1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * 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 //#define LOG_NDEBUG 0 18 #define LOG_TAG "ALooperRoster" 19 #include <utils/Log.h> 20 21 #include "ALooperRoster.h" 22 23 #include "ADebug.h" 24 #include "AHandler.h" 25 #include "AMessage.h" 26 27 namespace android { 28 29 ALooperRoster::ALooperRoster() 30 : mNextHandlerID(1), 31 mNextReplyID(1) { 32 } 33 34 ALooper::handler_id ALooperRoster::registerHandler( 35 const sp<ALooper> looper, const sp<AHandler> &handler) { 36 Mutex::Autolock autoLock(mLock); 37 38 if (handler->id() != 0) { 39 CHECK(!"A handler must only be registered once."); 40 return INVALID_OPERATION; 41 } 42 43 HandlerInfo info; 44 info.mLooper = looper; 45 info.mHandler = handler; 46 ALooper::handler_id handlerID = mNextHandlerID++; 47 mHandlers.add(handlerID, info); 48 49 handler->setID(handlerID); 50 51 return handlerID; 52 } 53 54 void ALooperRoster::unregisterHandler(ALooper::handler_id handlerID) { 55 Mutex::Autolock autoLock(mLock); 56 57 ssize_t index = mHandlers.indexOfKey(handlerID); 58 59 if (index < 0) { 60 return; 61 } 62 63 const HandlerInfo &info = mHandlers.valueAt(index); 64 65 sp<AHandler> handler = info.mHandler.promote(); 66 67 if (handler != NULL) { 68 handler->setID(0); 69 } 70 71 mHandlers.removeItemsAt(index); 72 } 73 74 void ALooperRoster::unregisterStaleHandlers() { 75 76 Vector<sp<ALooper> > activeLoopers; 77 { 78 Mutex::Autolock autoLock(mLock); 79 80 for (size_t i = mHandlers.size(); i-- > 0;) { 81 const HandlerInfo &info = mHandlers.valueAt(i); 82 83 sp<ALooper> looper = info.mLooper.promote(); 84 if (looper == NULL) { 85 ALOGV("Unregistering stale handler %d", mHandlers.keyAt(i)); 86 mHandlers.removeItemsAt(i); 87 } else { 88 // At this point 'looper' might be the only sp<> keeping 89 // the object alive. To prevent it from going out of scope 90 // and having ~ALooper call this method again recursively 91 // and then deadlocking because of the Autolock above, add 92 // it to a Vector which will go out of scope after the lock 93 // has been released. 94 activeLoopers.add(looper); 95 } 96 } 97 } 98 } 99 100 status_t ALooperRoster::postMessage( 101 const sp<AMessage> &msg, int64_t delayUs) { 102 103 sp<ALooper> looper = findLooper(msg->target()); 104 105 if (looper == NULL) { 106 return -ENOENT; 107 } 108 looper->post(msg, delayUs); 109 return OK; 110 } 111 112 void ALooperRoster::deliverMessage(const sp<AMessage> &msg) { 113 sp<AHandler> handler; 114 115 { 116 Mutex::Autolock autoLock(mLock); 117 118 ssize_t index = mHandlers.indexOfKey(msg->target()); 119 120 if (index < 0) { 121 ALOGW("failed to deliver message. Target handler not registered."); 122 return; 123 } 124 125 const HandlerInfo &info = mHandlers.valueAt(index); 126 handler = info.mHandler.promote(); 127 128 if (handler == NULL) { 129 ALOGW("failed to deliver message. " 130 "Target handler %d registered, but object gone.", 131 msg->target()); 132 133 mHandlers.removeItemsAt(index); 134 return; 135 } 136 } 137 138 handler->onMessageReceived(msg); 139 } 140 141 sp<ALooper> ALooperRoster::findLooper(ALooper::handler_id handlerID) { 142 Mutex::Autolock autoLock(mLock); 143 144 ssize_t index = mHandlers.indexOfKey(handlerID); 145 146 if (index < 0) { 147 return NULL; 148 } 149 150 sp<ALooper> looper = mHandlers.valueAt(index).mLooper.promote(); 151 152 if (looper == NULL) { 153 mHandlers.removeItemsAt(index); 154 return NULL; 155 } 156 157 return looper; 158 } 159 160 status_t ALooperRoster::postAndAwaitResponse( 161 const sp<AMessage> &msg, sp<AMessage> *response) { 162 sp<ALooper> looper = findLooper(msg->target()); 163 164 if (looper == NULL) { 165 ALOGW("failed to post message. " 166 "Target handler %d still registered, but object gone.", 167 msg->target()); 168 response->clear(); 169 return -ENOENT; 170 } 171 172 Mutex::Autolock autoLock(mLock); 173 174 uint32_t replyID = mNextReplyID++; 175 176 msg->setInt32("replyID", replyID); 177 178 looper->post(msg, 0 /* delayUs */); 179 180 ssize_t index; 181 while ((index = mReplies.indexOfKey(replyID)) < 0) { 182 mRepliesCondition.wait(mLock); 183 } 184 185 *response = mReplies.valueAt(index); 186 mReplies.removeItemsAt(index); 187 188 return OK; 189 } 190 191 void ALooperRoster::postReply(uint32_t replyID, const sp<AMessage> &reply) { 192 Mutex::Autolock autoLock(mLock); 193 194 CHECK(mReplies.indexOfKey(replyID) < 0); 195 mReplies.add(replyID, reply); 196 mRepliesCondition.broadcast(); 197 } 198 199 } // namespace android 200
