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      1 /*
      2  * pthread_mutexattr_setrobust.c
      3  *
      4  * Description:
      5  * This translation unit implements mutual exclusion (mutex) 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 (at) 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 
     41 int
     42 pthread_mutexattr_setrobust (pthread_mutexattr_t * attr, int robust)
     43      /*
     44       * ------------------------------------------------------
     45       *
     46       * DOCPUBLIC
     47       * The pthread_mutexattr_setrobust() and
     48       * pthread_mutexattr_getrobust() functions  respectively set and
     49       * get the mutex robust  attribute. This attribute is set in  the
     50       * robust parameter to these functions.
     51       *
     52       * PARAMETERS
     53       *      attr
     54       *              pointer to an instance of pthread_mutexattr_t
     55       *
     56       *     robust
     57       *              must be one of:
     58       *
     59       *                      PTHREAD_MUTEX_STALLED
     60       *
     61       *                      PTHREAD_MUTEX_ROBUST
     62       *
     63       * DESCRIPTION
     64       * The pthread_mutexattr_setrobust() and
     65       * pthread_mutexattr_getrobust() functions  respectively set and
     66       * get the mutex robust  attribute. This attribute is set in  the
     67       * robust  parameter to these functions. The default value of the
     68       * robust  attribute is  PTHREAD_MUTEX_STALLED.
     69       *
     70       * The robustness of mutex is contained in the robustness attribute
     71       * of the mutex attributes. Valid mutex robustness values are:
     72       *
     73       * PTHREAD_MUTEX_STALLED
     74       * No special actions are taken if the owner of the mutex is
     75       * terminated while holding the mutex lock. This can lead to
     76       * deadlocks if no other thread can unlock the mutex.
     77       * This is the default value.
     78       *
     79       * PTHREAD_MUTEX_ROBUST
     80       * If the process containing the owning thread of a robust mutex
     81       * terminates while holding the mutex lock, the next thread that
     82       * acquires the mutex shall be notified about the termination by
     83       * the return value [EOWNERDEAD] from the locking function. If the
     84       * owning thread of a robust mutex terminates while holding the mutex
     85       * lock, the next thread that acquires the mutex may be notified
     86       * about the termination by the return value [EOWNERDEAD]. The
     87       * notified thread can then attempt to mark the state protected by
     88       * the mutex as consistent again by a call to
     89       * pthread_mutex_consistent(). After a subsequent successful call to
     90       * pthread_mutex_unlock(), the mutex lock shall be released and can
     91       * be used normally by other threads. If the mutex is unlocked without
     92       * a call to pthread_mutex_consistent(), it shall be in a permanently
     93       * unusable state and all attempts to lock the mutex shall fail with
     94       * the error [ENOTRECOVERABLE]. The only permissible operation on such
     95       * a mutex is pthread_mutex_destroy().
     96       *
     97       * RESULTS
     98       *              0               successfully set attribute,
     99       *              EINVAL          'attr' or 'robust' is invalid,
    100       *
    101       * ------------------------------------------------------
    102       */
    103 {
    104   int result = EINVAL;
    105 
    106   if ((attr != NULL && *attr != NULL))
    107     {
    108       switch (robust)
    109         {
    110           case PTHREAD_MUTEX_STALLED:
    111           case PTHREAD_MUTEX_ROBUST:
    112 	    (*attr)->robustness = robust;
    113             result = 0;
    114             break;
    115         }
    116     }
    117 
    118   return (result);
    119 }				/* pthread_mutexattr_setrobust */
    120