| /* |
| * Copyright (C) 2008 The Guava Authors |
| * |
| * 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.google.common.util.concurrent; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.Lists; |
| |
| import junit.framework.TestCase; |
| |
| import java.util.List; |
| import java.util.Queue; |
| import java.util.concurrent.CyclicBarrier; |
| import java.util.concurrent.Executor; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.RejectedExecutionException; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| /** |
| * Tests {@link SerializingExecutor}. |
| * |
| * @author JJ Furman |
| */ |
| public class SerializingExecutorTest extends TestCase { |
| private static class FakeExecutor implements Executor { |
| Queue<Runnable> tasks = Lists.newLinkedList(); |
| @Override public void execute(Runnable command) { |
| tasks.add(command); |
| } |
| |
| boolean hasNext() { |
| return !tasks.isEmpty(); |
| } |
| |
| void runNext() { |
| assertTrue("expected at least one task to run", hasNext()); |
| tasks.remove().run(); |
| } |
| |
| } |
| private FakeExecutor fakePool; |
| private SerializingExecutor e; |
| |
| @Override |
| public void setUp() { |
| fakePool = new FakeExecutor(); |
| e = new SerializingExecutor(fakePool); |
| } |
| |
| public void testSerializingNullExecutor_fails() { |
| try { |
| new SerializingExecutor(null); |
| fail("Should have failed with NullPointerException."); |
| } catch (NullPointerException expected) { |
| } |
| } |
| |
| public void testBasics() { |
| final AtomicInteger totalCalls = new AtomicInteger(); |
| Runnable intCounter = new Runnable() { |
| @Override |
| public void run() { |
| totalCalls.incrementAndGet(); |
| } |
| }; |
| |
| assertFalse(fakePool.hasNext()); |
| e.execute(intCounter); |
| assertTrue(fakePool.hasNext()); |
| e.execute(intCounter); |
| assertEquals(0, totalCalls.get()); |
| fakePool.runNext(); // run just 1 sub task... |
| assertEquals(2, totalCalls.get()); |
| assertFalse(fakePool.hasNext()); |
| |
| // Check that execute can be safely repeated |
| e.execute(intCounter); |
| e.execute(intCounter); |
| e.execute(intCounter); |
| assertEquals(2, totalCalls.get()); |
| fakePool.runNext(); |
| assertEquals(5, totalCalls.get()); |
| assertFalse(fakePool.hasNext()); |
| } |
| |
| public void testOrdering() { |
| final List<Integer> callOrder = Lists.newArrayList(); |
| |
| class FakeOp implements Runnable { |
| final int op; |
| |
| FakeOp(int op) { |
| this.op = op; |
| } |
| |
| @Override |
| public void run() { |
| callOrder.add(op); |
| } |
| } |
| |
| e.execute(new FakeOp(0)); |
| e.execute(new FakeOp(1)); |
| e.execute(new FakeOp(2)); |
| fakePool.runNext(); |
| |
| assertEquals(ImmutableList.of(0, 1, 2), callOrder); |
| } |
| |
| public void testExceptions() { |
| |
| final AtomicInteger numCalls = new AtomicInteger(); |
| |
| Runnable runMe = new Runnable() { |
| @Override |
| public void run() { |
| numCalls.incrementAndGet(); |
| throw new RuntimeException("FAKE EXCEPTION!"); |
| } |
| }; |
| |
| e.execute(runMe); |
| e.execute(runMe); |
| fakePool.runNext(); |
| |
| assertEquals(2, numCalls.get()); |
| } |
| |
| public void testDelegateRejection() { |
| final AtomicInteger numCalls = new AtomicInteger(); |
| final AtomicBoolean reject = new AtomicBoolean(true); |
| final SerializingExecutor executor = new SerializingExecutor( |
| new Executor() { |
| @Override public void execute(Runnable r) { |
| if (reject.get()) { |
| throw new RejectedExecutionException(); |
| } |
| r.run(); |
| } |
| }); |
| Runnable task = new Runnable() { |
| @Override |
| public void run() { |
| numCalls.incrementAndGet(); |
| } |
| }; |
| try { |
| executor.execute(task); |
| fail(); |
| } catch (RejectedExecutionException expected) {} |
| assertEquals(0, numCalls.get()); |
| reject.set(false); |
| executor.execute(task); |
| assertEquals(2, numCalls.get()); |
| } |
| |
| public void testTaskThrowsError() throws Exception { |
| class MyError extends Error {} |
| final CyclicBarrier barrier = new CyclicBarrier(2); |
| // we need to make sure the error gets thrown on a different thread. |
| ExecutorService service = Executors.newSingleThreadExecutor(); |
| try { |
| final SerializingExecutor executor = new SerializingExecutor(service); |
| Runnable errorTask = new Runnable() { |
| @Override |
| public void run() { |
| throw new MyError(); |
| } |
| }; |
| Runnable barrierTask = new Runnable() { |
| @Override |
| public void run() { |
| try { |
| barrier.await(); |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| } |
| }; |
| executor.execute(errorTask); |
| service.execute(barrierTask); // submit directly to the service |
| // the barrier task runs after the error task so we know that the error has been observed by |
| // SerializingExecutor by the time the barrier is satified |
| barrier.await(10, TimeUnit.SECONDS); |
| executor.execute(barrierTask); |
| // timeout means the second task wasn't even tried |
| barrier.await(10, TimeUnit.SECONDS); |
| } finally { |
| service.shutdown(); |
| } |
| } |
| } |