summaryrefslogtreecommitdiff
path: root/sysdeps/mach/hurd/pt-mutex-unlock.c
blob: 071f62244b0fcde4d50ffed42480f32ee2d2009a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
/* Copyright (C) 2016 Free Software Foundation, Inc.
   Contributed by Agustina Arzille <avarzille@riseup.net>, 2016.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License
   as published by the Free Software Foundation; either
   version 2 of the license, or (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   GNU Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this program; if not, see
   <http://www.gnu.org/licenses/>.
*/

#include <pthread.h>
#include <stdlib.h>
#include <assert.h>
#include <pt-internal.h>
#include "pt-mutex.h"
#include <hurdlock.h>

int __pthread_mutex_unlock (pthread_mutex_t *mtxp)
{
  struct __pthread *self;
  int ret = 0, flags = mtxp->__flags & GSYNC_SHARED;

  switch (MTX_TYPE (mtxp))
    {
      case PT_MTX_NORMAL:
        lll_unlock (&mtxp->__lock, flags);
        break;

      case PT_MTX_RECURSIVE:
        self = _pthread_self ();
        if (!mtx_owned_p (mtxp, self, flags))
          ret = EPERM;
        else if (--mtxp->__cnt == 0)
          {
            mtxp->__owner_id = mtxp->__shpid = 0;
            lll_unlock (&mtxp->__lock, flags);
          }

        break;

      case PT_MTX_ERRORCHECK:
        self = _pthread_self ();
        if (!mtx_owned_p (mtxp, self, flags))
          ret = EPERM;
        else
          {
            mtxp->__owner_id = mtxp->__shpid = 0;
            lll_unlock (&mtxp->__lock, flags);
          }

        break;

      case PT_MTX_NORMAL     | PTHREAD_MUTEX_ROBUST:
      case PT_MTX_RECURSIVE  | PTHREAD_MUTEX_ROBUST:
      case PT_MTX_ERRORCHECK | PTHREAD_MUTEX_ROBUST:
        self = _pthread_self ();
        if (mtxp->__owner_id == NOTRECOVERABLE_ID)
          ;   /* Nothing to do. */
        else if (mtxp->__owner_id != self->thread ||
            (int)(mtxp->__lock & LLL_OWNER_MASK) != __getpid ())
          ret = EPERM;
        else if (--mtxp->__cnt == 0)
          {
            /* Release the lock. If it's in an inconsistent
             * state, mark it as irrecoverable. */
            mtxp->__owner_id = (mtxp->__lock & LLL_DEAD_OWNER) ?
              NOTRECOVERABLE_ID : 0;
            __lll_robust_unlock (&mtxp->__lock, flags);
          }

        break;

      default:
        ret = EINVAL;
        break;
    }

  return (ret);
}

strong_alias (__pthread_mutex_unlock, _pthread_mutex_unlock)
strong_alias (__pthread_mutex_unlock, pthread_mutex_unlock)