1  /* pthread_mutex_unlock.  Hurd version.
       2     Copyright (C) 2016-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       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     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <pthread.h>
      20  #include <stdlib.h>
      21  #include <assert.h>
      22  #include <pt-internal.h>
      23  #include "pt-mutex.h"
      24  #include <hurdlock.h>
      25  
      26  int
      27  __pthread_mutex_unlock (pthread_mutex_t *mtxp)
      28  {
      29    struct __pthread *self;
      30    int ret = 0, flags = mtxp->__flags & GSYNC_SHARED;
      31  
      32    switch (MTX_TYPE (mtxp))
      33      {
      34      case PT_MTX_NORMAL:
      35        lll_unlock (mtxp->__lock, flags);
      36        break;
      37  
      38      case PT_MTX_RECURSIVE:
      39        self = _pthread_self ();
      40        if (!mtx_owned_p (mtxp, self, flags))
      41  	ret = EPERM;
      42        else if (--mtxp->__cnt == 0)
      43  	{
      44  	  mtxp->__owner_id = mtxp->__shpid = 0;
      45  	  lll_unlock (mtxp->__lock, flags);
      46  	}
      47  
      48        break;
      49  
      50      case PT_MTX_ERRORCHECK:
      51        self = _pthread_self ();
      52        if (!mtx_owned_p (mtxp, self, flags))
      53  	ret = EPERM;
      54        else
      55  	{
      56  	  mtxp->__owner_id = mtxp->__shpid = 0;
      57  	  lll_unlock (mtxp->__lock, flags);
      58  	}
      59  
      60        break;
      61  
      62      case PT_MTX_NORMAL | PTHREAD_MUTEX_ROBUST:
      63      case PT_MTX_RECURSIVE | PTHREAD_MUTEX_ROBUST:
      64      case PT_MTX_ERRORCHECK | PTHREAD_MUTEX_ROBUST:
      65        self = _pthread_self ();
      66        if (mtxp->__owner_id == NOTRECOVERABLE_ID)
      67  	;			/* Nothing to do. */
      68        else if (mtxp->__owner_id != self->thread
      69  	       || (int) (mtxp->__lock & LLL_OWNER_MASK) != __getpid ())
      70  	ret = EPERM;
      71        else if (--mtxp->__cnt == 0)
      72  	{
      73  	  /* Release the lock. If it's in an inconsistent
      74  	   * state, mark it as irrecoverable. */
      75  	  mtxp->__owner_id = ((mtxp->__lock & LLL_DEAD_OWNER)
      76  			      ? NOTRECOVERABLE_ID : 0);
      77  	  lll_robust_unlock (mtxp->__lock, flags);
      78  	}
      79  
      80        break;
      81  
      82      default:
      83        ret = EINVAL;
      84        break;
      85      }
      86  
      87    return ret;
      88  }
      89  
      90  hidden_def (__pthread_mutex_unlock)
      91  strong_alias (__pthread_mutex_unlock, _pthread_mutex_unlock)
      92  weak_alias (__pthread_mutex_unlock, pthread_mutex_unlock)