1/* Licensed to the Apache Software Foundation (ASF) under one or more 2 * contributor license agreements. See the NOTICE file distributed with 3 * this work for additional information regarding copyright ownership. 4 * The ASF licenses this file to You under the Apache License, Version 2.0 5 * (the "License"); you may not use this file except in compliance with 6 * the License. You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "apr.h" 18#include "apr_private.h" 19#include "apr_general.h" 20#include "apr_strings.h" 21#include "apr_arch_thread_mutex.h" 22#include "apr_arch_thread_cond.h" 23#include "apr_portable.h" 24 25#include <limits.h> 26 27static apr_status_t thread_cond_cleanup(void *data) 28{ 29 apr_thread_cond_t *cond = data; 30 CloseHandle(cond->semaphore); 31 DeleteCriticalSection(&cond->csection); 32 return APR_SUCCESS; 33} 34 35APR_DECLARE(apr_status_t) apr_thread_cond_create(apr_thread_cond_t **cond, 36 apr_pool_t *pool) 37{ 38 apr_thread_cond_t *cv; 39 40 cv = apr_pcalloc(pool, sizeof(**cond)); 41 if (cv == NULL) { 42 return APR_ENOMEM; 43 } 44 45 cv->semaphore = CreateSemaphore(NULL, 0, LONG_MAX, NULL); 46 if (cv->semaphore == NULL) { 47 return apr_get_os_error(); 48 } 49 50 *cond = cv; 51 cv->pool = pool; 52 InitializeCriticalSection(&cv->csection); 53 apr_pool_cleanup_register(cv->pool, cv, thread_cond_cleanup, 54 apr_pool_cleanup_null); 55 56 return APR_SUCCESS; 57} 58 59APR_DECLARE(apr_status_t) apr_thread_cond_destroy(apr_thread_cond_t *cond) 60{ 61 return apr_pool_cleanup_run(cond->pool, cond, thread_cond_cleanup); 62} 63 64static APR_INLINE apr_status_t _thread_cond_timedwait(apr_thread_cond_t *cond, 65 apr_thread_mutex_t *mutex, 66 DWORD timeout_ms ) 67{ 68 DWORD res; 69 apr_status_t rv; 70 unsigned int wake = 0; 71 unsigned long generation; 72 73 EnterCriticalSection(&cond->csection); 74 cond->num_waiting++; 75 generation = cond->generation; 76 LeaveCriticalSection(&cond->csection); 77 78 apr_thread_mutex_unlock(mutex); 79 80 do { 81 res = WaitForSingleObject(cond->semaphore, timeout_ms); 82 83 EnterCriticalSection(&cond->csection); 84 85 if (cond->num_wake) { 86 if (cond->generation != generation) { 87 cond->num_wake--; 88 cond->num_waiting--; 89 rv = APR_SUCCESS; 90 break; 91 } else { 92 wake = 1; 93 } 94 } 95 else if (res != WAIT_OBJECT_0) { 96 cond->num_waiting--; 97 rv = APR_TIMEUP; 98 break; 99 } 100 101 LeaveCriticalSection(&cond->csection); 102 103 if (wake) { 104 wake = 0; 105 ReleaseSemaphore(cond->semaphore, 1, NULL); 106 } 107 } while (1); 108 109 LeaveCriticalSection(&cond->csection); 110 apr_thread_mutex_lock(mutex); 111 112 return rv; 113} 114 115APR_DECLARE(apr_status_t) apr_thread_cond_wait(apr_thread_cond_t *cond, 116 apr_thread_mutex_t *mutex) 117{ 118 return _thread_cond_timedwait(cond, mutex, INFINITE); 119} 120 121APR_DECLARE(apr_status_t) apr_thread_cond_timedwait(apr_thread_cond_t *cond, 122 apr_thread_mutex_t *mutex, 123 apr_interval_time_t timeout) 124{ 125 DWORD timeout_ms = (DWORD) apr_time_as_msec(timeout); 126 127 return _thread_cond_timedwait(cond, mutex, timeout_ms); 128} 129 130APR_DECLARE(apr_status_t) apr_thread_cond_signal(apr_thread_cond_t *cond) 131{ 132 unsigned int wake = 0; 133 134 EnterCriticalSection(&cond->csection); 135 if (cond->num_waiting > cond->num_wake) { 136 wake = 1; 137 cond->num_wake++; 138 cond->generation++; 139 } 140 LeaveCriticalSection(&cond->csection); 141 142 if (wake) { 143 ReleaseSemaphore(cond->semaphore, 1, NULL); 144 } 145 146 return APR_SUCCESS; 147} 148 149APR_DECLARE(apr_status_t) apr_thread_cond_broadcast(apr_thread_cond_t *cond) 150{ 151 unsigned long num_wake = 0; 152 153 EnterCriticalSection(&cond->csection); 154 if (cond->num_waiting > cond->num_wake) { 155 num_wake = cond->num_waiting - cond->num_wake; 156 cond->num_wake = cond->num_waiting; 157 cond->generation++; 158 } 159 LeaveCriticalSection(&cond->csection); 160 161 if (num_wake) { 162 ReleaseSemaphore(cond->semaphore, num_wake, NULL); 163 } 164 165 return APR_SUCCESS; 166} 167 168APR_POOL_IMPLEMENT_ACCESSOR(thread_cond) 169