1676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org/* 2ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com * pthread_mutex_destroy.c 3ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com * 4ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com * Description: 5ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com * This translation unit implements mutual exclusion (mutex) primitives. 6ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com * 7676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * -------------------------------------------------------------------------- 8676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * 9ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976eepoger@google.com * Pthreads-win32 - POSIX Threads Library for Win32 10676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * Copyright(C) 1998 John E. Bossom 11676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * Copyright(C) 1999,2005 Pthreads-win32 contributors 12676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * 13676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * Contact Email: rpj@callisto.canberra.edu.au 14676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * 15676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * The current list of contributors is contained 16676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * in the file CONTRIBUTORS included with the source 17676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * code distribution. The list can also be seen at the 18676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * following World Wide Web location: 19676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * http://sources.redhat.com/pthreads-win32/contributors.html 20676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * 21676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * This library is free software; you can redistribute it and/or 22676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * modify it under the terms of the GNU Lesser General Public 23676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * License as published by the Free Software Foundation; either 24676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * version 2 of the License, or (at your option) any later version. 25676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * 26676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * This library is distributed in the hope that it will be useful, 2763c1ad82fc4232daff1b686cc78bba4c6a42916dreed@google.com * but WITHOUT ANY WARRANTY; without even the implied warranty of 2863c1ad82fc4232daff1b686cc78bba4c6a42916dreed@google.com * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 29676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * Lesser General Public License for more details. 30676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * 31676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org * You should have received a copy of the GNU Lesser General Public 3213659f1f8d2e705c565203d45870b1afcd47cf98reed@google.com * License along with this library in the file COPYING.LIB; 3313659f1f8d2e705c565203d45870b1afcd47cf98reed@google.com * if not, write to the Free Software Foundation, Inc., 3413659f1f8d2e705c565203d45870b1afcd47cf98reed@google.com * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 35676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org */ 36676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org 37676d69b82f2e2c6bf743ff8c7fbb436f36a004e2mike@reedtribe.org#include "pthread.h" 38#include "implement.h" 39 40 41int 42pthread_mutex_destroy (pthread_mutex_t * mutex) 43{ 44 int result = 0; 45 pthread_mutex_t mx; 46 47 /* 48 * Let the system deal with invalid pointers. 49 */ 50 51 /* 52 * Check to see if we have something to delete. 53 */ 54 if (*mutex < PTHREAD_ERRORCHECK_MUTEX_INITIALIZER) 55 { 56 mx = *mutex; 57 58 result = pthread_mutex_trylock (&mx); 59 60 /* 61 * If trylock succeeded and the mutex is not recursively locked it 62 * can be destroyed. 63 */ 64 if (0 == result || ENOTRECOVERABLE == result) 65 { 66 if (mx->kind != PTHREAD_MUTEX_RECURSIVE || 1 == mx->recursive_count) 67 { 68 /* 69 * FIXME!!! 70 * The mutex isn't held by another thread but we could still 71 * be too late invalidating the mutex below since another thread 72 * may already have entered mutex_lock and the check for a valid 73 * *mutex != NULL. 74 */ 75 *mutex = NULL; 76 77 result = (0 == result)?pthread_mutex_unlock(&mx):0; 78 79 if (0 == result) 80 { 81 if (mx->robustNode != NULL) 82 { 83 free(mx->robustNode); 84 } 85 if (!CloseHandle (mx->event)) 86 { 87 *mutex = mx; 88 result = EINVAL; 89 } 90 else 91 { 92 free (mx); 93 } 94 } 95 else 96 { 97 /* 98 * Restore the mutex before we return the error. 99 */ 100 *mutex = mx; 101 } 102 } 103 else /* mx->recursive_count > 1 */ 104 { 105 /* 106 * The mutex must be recursive and already locked by us (this thread). 107 */ 108 mx->recursive_count--; /* Undo effect of pthread_mutex_trylock() above */ 109 result = EBUSY; 110 } 111 } 112 } 113 else 114 { 115 ptw32_mcs_local_node_t node; 116 117 /* 118 * See notes in ptw32_mutex_check_need_init() above also. 119 */ 120 121 ptw32_mcs_lock_acquire(&ptw32_mutex_test_init_lock, &node); 122 123 /* 124 * Check again. 125 */ 126 if (*mutex >= PTHREAD_ERRORCHECK_MUTEX_INITIALIZER) 127 { 128 /* 129 * This is all we need to do to destroy a statically 130 * initialised mutex that has not yet been used (initialised). 131 * If we get to here, another thread 132 * waiting to initialise this mutex will get an EINVAL. 133 */ 134 *mutex = NULL; 135 } 136 else 137 { 138 /* 139 * The mutex has been initialised while we were waiting 140 * so assume it's in use. 141 */ 142 result = EBUSY; 143 } 144 ptw32_mcs_lock_release(&node); 145 } 146 147 return (result); 148} 149