1/* 2 * pthread_rwlockattr_setpshared.c 3 * 4 * Description: 5 * This translation unit implements read/write lock 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 <limits.h> 38 39#include "pthread.h" 40#include "implement.h" 41 42int 43pthread_rwlockattr_setpshared (pthread_rwlockattr_t * attr, int pshared) 44 /* 45 * ------------------------------------------------------ 46 * DOCPUBLIC 47 * Rwlocks created with 'attr' can be shared between 48 * processes if pthread_rwlock_t variable is allocated 49 * in memory shared by these processes. 50 * 51 * PARAMETERS 52 * attr 53 * pointer to an instance of pthread_rwlockattr_t 54 * 55 * pshared 56 * must be one of: 57 * 58 * PTHREAD_PROCESS_SHARED 59 * May be shared if in shared memory 60 * 61 * PTHREAD_PROCESS_PRIVATE 62 * Cannot be shared. 63 * 64 * DESCRIPTION 65 * Rwlocks creatd with 'attr' can be shared between 66 * processes if pthread_rwlock_t variable is allocated 67 * in memory shared by these processes. 68 * 69 * NOTES: 70 * 1) pshared rwlocks MUST be allocated in shared 71 * memory. 72 * 73 * 2) The following macro is defined if shared rwlocks 74 * are supported: 75 * _POSIX_THREAD_PROCESS_SHARED 76 * 77 * RESULTS 78 * 0 successfully set attribute, 79 * EINVAL 'attr' or pshared is invalid, 80 * ENOSYS PTHREAD_PROCESS_SHARED not supported, 81 * 82 * ------------------------------------------------------ 83 */ 84{ 85 int result; 86 87 if ((attr != NULL && *attr != NULL) && 88 ((pshared == PTHREAD_PROCESS_SHARED) || 89 (pshared == PTHREAD_PROCESS_PRIVATE))) 90 { 91 if (pshared == PTHREAD_PROCESS_SHARED) 92 { 93 94#if !defined( _POSIX_THREAD_PROCESS_SHARED ) 95 96 result = ENOSYS; 97 pshared = PTHREAD_PROCESS_PRIVATE; 98 99#else 100 101 result = 0; 102 103#endif /* _POSIX_THREAD_PROCESS_SHARED */ 104 105 } 106 else 107 { 108 result = 0; 109 } 110 111 (*attr)->pshared = pshared; 112 } 113 else 114 { 115 result = EINVAL; 116 } 117 118 return (result); 119 120} /* pthread_rwlockattr_setpshared */ 121