| /* |
| * Copyright (C) 2009 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 com.android.quicksearchbox.util; |
| |
| import android.util.Log; |
| |
| import java.util.concurrent.LinkedBlockingQueue; |
| import java.util.concurrent.ThreadFactory; |
| |
| /** |
| * Executor that uses a single thread and an unbounded work queue. |
| */ |
| public class SingleThreadNamedTaskExecutor implements NamedTaskExecutor { |
| |
| private static final boolean DBG = false; |
| private static final String TAG = "QSB.SingleThreadNamedTaskExecutor"; |
| |
| private final LinkedBlockingQueue<NamedTask> mQueue; |
| private final Thread mWorker; |
| private volatile boolean mClosed = false; |
| |
| public SingleThreadNamedTaskExecutor(ThreadFactory threadFactory) { |
| mQueue = new LinkedBlockingQueue<NamedTask>(); |
| mWorker = threadFactory.newThread(new Worker()); |
| mWorker.start(); |
| } |
| |
| public void cancelPendingTasks() { |
| if (DBG) Log.d(TAG, "Cancelling " + mQueue.size() + " tasks: " + mWorker.getName()); |
| if (mClosed) { |
| throw new IllegalStateException("cancelPendingTasks() after close()"); |
| } |
| mQueue.clear(); |
| } |
| |
| public void close() { |
| mClosed = true; |
| mWorker.interrupt(); |
| mQueue.clear(); |
| } |
| |
| public void execute(NamedTask task) { |
| if (mClosed) { |
| throw new IllegalStateException("execute() after close()"); |
| } |
| mQueue.add(task); |
| } |
| |
| private class Worker implements Runnable { |
| public void run() { |
| try { |
| loop(); |
| } finally { |
| if (!mClosed) Log.w(TAG, "Worker exited before close"); |
| } |
| } |
| |
| private void loop() { |
| Thread currentThread = Thread.currentThread(); |
| String threadName = currentThread.getName(); |
| while (!mClosed) { |
| NamedTask task; |
| try { |
| task = mQueue.take(); |
| } catch (InterruptedException ex) { |
| continue; |
| } |
| currentThread.setName(threadName + " " + task.getName()); |
| try { |
| if (DBG) Log.d(TAG, "Running task " + task.getName()); |
| task.run(); |
| if (DBG) Log.d(TAG, "Task " + task.getName() + " complete"); |
| } catch (RuntimeException ex) { |
| Log.e(TAG, "Task " + task.getName() + " failed", ex); |
| } |
| } |
| } |
| } |
| |
| public static Factory<NamedTaskExecutor> factory(final ThreadFactory threadFactory) { |
| return new Factory<NamedTaskExecutor>() { |
| public NamedTaskExecutor create() { |
| return new SingleThreadNamedTaskExecutor(threadFactory); |
| } |
| }; |
| } |
| |
| } |