Jason Monk | 5be50f7 | 2017-03-10 10:57:34 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2017 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file |
| 5 | * except in compliance with the License. You may obtain a copy of the License at |
| 6 | * |
| 7 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | * |
| 9 | * Unless required by applicable law or agreed to in writing, software distributed under the |
| 10 | * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| 11 | * KIND, either express or implied. See the License for the specific language governing |
| 12 | * permissions and limitations under the License. |
| 13 | */ |
| 14 | |
| 15 | package android.os; |
| 16 | |
| 17 | import android.util.ArraySet; |
| 18 | |
| 19 | import java.util.concurrent.LinkedBlockingQueue; |
| 20 | |
| 21 | /** |
| 22 | * Blocks a looper from executing any messages, and allows the holder of this object |
| 23 | * to control when and which messages get executed until it is released. |
| 24 | * <p> |
| 25 | * A TestLooperManager should be acquired using |
| 26 | * {@link android.app.Instrumentation#acquireLooperManager}. Until {@link #release()} is called, |
| 27 | * the Looper thread will not execute any messages except when {@link #execute(Message)} is called. |
| 28 | * The test code may use {@link #next()} to acquire messages that have been queued to this |
| 29 | * {@link Looper}/{@link MessageQueue} and then {@link #execute} to run any that desires. |
| 30 | */ |
| 31 | public class TestLooperManager { |
| 32 | |
| 33 | private static final ArraySet<Looper> sHeldLoopers = new ArraySet<>(); |
| 34 | |
| 35 | private final MessageQueue mQueue; |
| 36 | private final Looper mLooper; |
| 37 | private final LinkedBlockingQueue<MessageExecution> mExecuteQueue = new LinkedBlockingQueue<>(); |
| 38 | |
| 39 | private boolean mReleased; |
| 40 | private boolean mLooperBlocked; |
| 41 | |
| 42 | /** |
| 43 | * @hide |
| 44 | */ |
| 45 | public TestLooperManager(Looper looper) { |
| 46 | synchronized (sHeldLoopers) { |
| 47 | if (sHeldLoopers.contains(looper)) { |
| 48 | throw new RuntimeException("TestLooperManager already held for this looper"); |
| 49 | } |
| 50 | sHeldLoopers.add(looper); |
| 51 | } |
| 52 | mLooper = looper; |
| 53 | mQueue = mLooper.getQueue(); |
| 54 | // Post a message that will keep the looper blocked as long as we are dispatching. |
| 55 | new Handler(looper).post(new LooperHolder()); |
| 56 | } |
| 57 | |
| 58 | /** |
| 59 | * Returns the {@link MessageQueue} this object is wrapping. |
| 60 | */ |
Jeff Sharkey | 000ce80 | 2017-04-29 13:13:27 -0600 | [diff] [blame] | 61 | public MessageQueue getMessageQueue() { |
Jason Monk | 5be50f7 | 2017-03-10 10:57:34 -0500 | [diff] [blame] | 62 | checkReleased(); |
| 63 | return mQueue; |
| 64 | } |
| 65 | |
Jeff Sharkey | 000ce80 | 2017-04-29 13:13:27 -0600 | [diff] [blame] | 66 | /** @removed */ |
| 67 | @Deprecated |
| 68 | public MessageQueue getQueue() { |
| 69 | return getMessageQueue(); |
| 70 | } |
| 71 | |
Jason Monk | 5be50f7 | 2017-03-10 10:57:34 -0500 | [diff] [blame] | 72 | /** |
| 73 | * Returns the next message that should be executed by this queue, may block |
| 74 | * if no messages are ready. |
| 75 | * <p> |
| 76 | * Callers should always call {@link #recycle(Message)} on the message when all |
| 77 | * interactions with it have completed. |
| 78 | */ |
| 79 | public Message next() { |
| 80 | // Wait for the looper block to come up, to make sure we don't accidentally get |
| 81 | // the message for the block. |
| 82 | while (!mLooperBlocked) { |
| 83 | synchronized (this) { |
| 84 | try { |
| 85 | wait(); |
| 86 | } catch (InterruptedException e) { |
| 87 | } |
| 88 | } |
| 89 | } |
| 90 | checkReleased(); |
| 91 | return mQueue.next(); |
| 92 | } |
| 93 | |
| 94 | /** |
| 95 | * Releases the looper to continue standard looping and processing of messages, |
| 96 | * no further interactions with TestLooperManager will be allowed after |
| 97 | * release() has been called. |
| 98 | */ |
| 99 | public void release() { |
| 100 | synchronized (sHeldLoopers) { |
| 101 | sHeldLoopers.remove(mLooper); |
| 102 | } |
| 103 | checkReleased(); |
| 104 | mReleased = true; |
| 105 | mExecuteQueue.add(new MessageExecution()); |
| 106 | } |
| 107 | |
| 108 | /** |
| 109 | * Executes the given message on the Looper thread this wrapper is |
| 110 | * attached to. |
| 111 | * <p> |
| 112 | * Execution will happen on the Looper's thread (whether it is the current thread |
| 113 | * or not), but all RuntimeExceptions encountered while executing the message will |
| 114 | * be thrown on the calling thread. |
| 115 | */ |
| 116 | public void execute(Message message) { |
| 117 | checkReleased(); |
| 118 | if (Looper.myLooper() == mLooper) { |
| 119 | // This is being called from the thread it should be executed on, we can just dispatch. |
| 120 | message.target.dispatchMessage(message); |
| 121 | } else { |
| 122 | MessageExecution execution = new MessageExecution(); |
| 123 | execution.m = message; |
| 124 | synchronized (execution) { |
| 125 | mExecuteQueue.add(execution); |
| 126 | // Wait for the message to be executed. |
| 127 | try { |
| 128 | execution.wait(); |
| 129 | } catch (InterruptedException e) { |
| 130 | } |
| 131 | if (execution.response != null) { |
| 132 | throw new RuntimeException(execution.response); |
| 133 | } |
| 134 | } |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | /** |
| 139 | * Called to indicate that a Message returned by {@link #next()} has been parsed |
| 140 | * and should be recycled. |
| 141 | */ |
| 142 | public void recycle(Message msg) { |
| 143 | checkReleased(); |
| 144 | msg.recycleUnchecked(); |
| 145 | } |
| 146 | |
| 147 | /** |
| 148 | * Returns true if there are any queued messages that match the parameters. |
| 149 | * |
| 150 | * @param h the value of {@link Message#getTarget()} |
| 151 | * @param what the value of {@link Message#what} |
| 152 | * @param object the value of {@link Message#obj}, null for any |
| 153 | */ |
| 154 | public boolean hasMessages(Handler h, Object object, int what) { |
| 155 | checkReleased(); |
| 156 | return mQueue.hasMessages(h, what, object); |
| 157 | } |
| 158 | |
| 159 | /** |
| 160 | * Returns true if there are any queued messages that match the parameters. |
| 161 | * |
| 162 | * @param h the value of {@link Message#getTarget()} |
| 163 | * @param r the value of {@link Message#getCallback()} |
| 164 | * @param object the value of {@link Message#obj}, null for any |
| 165 | */ |
| 166 | public boolean hasMessages(Handler h, Object object, Runnable r) { |
| 167 | checkReleased(); |
| 168 | return mQueue.hasMessages(h, r, object); |
| 169 | } |
| 170 | |
| 171 | private void checkReleased() { |
| 172 | if (mReleased) { |
| 173 | throw new RuntimeException("release() has already be called"); |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | private class LooperHolder implements Runnable { |
| 178 | @Override |
| 179 | public void run() { |
| 180 | synchronized (TestLooperManager.this) { |
| 181 | mLooperBlocked = true; |
| 182 | TestLooperManager.this.notify(); |
| 183 | } |
| 184 | while (!mReleased) { |
| 185 | try { |
| 186 | final MessageExecution take = mExecuteQueue.take(); |
| 187 | if (take.m != null) { |
| 188 | processMessage(take); |
| 189 | } |
| 190 | } catch (InterruptedException e) { |
| 191 | } |
| 192 | } |
| 193 | synchronized (TestLooperManager.this) { |
| 194 | mLooperBlocked = false; |
| 195 | } |
| 196 | } |
| 197 | |
| 198 | private void processMessage(MessageExecution mex) { |
| 199 | synchronized (mex) { |
| 200 | try { |
| 201 | mex.m.target.dispatchMessage(mex.m); |
| 202 | mex.response = null; |
| 203 | } catch (Throwable t) { |
| 204 | mex.response = t; |
| 205 | } |
| 206 | mex.notifyAll(); |
| 207 | } |
| 208 | } |
| 209 | } |
| 210 | |
| 211 | private static class MessageExecution { |
| 212 | private Message m; |
| 213 | private Throwable response; |
| 214 | } |
| 215 | } |