1 /*
2 * pthread_mutexattr_getpshared.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
41 int
pthread_mutexattr_getpshared(const pthread_mutexattr_t * attr,int * pshared)42 pthread_mutexattr_getpshared (const pthread_mutexattr_t * attr, int *pshared)
43 /*
44 * ------------------------------------------------------
45 * DOCPUBLIC
46 * Determine whether mutexes created with 'attr' can be
47 * shared between processes.
48 *
49 * PARAMETERS
50 * attr
51 * pointer to an instance of pthread_mutexattr_t
52 *
53 * pshared
54 * will be set to one of:
55 *
56 * PTHREAD_PROCESS_SHARED
57 * May be shared if in shared memory
58 *
59 * PTHREAD_PROCESS_PRIVATE
60 * Cannot be shared.
61 *
62 *
63 * DESCRIPTION
64 * Mutexes creatd with 'attr' can be shared between
65 * processes if pthread_mutex_t variable is allocated
66 * in memory shared by these processes.
67 * NOTES:
68 * 1) pshared mutexes MUST be allocated in shared
69 * memory.
70 * 2) The following macro is defined if shared mutexes
71 * are supported:
72 * _POSIX_THREAD_PROCESS_SHARED
73 *
74 * RESULTS
75 * 0 successfully retrieved attribute,
76 * EINVAL 'attr' is invalid,
77 *
78 * ------------------------------------------------------
79 */
80 {
81 int result;
82
83 if ((attr != NULL && *attr != NULL) && (pshared != NULL))
84 {
85 *pshared = (*attr)->pshared;
86 result = 0;
87 }
88 else
89 {
90 result = EINVAL;
91 }
92
93 return (result);
94
95 } /* pthread_mutexattr_getpshared */
96