1 /* 2 * ptw32_mutex_check_need_init.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 static struct pthread_mutexattr_t_ ptw32_recursive_mutexattr_s = 41 {PTHREAD_PROCESS_PRIVATE, PTHREAD_MUTEX_RECURSIVE}; 42 static struct pthread_mutexattr_t_ ptw32_errorcheck_mutexattr_s = 43 {PTHREAD_PROCESS_PRIVATE, PTHREAD_MUTEX_ERRORCHECK}; 44 static pthread_mutexattr_t ptw32_recursive_mutexattr = &ptw32_recursive_mutexattr_s; 45 static pthread_mutexattr_t ptw32_errorcheck_mutexattr = &ptw32_errorcheck_mutexattr_s; 46 47 48 INLINE int 49 ptw32_mutex_check_need_init (pthread_mutex_t * mutex) 50 { 51 register int result = 0; 52 register pthread_mutex_t mtx; 53 ptw32_mcs_local_node_t node; 54 55 ptw32_mcs_lock_acquire(&ptw32_mutex_test_init_lock, &node); 56 57 /* 58 * We got here possibly under race 59 * conditions. Check again inside the critical section 60 * and only initialise if the mutex is valid (not been destroyed). 61 * If a static mutex has been destroyed, the application can 62 * re-initialise it only by calling pthread_mutex_init() 63 * explicitly. 64 */ 65 mtx = *mutex; 66 67 if (mtx == PTHREAD_MUTEX_INITIALIZER) 68 { 69 result = pthread_mutex_init (mutex, NULL); 70 } 71 else if (mtx == PTHREAD_RECURSIVE_MUTEX_INITIALIZER) 72 { 73 result = pthread_mutex_init (mutex, &ptw32_recursive_mutexattr); 74 } 75 else if (mtx == PTHREAD_ERRORCHECK_MUTEX_INITIALIZER) 76 { 77 result = pthread_mutex_init (mutex, &ptw32_errorcheck_mutexattr); 78 } 79 else if (mtx == NULL) 80 { 81 /* 82 * The mutex has been destroyed while we were waiting to 83 * initialise it, so the operation that caused the 84 * auto-initialisation should fail. 85 */ 86 result = EINVAL; 87 } 88 89 ptw32_mcs_lock_release(&node); 90 91 return (result); 92 } 93
