native_client_sdk/src/libraries/third_party/pthreads-win32/pthread_barrier_destroy.c

   1 /*
   2  * pthread_barrier_destroy.c
   3  *
   4  * Description:
   5  * This translation unit implements barrier primitives.
   6  *
   7  * --------------------------------------------------------------------------
   8  *
   9  *      Pthreads-win32 - POSIX Threads Library for Win32
  10  *      Copyright(C) 1998 John E. Bossom
  11  *      Copyright(C) 1999,2005 Pthreads-win32 contributors
  12  *
  13  *      Contact Email: rpj@callisto.canberra.edu.au
  14  *
  15  *      The current list of contributors is contained
  16  *      in the file CONTRIBUTORS included with the source
  17  *      code distribution. The list can also be seen at the
  18  *      following World Wide Web location:
  19  *      http://sources.redhat.com/pthreads-win32/contributors.html
  20  *
  21  *      This library is free software; you can redistribute it and/or
  22  *      modify it under the terms of the GNU Lesser General Public
  23  *      License as published by the Free Software Foundation; either
  24  *      version 2 of the License, or (at your option) any later version.
  25  *
  26  *      This library is distributed in the hope that it will be useful,
  27  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  29  *      Lesser General Public License for more details.
  30  *
  31  *      You should have received a copy of the GNU Lesser General Public
  32  *      License along with this library in the file COPYING.LIB;
  33  *      if not, write to the Free Software Foundation, Inc.,
  34  *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  35  */
  36
  37 #include "pthread.h"
  38 #include "implement.h"
  39
  40 int
  41 pthread_barrier_destroy (pthread_barrier_t * barrier)
  42 {
  43   int result = 0;
  44   pthread_barrier_t b;
  45   ptw32_mcs_local_node_t node;
  46
  47   if (barrier == NULL || *barrier == (pthread_barrier_t) PTW32_OBJECT_INVALID)
  48     {
  49       return EINVAL;
  50     }
  51
  52   if (0 != ptw32_mcs_lock_try_acquire(&(*barrier)->lock, &node))
  53     {
  54       return EBUSY;
  55     }
  56
  57   b = *barrier;
  58
  59   if (b->nCurrentBarrierHeight < b->nInitialBarrierHeight)
  60     {
  61       result = EBUSY;
  62     }
  63   else
  64         {
  65       if (0 == (result = sem_destroy (&(b->semBarrierBreeched))))
  66         {
  67           *barrier = (pthread_barrier_t) PTW32_OBJECT_INVALID;
  68           /*
  69            * Release the lock before freeing b.
  70            *
  71            * FIXME: There may be successors which, when we release the lock,
  72            * will be linked into b->lock, which will be corrupted at some
  73            * point with undefined results for the application. To fix this
  74            * will require changing pthread_barrier_t from a pointer to
  75            * pthread_barrier_t_ to an instance. This is a change to the ABI
  76            * and will require a major version number increment.
  77            */
  78           ptw32_mcs_lock_release(&node);
  79           (void) free (b);
  80           return 0;
  81         }
  82       else
  83         {
  84           /*
  85            * This should not ever be reached.
  86            * Restore the barrier to working condition before returning.
  87            */
  88           (void) sem_init (&(b->semBarrierBreeched), b->pshared, 0);
  89         }
  90
  91       if (result != 0)
  92         {
  93           /*
  94            * The barrier still exists and is valid
  95            * in the event of any error above.
  96            */
  97           result = EBUSY;
  98         }
  99     }
 100
 101   ptw32_mcs_lock_release(&node);
 102   return (result);
 103 }