| /* |
| * Copyright (C) 2006 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.os; |
| |
| /** |
| * Handy class for starting a new thread that has a looper. The looper can then be |
| * used to create handler classes. Note that start() must still be called. |
| */ |
| public class HandlerThread extends Thread { |
| int mPriority; |
| int mTid = -1; |
| Looper mLooper; |
| |
| public HandlerThread(String name) { |
| super(name); |
| mPriority = Process.THREAD_PRIORITY_DEFAULT; |
| } |
| |
| /** |
| * Constructs a HandlerThread. |
| * @param name |
| * @param priority The priority to run the thread at. The value supplied must be from |
| * {@link android.os.Process} and not from java.lang.Thread. |
| */ |
| public HandlerThread(String name, int priority) { |
| super(name); |
| mPriority = priority; |
| } |
| |
| /** |
| * Call back method that can be explicitly overridden if needed to execute some |
| * setup before Looper loops. |
| */ |
| protected void onLooperPrepared() { |
| } |
| |
| @Override |
| public void run() { |
| mTid = Process.myTid(); |
| Looper.prepare(); |
| synchronized (this) { |
| mLooper = Looper.myLooper(); |
| notifyAll(); |
| } |
| Process.setThreadPriority(mPriority); |
| onLooperPrepared(); |
| Looper.loop(); |
| mTid = -1; |
| } |
| |
| /** |
| * This method returns the Looper associated with this thread. If this thread not been started |
| * or for any reason isAlive() returns false, this method will return null. If this thread |
| * has been started, this method will block until the looper has been initialized. |
| * @return The looper. |
| */ |
| public Looper getLooper() { |
| if (!isAlive()) { |
| return null; |
| } |
| |
| // If the thread has been started, wait until the looper has been created. |
| synchronized (this) { |
| while (isAlive() && mLooper == null) { |
| try { |
| wait(); |
| } catch (InterruptedException e) { |
| } |
| } |
| } |
| return mLooper; |
| } |
| |
| /** |
| * Quits the handler thread's looper. |
| * <p> |
| * Causes the handler thread's looper to terminate without processing any |
| * more messages in the message queue. |
| * </p><p> |
| * Any attempt to post messages to the queue after the looper is asked to quit will fail. |
| * For example, the {@link Handler#sendMessage(Message)} method will return false. |
| * </p><p class="note"> |
| * Using this method may be unsafe because some messages may not be delivered |
| * before the looper terminates. Consider using {@link #quitSafely} instead to ensure |
| * that all pending work is completed in an orderly manner. |
| * </p> |
| * |
| * @return True if the looper looper has been asked to quit or false if the |
| * thread had not yet started running. |
| * |
| * @see #quitSafely |
| */ |
| public boolean quit() { |
| Looper looper = getLooper(); |
| if (looper != null) { |
| looper.quit(); |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Quits the handler thread's looper safely. |
| * <p> |
| * Causes the handler thread's looper to terminate as soon as all remaining messages |
| * in the message queue that are already due to be delivered have been handled. |
| * Pending delayed messages with due times in the future will not be delivered. |
| * </p><p> |
| * Any attempt to post messages to the queue after the looper is asked to quit will fail. |
| * For example, the {@link Handler#sendMessage(Message)} method will return false. |
| * </p><p> |
| * If the thread has not been started or has finished (that is if |
| * {@link #getLooper} returns null), then false is returned. |
| * Otherwise the looper is asked to quit and true is returned. |
| * </p> |
| * |
| * @return True if the looper looper has been asked to quit or false if the |
| * thread had not yet started running. |
| */ |
| public boolean quitSafely() { |
| Looper looper = getLooper(); |
| if (looper != null) { |
| looper.quitSafely(); |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Returns the identifier of this thread. See Process.myTid(). |
| */ |
| public int getThreadId() { |
| return mTid; |
| } |
| } |