1 /*
2 * pthread_rwlockattr_setpshared.c
3 *
4 * Description:
5 * This translation unit implements read/write lock primitives.
6 *
7 * --------------------------------------------------------------------------
8 *
9 * Pthreads-embedded (PTE) - POSIX Threads Library for embedded systems
10 * Copyright(C) 2008 Jason Schmidlapp
11 *
12 * Contact Email: jschmidlapp@users.sourceforge.net
13 *
14 *
15 * Based upon Pthreads-win32 - POSIX Threads Library for Win32
16 * Copyright(C) 1998 John E. Bossom
17 * Copyright(C) 1999,2005 Pthreads-win32 contributors
18 *
19 * Contact Email: rpj@callisto.canberra.edu.au
20 *
21 * The original list of contributors to the Pthreads-win32 project
22 * is contained in the file CONTRIBUTORS.ptw32 included with the
23 * source code distribution. The list can also be seen at the
24 * following World Wide Web location:
25 * http://sources.redhat.com/pthreads-win32/contributors.html
26 *
27 * This library is free software; you can redistribute it and/or
28 * modify it under the terms of the GNU Lesser General Public
29 * License as published by the Free Software Foundation; either
30 * version 2 of the License, or (at your option) any later version.
31 *
32 * This library is distributed in the hope that it will be useful,
33 * but WITHOUT ANY WARRANTY; without even the implied warranty of
34 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
35 * Lesser General Public License for more details.
36 *
37 * You should have received a copy of the GNU Lesser General Public
38 * License along with this library in the file COPYING.LIB;
39 * if not, write to the Free Software Foundation, Inc.,
40 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
41 */
42
43 #include <errno.h>
44 #include <limits.h>
45
46 #include "pthread.h"
47 #include "implement.h"
48
49 int
pthread_rwlockattr_setpshared(pthread_rwlockattr_t * attr,int pshared)50 pthread_rwlockattr_setpshared (pthread_rwlockattr_t * attr, int pshared)
51 /*
52 * ------------------------------------------------------
53 * DOCPUBLIC
54 * Rwlocks created with 'attr' can be shared between
55 * processes if pthread_rwlock_t variable is allocated
56 * in memory shared by these processes.
57 *
58 * PARAMETERS
59 * attr
60 * pointer to an instance of pthread_rwlockattr_t
61 *
62 * pshared
63 * must be one of:
64 *
65 * PTHREAD_PROCESS_SHARED
66 * May be shared if in shared memory
67 *
68 * PTHREAD_PROCESS_PRIVATE
69 * Cannot be shared.
70 *
71 * DESCRIPTION
72 * Rwlocks creatd with 'attr' can be shared between
73 * processes if pthread_rwlock_t variable is allocated
74 * in memory shared by these processes.
75 *
76 * NOTES:
77 * 1) pshared rwlocks MUST be allocated in shared
78 * memory.
79 *
80 * 2) The following macro is defined if shared rwlocks
81 * are supported:
82 * _POSIX_THREAD_PROCESS_SHARED
83 *
84 * RESULTS
85 * 0 successfully set attribute,
86 * EINVAL 'attr' or pshared is invalid,
87 * ENOSYS PTHREAD_PROCESS_SHARED not supported,
88 *
89 * ------------------------------------------------------
90 */
91 {
92 int result;
93
94 if ((attr != NULL && *attr != NULL) &&
95 ((pshared == PTHREAD_PROCESS_SHARED) ||
96 (pshared == PTHREAD_PROCESS_PRIVATE)))
97 {
98 if (pshared == PTHREAD_PROCESS_SHARED)
99 {
100
101 #if !defined( _POSIX_THREAD_PROCESS_SHARED )
102
103 result = ENOSYS;
104 pshared = PTHREAD_PROCESS_PRIVATE;
105
106 #else
107
108 result = 0;
109
110 #endif /* _POSIX_THREAD_PROCESS_SHARED */
111
112 }
113 else
114 {
115 result = 0;
116 }
117
118 (*attr)->pshared = pshared;
119 }
120 else
121 {
122 result = EINVAL;
123 }
124
125 return (result);
126
127 } /* pthread_rwlockattr_setpshared */
128