1 /* 2 * pthread_mutex_unlock.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_mutex_unlock (pthread_mutex_t * mutex) 43 { 44 int result = 0; 45 int kind; 46 pthread_mutex_t mx; 47 48 /* 49 * Let the system deal with invalid pointers. 50 */ 51 52 mx = *mutex; 53 54 /* 55 * If the thread calling us holds the mutex then there is no 56 * race condition. If another thread holds the 57 * lock then we shouldn't be in here. 58 */ 59 if (mx < PTHREAD_ERRORCHECK_MUTEX_INITIALIZER) 60 { 61 kind = mx->kind; 62 63 if (kind >= 0) 64 { 65 if (kind == PTHREAD_MUTEX_NORMAL) 66 { 67 LONG idx; 68 69 idx = (LONG) PTW32_INTERLOCKED_EXCHANGE_LONG ((PTW32_INTERLOCKED_LONGPTR)&mx->lock_idx, 70 (PTW32_INTERLOCKED_LONG)0); 71 if (idx != 0) 72 { 73 if (idx < 0) 74 { 75 /* 76 * Someone may be waiting on that mutex. 77 */ 78 if (SetEvent (mx->event) == 0) 79 { 80 result = EINVAL; 81 } 82 } 83 } 84 } 85 else 86 { 87 if (pthread_equal (mx->ownerThread, pthread_self())) 88 { 89 if (kind != PTHREAD_MUTEX_RECURSIVE 90 || 0 == --mx->recursive_count) 91 { 92 mx->ownerThread.p = NULL; 93 94 if ((LONG) PTW32_INTERLOCKED_EXCHANGE_LONG ((PTW32_INTERLOCKED_LONGPTR)&mx->lock_idx, 95 (PTW32_INTERLOCKED_LONG)0) < 0L) 96 { 97 /* Someone may be waiting on that mutex */ 98 if (SetEvent (mx->event) == 0) 99 { 100 result = EINVAL; 101 } 102 } 103 } 104 } 105 else 106 { 107 result = EPERM; 108 } 109 } 110 } 111 else 112 { 113 /* Robust types */ 114 pthread_t self = pthread_self(); 115 kind = -kind - 1; /* Convert to non-robust range */ 116 117 /* 118 * The thread must own the lock regardless of type if the mutex 119 * is robust. 120 */ 121 if (pthread_equal (mx->ownerThread, self)) 122 { 123 PTW32_INTERLOCKED_COMPARE_EXCHANGE_LONG((PTW32_INTERLOCKED_LONGPTR) &mx->robustNode->stateInconsistent, 124 (PTW32_INTERLOCKED_LONG)PTW32_ROBUST_NOTRECOVERABLE, 125 (PTW32_INTERLOCKED_LONG)PTW32_ROBUST_INCONSISTENT); 126 if (PTHREAD_MUTEX_NORMAL == kind) 127 { 128 ptw32_robust_mutex_remove(mutex, NULL); 129 130 if ((LONG) PTW32_INTERLOCKED_EXCHANGE_LONG((PTW32_INTERLOCKED_LONGPTR) &mx->lock_idx, 131 (PTW32_INTERLOCKED_LONG) 0) < 0) 132 { 133 /* 134 * Someone may be waiting on that mutex. 135 */ 136 if (SetEvent (mx->event) == 0) 137 { 138 result = EINVAL; 139 } 140 } 141 } 142 else 143 { 144 if (kind != PTHREAD_MUTEX_RECURSIVE 145 || 0 == --mx->recursive_count) 146 { 147 ptw32_robust_mutex_remove(mutex, NULL); 148 149 if ((LONG) PTW32_INTERLOCKED_EXCHANGE_LONG((PTW32_INTERLOCKED_LONGPTR) &mx->lock_idx, 150 (PTW32_INTERLOCKED_LONG) 0) < 0) 151 { 152 /* 153 * Someone may be waiting on that mutex. 154 */ 155 if (SetEvent (mx->event) == 0) 156 { 157 result = EINVAL; 158 } 159 } 160 } 161 } 162 } 163 else 164 { 165 result = EPERM; 166 } 167 } 168 } 169 else if (mx != PTHREAD_MUTEX_INITIALIZER) 170 { 171 result = EINVAL; 172 } 173 174 return (result); 175 } 176
