1 /*
2 * pthread_mutexattr_setpshared.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_setpshared(pthread_mutexattr_t * attr,int pshared)42 pthread_mutexattr_setpshared (pthread_mutexattr_t * attr, int pshared)
43 /*
44 * ------------------------------------------------------
45 * DOCPUBLIC
46 * Mutexes created with 'attr' can be shared between
47 * processes if pthread_mutex_t variable is allocated
48 * in memory shared by these processes.
49 *
50 * PARAMETERS
51 * attr
52 * pointer to an instance of pthread_mutexattr_t
53 *
54 * pshared
55 * must be one of:
56 *
57 * PTHREAD_PROCESS_SHARED
58 * May be shared if in shared memory
59 *
60 * PTHREAD_PROCESS_PRIVATE
61 * Cannot be shared.
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 *
68 * NOTES:
69 * 1) pshared mutexes MUST be allocated in shared
70 * memory.
71 *
72 * 2) The following macro is defined if shared mutexes
73 * are supported:
74 * _POSIX_THREAD_PROCESS_SHARED
75 *
76 * RESULTS
77 * 0 successfully set attribute,
78 * EINVAL 'attr' or pshared is invalid,
79 * ENOSYS PTHREAD_PROCESS_SHARED not supported,
80 *
81 * ------------------------------------------------------
82 */
83 {
84 int result;
85
86 if ((attr != NULL && *attr != NULL) &&
87 ((pshared == PTHREAD_PROCESS_SHARED) ||
88 (pshared == PTHREAD_PROCESS_PRIVATE)))
89 {
90 if (pshared == PTHREAD_PROCESS_SHARED)
91 {
92
93 #if !defined( _POSIX_THREAD_PROCESS_SHARED )
94
95 result = ENOSYS;
96 pshared = PTHREAD_PROCESS_PRIVATE;
97
98 #else
99
100 result = 0;
101
102 #endif /* _POSIX_THREAD_PROCESS_SHARED */
103
104 }
105 else
106 {
107 result = 0;
108 }
109
110 (*attr)->pshared = pshared;
111 }
112 else
113 {
114 result = EINVAL;
115 }
116
117 return (result);
118
119 } /* pthread_mutexattr_setpshared */
120