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
40int
41pthread_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}
104