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glibc  2.9
pthread_barrier_init.c
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00001 /* Copyright (C) 2002, 2007 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #include <errno.h>
00021 #include "pthreadP.h"
00022 #include <lowlevellock.h>
00023 #include <kernel-features.h>
00024 
00025 
00026 static const struct pthread_barrierattr default_attr =
00027   {
00028     .pshared = PTHREAD_PROCESS_PRIVATE
00029   };
00030 
00031 
00032 int
00033 pthread_barrier_init (barrier, attr, count)
00034      pthread_barrier_t *barrier;
00035      const pthread_barrierattr_t *attr;
00036      unsigned int count;
00037 {
00038   struct pthread_barrier *ibarrier;
00039 
00040   if (__builtin_expect (count == 0, 0))
00041     return EINVAL;
00042 
00043   const struct pthread_barrierattr *iattr
00044     = (attr != NULL
00045        ? iattr = (struct pthread_barrierattr *) attr
00046        : &default_attr);
00047 
00048   if (iattr->pshared != PTHREAD_PROCESS_PRIVATE
00049       && __builtin_expect (iattr->pshared != PTHREAD_PROCESS_SHARED, 0))
00050     /* Invalid attribute.  */
00051     return EINVAL;
00052 
00053   ibarrier = (struct pthread_barrier *) barrier;
00054 
00055   /* Initialize the individual fields.  */
00056   ibarrier->lock = LLL_LOCK_INITIALIZER;
00057   ibarrier->left = count;
00058   ibarrier->init_count = count;
00059   ibarrier->curr_event = 0;
00060 
00061 #ifdef __ASSUME_PRIVATE_FUTEX
00062   ibarrier->private = (iattr->pshared != PTHREAD_PROCESS_PRIVATE
00063                      ? 0 : FUTEX_PRIVATE_FLAG);
00064 #else
00065   ibarrier->private = (iattr->pshared != PTHREAD_PROCESS_PRIVATE
00066                      ? 0 : THREAD_GETMEM (THREAD_SELF,
00067                                        header.private_futex));
00068 #endif
00069 
00070   return 0;
00071 }