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 (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_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
