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
17package com.android.quicksearchbox.util;
18
19import java.util.LinkedList;
20import java.util.concurrent.Executor;
21
22/**
23 * A simple executor that maintains a queue and executes one task synchronously every
24 * time {@link #runNext()} is called. This gives us predictable scheduling for the tests to
25 * avoid timeouts waiting for threads to finish.
26 */
27public class MockExecutor implements Executor {
28
29    private final LinkedList<Runnable> mQueue = new LinkedList<Runnable>();
30
31    private boolean mClosed = false;
32
33    public void execute(Runnable task) {
34        if (mClosed) throw new IllegalStateException("closed");
35        mQueue.addLast(task);
36    }
37
38    public void cancelPendingTasks() {
39        mQueue.clear();
40    }
41
42    public void close() {
43        cancelPendingTasks();
44        mClosed = true;
45    }
46
47    public int countPendingTasks() {
48        return mQueue.size();
49    }
50
51    public boolean runNext() {
52        if (mQueue.isEmpty()) {
53            return false;
54        }
55        Runnable command = mQueue.removeFirst();
56        command.run();
57        return true;
58    }
59
60}
61