nptl/pthread_mutex_init.c

   1 /* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   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 <string.h>
  22 #include "pthreadP.h"
  23
  24
  25 static const struct pthread_mutexattr default_attr =
  26   {
  27     /* Default is a normal mutex, not shared between processes.  */
  28     .mutexkind = PTHREAD_MUTEX_NORMAL
  29   };
  30
  31
  32 int
  33 __pthread_mutex_init (mutex, mutexattr)
  34      pthread_mutex_t *mutex;
  35      const pthread_mutexattr_t *mutexattr;
  36 {
  37   const struct pthread_mutexattr *imutexattr;
  38
  39   assert (sizeof (pthread_mutex_t) <= __SIZEOF_PTHREAD_MUTEX_T);
  40
  41   imutexattr = (const struct pthread_mutexattr *) mutexattr ?: &default_attr;
  42
  43   /* Clear the whole variable.  */
  44   memset (mutex, '\0', __SIZEOF_PTHREAD_MUTEX_T);
  45
  46   /* Copy the values from the attribute.  */
  47   mutex->__data.__kind = imutexattr->mutexkind & ~0x80000000;
  48
  49   /* Default values: mutex not used yet.  */
  50   // mutex->__count = 0;        already done by memset
  51   // mutex->__owner = 0;        already done by memset
  52   // mutex->__nusers = 0;       already done by memset
  53   // mutex->__spins = 0;        already done by memset
  54
  55   return 0;
  56 }
  57 strong_alias (__pthread_mutex_init, pthread_mutex_init)
  58 INTDEF(__pthread_mutex_init)