the process CPU clock of a given process.  Generic.
   2    Copyright (C) 2000-2017 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
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <time.h>
  21 #include <unistd.h>
  22
  23 int
  24 __clock_getcpuclockid (pid_t pid, clockid_t *clock_id)
  25 {
  26   /* We don't allow any process ID but our own.  */
  27   if (pid != 0 && pid != getpid ())
  28     return EPERM;
  29
  30 #ifdef CLOCK_PROCESS_CPUTIME_ID
  31   /* Store the number.  */
  32   *clock_id = CLOCK_PROCESS_CPUTIME_ID;
  33
  34   return 0;
  35 #else
  36   /* We don't have a timer for that.  */
  37   return ENOENT;
  38 #endif
  39 }
  40 weak_alias (__clock_getcpuclockid, clock_getcpuclockid)