nptl/pthread_getaffinity.c

   1 /* Copyright (C) 2003-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
   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    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <limits.h>
  21 #include <pthreadP.h>
  22 #include <string.h>
  23 #include <sysdep.h>
  24 #include <sys/param.h>
  25 #include <sys/types.h>
  26 #include <shlib-compat.h>
  27
  28
  29 int
  30 __pthread_getaffinity_np (pthread_t th, size_t cpusetsize, cpu_set_t *cpuset)
  31 {
  32   const struct pthread *pd = (const struct pthread *) th;
  33
  34   int res = INTERNAL_SYSCALL_CALL (sched_getaffinity, pd->tid,
  35                                    MIN (INT_MAX, cpusetsize), cpuset);
  36   if (INTERNAL_SYSCALL_ERROR_P (res))
  37     return INTERNAL_SYSCALL_ERRNO (res);
  38
  39   /* Clean the rest of the memory the kernel didn't do.  */
  40   memset ((char *) cpuset + res, '\0', cpusetsize - res);
  41
  42   return 0;
  43 }
  44 libc_hidden_def (__pthread_getaffinity_np)
  45 versioned_symbol (libc, __pthread_getaffinity_np, pthread_getaffinity_np,
  46                   GLIBC_2_32);
  47
  48 #if SHLIB_COMPAT (libc, GLIBC_2_3_4, GLIBC_2_32)
  49 strong_alias (__pthread_getaffinity_np, __pthread_getaffinity_alias)
  50 compat_symbol (libc, __pthread_getaffinity_alias, pthread_getaffinity_np,
  51                GLIBC_2_3_4);
  52 #endif
  53
  54 #if SHLIB_COMPAT (libc, GLIBC_2_3_3, GLIBC_2_3_4)
  55 int
  56 __pthread_getaffinity_old (pthread_t th, cpu_set_t *cpuset)
  57 {
  58   /* The old interface by default assumed a 1024 processor bitmap.  */
  59   return __pthread_getaffinity_np (th, 128, cpuset);
  60 }
  61 compat_symbol (libc, __pthread_getaffinity_old, pthread_getaffinity_np,
  62                GLIBC_2_3_3);
  63 #endif