nptl/pthread_barrier_init.c

   1 /* Copyright (C) 2002-2017 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include "pthreadP.h"
  21 #include <futex-internal.h>
  22 #include <kernel-features.h>
  23
  24
  25 static const struct pthread_barrierattr default_barrierattr =
  26   {
  27     .pshared = PTHREAD_PROCESS_PRIVATE
  28   };
  29
  30
  31 int
  32 __pthread_barrier_init (pthread_barrier_t *barrier,
  33                         const pthread_barrierattr_t *attr, unsigned int count)
  34 {
  35   ASSERT_TYPE_SIZE (pthread_barrier_t, __SIZEOF_PTHREAD_BARRIER_T);
  36   ASSERT_PTHREAD_INTERNAL_SIZE (pthread_barrier_t,
  37                                 struct pthread_barrier);
  38
  39   struct pthread_barrier *ibarrier;
  40
  41   /* XXX EINVAL is not specified by POSIX as a possible error code for COUNT
  42      being too large.  See pthread_barrier_wait for the reason for the
  43      comparison with BARRIER_IN_THRESHOLD.  */
  44   if (__glibc_unlikely (count == 0 || count >= BARRIER_IN_THRESHOLD))
  45     return EINVAL;
  46
  47   const struct pthread_barrierattr *iattr
  48     = (attr != NULL
  49        ? (struct pthread_barrierattr *) attr
  50        : &default_barrierattr);
  51
  52   ibarrier = (struct pthread_barrier *) barrier;
  53
  54   /* Initialize the individual fields.  */
  55   ibarrier->in = 0;
  56   ibarrier->out = 0;
  57   ibarrier->count = count;
  58   ibarrier->current_round = 0;
  59   ibarrier->shared = (iattr->pshared == PTHREAD_PROCESS_PRIVATE
  60                       ? FUTEX_PRIVATE : FUTEX_SHARED);
  61
  62   return 0;
  63 }
  64 weak_alias (__pthread_barrier_init, pthread_barrier_init)