1/*
2 * pthread_mutexattr_getrobust.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@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
41int
42pthread_mutexattr_getrobust (const 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 && robust != NULL))
107    {
108      *robust = (*attr)->robustness;
109      result = 0;
110    }
111
112  return (result);
113}				/* pthread_mutexattr_getrobust */
114