nptl/sysdeps/unix/sysv/linux/pthread_attr_setaffinity.c

   1 /* Copyright (C) 2003, 2004, 2006 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <assert.h>
  21 #include <errno.h>
  22 #include <limits.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <pthreadP.h>
  26 #include <shlib-compat.h>
  27
  28
  29 /* Defined in pthread_setaffinity.c.  */
  30 extern size_t __kernel_cpumask_size attribute_hidden;
  31 extern int __determine_cpumask_size (pid_t tid);
  32
  33
  34 int
  35 __pthread_attr_setaffinity_new (pthread_attr_t *attr, size_t cpusetsize,
  36                                 const cpu_set_t *cpuset)
  37 {
  38   struct pthread_attr *iattr;
  39
  40   assert (sizeof (*attr) >= sizeof (struct pthread_attr));
  41   iattr = (struct pthread_attr *) attr;
  42
  43   if (cpuset == NULL || cpusetsize == 0)
  44     {
  45       free (iattr->cpuset);
  46       iattr->cpuset = NULL;
  47       iattr->cpusetsize = 0;
  48     }
  49   else
  50     {
  51       if (__kernel_cpumask_size == 0)
  52         {
  53           int res = __determine_cpumask_size (THREAD_SELF->tid);
  54           if (res != 0)
  55             /* Some serious problem.  */
  56             return res;
  57         }
  58
  59       /* Check whether the new bitmask has any bit set beyond the
  60          last one the kernel accepts.  */
  61       for (size_t cnt = __kernel_cpumask_size; cnt < cpusetsize; ++cnt)
  62         if (((char *) cpuset)[cnt] != '\0')
  63           /* Found a nonzero byte.  This means the user request cannot be
  64              fulfilled.  */
  65           return EINVAL;
  66
  67       if (iattr->cpusetsize != cpusetsize)
  68         {
  69           void *newp = (cpu_set_t *) realloc (iattr->cpuset, cpusetsize);
  70           if (newp == NULL)
  71             return ENOMEM;
  72
  73           iattr->cpuset = newp;
  74           iattr->cpusetsize = cpusetsize;
  75         }
  76
  77       memcpy (iattr->cpuset, cpuset, cpusetsize);
  78     }
  79
  80   return 0;
  81 }
  82 versioned_symbol (libpthread, __pthread_attr_setaffinity_new,
  83                   pthread_attr_setaffinity_np, GLIBC_2_3_4);
  84
  85
  86 #if SHLIB_COMPAT (libpthread, GLIBC_2_3_3, GLIBC_2_3_4)
  87 int
  88 __pthread_attr_setaffinity_old (pthread_attr_t *attr, cpu_set_t *cpuset)
  89 {
  90   /* The old interface by default assumed a 1024 processor bitmap.  */
  91   return __pthread_attr_setaffinity_new (attr, 128, cpuset);
  92 }
  93 compat_symbol (libpthread, __pthread_attr_setaffinity_old,
  94                pthread_attr_setaffinity_np, GLIBC_2_3_3);
  95 #endif