nptl/pthread_attr_init.c

   1 /* Copyright (C) 2002-2023 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 <string.h>
  20 #include <unistd.h>
  21 #include "pthreadP.h"
  22
  23 #include <shlib-compat.h>
  24
  25
  26 struct pthread_attr *__attr_list;
  27 int __attr_list_lock = LLL_LOCK_INITIALIZER;
  28
  29
  30 int
  31 __pthread_attr_init (pthread_attr_t *attr)
  32 {
  33   struct pthread_attr *iattr;
  34
  35   ASSERT_TYPE_SIZE (pthread_attr_t, __SIZEOF_PTHREAD_ATTR_T);
  36   ASSERT_PTHREAD_INTERNAL_SIZE (pthread_attr_t, struct pthread_attr);
  37
  38   /* Many elements are initialized to zero so let us do it all at
  39      once.  This also takes care of clearing the bytes which are not
  40      internally used.  */
  41   memset (attr, '\0', __SIZEOF_PTHREAD_ATTR_T);
  42
  43   iattr = (struct pthread_attr *) attr;
  44
  45   /* Default guard size specified by the standard.  */
  46   iattr->guardsize = __getpagesize ();
  47
  48   return 0;
  49 }
  50 libc_hidden_def (__pthread_attr_init)
  51 versioned_symbol (libc, __pthread_attr_init, pthread_attr_init, GLIBC_2_1);
  52
  53
  54 #if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_1)
  55 int
  56 __pthread_attr_init_2_0 (pthread_attr_t *attr)
  57 {
  58   /* This code is specific to the old LinuxThread code which has a too
  59      small pthread_attr_t definition.  The struct looked like
  60      this:  */
  61   struct old_attr
  62   {
  63     int detachstate;
  64     int schedpolicy;
  65     struct sched_param schedparam;
  66     int inheritsched;
  67     int scope;
  68   };
  69   struct pthread_attr *iattr;
  70
  71   /* Many elements are initialized to zero so let us do it all at
  72      once.  This also takes care of clearing the bytes which are not
  73      internally used.  */
  74   memset (attr, '\0', sizeof (struct old_attr));
  75
  76   iattr = (struct pthread_attr *) attr;
  77   iattr->flags |= ATTR_FLAG_OLDATTR;
  78
  79   /* We cannot enqueue the attribute because that member is not in the
  80      old attribute structure.  */
  81   return 0;
  82 }
  83 compat_symbol (libc, __pthread_attr_init_2_0, pthread_attr_init, GLIBC_2_0);
  84 #endif