nptl/pthread_getaffinity.c

   1 /* Copyright (C) 2003-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <limits.h>
  20 #include <pthreadP.h>
  21 #include <string.h>
  22 #include <sysdep.h>
  23 #include <sys/param.h>
  24 #include <sys/types.h>
  25 #include <shlib-compat.h>
  26
  27
  28 int
  29 __pthread_getaffinity_np (pthread_t th, size_t cpusetsize, cpu_set_t *cpuset)
  30 {
  31   const struct pthread *pd = (const struct pthread *) th;
  32
  33   int res = INTERNAL_SYSCALL_CALL (sched_getaffinity, pd->tid,
  34                                    MIN (INT_MAX, cpusetsize), cpuset);
  35   if (INTERNAL_SYSCALL_ERROR_P (res))
  36     return INTERNAL_SYSCALL_ERRNO (res);
  37
  38   /* Clean the rest of the memory the kernel didn't do.  */
  39   memset ((char *) cpuset + res, '\0', cpusetsize - res);
  40
  41   return 0;
  42 }
  43 libc_hidden_def (__pthread_getaffinity_np)
  44 versioned_symbol (libc, __pthread_getaffinity_np, pthread_getaffinity_np,
  45                   GLIBC_2_32);
  46
  47 #if SHLIB_COMPAT (libc, GLIBC_2_3_4, GLIBC_2_32)
  48 strong_alias (__pthread_getaffinity_np, __pthread_getaffinity_alias)
  49 compat_symbol (libc, __pthread_getaffinity_alias, pthread_getaffinity_np,
  50                GLIBC_2_3_4);
  51 #endif
  52
  53 #if SHLIB_COMPAT (libc, GLIBC_2_3_3, GLIBC_2_3_4)
  54 int
  55 __pthread_getaffinity_old (pthread_t th, cpu_set_t *cpuset)
  56 {
  57   /* The old interface by default assumed a 1024 processor bitmap.  */
  58   return __pthread_getaffinity_np (th, 128, cpuset);
  59 }
  60 compat_symbol (libc, __pthread_getaffinity_old, pthread_getaffinity_np,
  61                GLIBC_2_3_3);
  62 #endif