| /* |
| * 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 static com.google.common.truth.Truth.assertThat; |
| import static com.google.common.util.concurrent.MoreExecutors.newSequentialExecutor; |
| import static com.google.common.util.concurrent.Uninterruptibles.awaitUninterruptibly; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.Lists; |
| import com.google.common.collect.Queues; |
| import java.util.List; |
| import java.util.Queue; |
| import java.util.concurrent.CountDownLatch; |
| import java.util.concurrent.CyclicBarrier; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.Executor; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.Future; |
| import java.util.concurrent.RejectedExecutionException; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| import java.util.concurrent.atomic.AtomicInteger; |
| import junit.framework.TestCase; |
| |
| /** |
| * Tests {@link SequentialExecutor}. |
| * |
| * @author JJ Furman |
| */ |
| public class SequentialExecutorTest extends TestCase { |
| |
| private static class FakeExecutor implements Executor { |
| Queue<Runnable> tasks = Queues.newArrayDeque(); |
| |
| @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(); |
| } |
| |
| void runAll() { |
| while (hasNext()) { |
| runNext(); |
| } |
| } |
| } |
| |
| private FakeExecutor fakePool; |
| private SequentialExecutor e; |
| |
| @Override |
| public void setUp() { |
| fakePool = new FakeExecutor(); |
| e = new SequentialExecutor(fakePool); |
| } |
| |
| public void testConstructingWithNullExecutor_fails() { |
| try { |
| new SequentialExecutor(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(); |
| // Make sure that no other tasks are scheduled to run while this is running. |
| assertFalse(fakePool.hasNext()); |
| } |
| }; |
| |
| assertFalse(fakePool.hasNext()); |
| e.execute(intCounter); |
| // A task should have been scheduled |
| assertTrue(fakePool.hasNext()); |
| e.execute(intCounter); |
| // Our executor hasn't run any tasks yet. |
| assertEquals(0, totalCalls.get()); |
| fakePool.runAll(); |
| assertEquals(2, totalCalls.get()); |
| // Queue is empty so no runner should be scheduled. |
| assertFalse(fakePool.hasNext()); |
| |
| // Check that execute can be safely repeated |
| e.execute(intCounter); |
| e.execute(intCounter); |
| e.execute(intCounter); |
| // No change yet. |
| assertEquals(2, totalCalls.get()); |
| fakePool.runAll(); |
| 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.runAll(); |
| |
| assertEquals(ImmutableList.of(0, 1, 2), callOrder); |
| } |
| |
| public void testRuntimeException_doesNotStopExecution() { |
| |
| 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.runAll(); |
| |
| assertEquals(2, numCalls.get()); |
| } |
| |
| public void testInterrupt_beforeRunRestoresInterruption() throws Exception { |
| // Run a task on the composed Executor that interrupts its thread (i.e. this thread). |
| fakePool.execute( |
| new Runnable() { |
| @Override |
| public void run() { |
| Thread.currentThread().interrupt(); |
| } |
| }); |
| // Run a task that expects that it is not interrupted while it is running. |
| e.execute( |
| new Runnable() { |
| @Override |
| public void run() { |
| assertThat(Thread.currentThread().isInterrupted()).isFalse(); |
| } |
| }); |
| |
| // Run these together. |
| fakePool.runAll(); |
| |
| // Check that this thread has been marked as interrupted again now that the thread has been |
| // returned by SequentialExecutor. Clear the bit while checking so that the test doesn't hose |
| // JUnit or some other test case. |
| assertThat(Thread.interrupted()).isTrue(); |
| } |
| |
| public void testInterrupt_doesNotInterruptSubsequentTask() throws Exception { |
| // Run a task that interrupts its thread (i.e. this thread). |
| e.execute( |
| new Runnable() { |
| @Override |
| public void run() { |
| Thread.currentThread().interrupt(); |
| } |
| }); |
| // Run a task that expects that it is not interrupted while it is running. |
| e.execute( |
| new Runnable() { |
| @Override |
| public void run() { |
| assertThat(Thread.currentThread().isInterrupted()).isFalse(); |
| } |
| }); |
| |
| // Run those tasks together. |
| fakePool.runAll(); |
| |
| // Check that the interruption of a SequentialExecutor's task is restored to the thread once |
| // it is yielded. Clear the bit while checking so that the test doesn't hose JUnit or some other |
| // test case. |
| assertThat(Thread.interrupted()).isTrue(); |
| } |
| |
| public void testInterrupt_doesNotStopExecution() { |
| |
| final AtomicInteger numCalls = new AtomicInteger(); |
| |
| Runnable runMe = |
| new Runnable() { |
| @Override |
| public void run() { |
| numCalls.incrementAndGet(); |
| } |
| }; |
| |
| Thread.currentThread().interrupt(); |
| |
| e.execute(runMe); |
| e.execute(runMe); |
| fakePool.runAll(); |
| |
| assertEquals(2, numCalls.get()); |
| |
| assertTrue(Thread.interrupted()); |
| } |
| |
| public void testDelegateRejection() { |
| final AtomicInteger numCalls = new AtomicInteger(); |
| final AtomicBoolean reject = new AtomicBoolean(true); |
| final SequentialExecutor executor = |
| new SequentialExecutor( |
| 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(1, 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 SequentialExecutor executor = new SequentialExecutor(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 |
| // SequentialExecutor by the time the barrier is satified |
| barrier.await(1, TimeUnit.SECONDS); |
| executor.execute(barrierTask); |
| // timeout means the second task wasn't even tried |
| barrier.await(1, TimeUnit.SECONDS); |
| } finally { |
| service.shutdown(); |
| } |
| } |
| |
| public void testRejectedExecutionThrownWithMultipleCalls() throws Exception { |
| final CountDownLatch latch = new CountDownLatch(1); |
| final SettableFuture<?> future = SettableFuture.create(); |
| final Executor delegate = |
| new Executor() { |
| @Override |
| public void execute(Runnable task) { |
| if (future.set(null)) { |
| awaitUninterruptibly(latch); |
| } |
| throw new RejectedExecutionException(); |
| } |
| }; |
| final SequentialExecutor executor = new SequentialExecutor(delegate); |
| final ExecutorService blocked = Executors.newCachedThreadPool(); |
| Future<?> first = |
| blocked.submit( |
| new Runnable() { |
| @Override |
| public void run() { |
| executor.execute(Runnables.doNothing()); |
| } |
| }); |
| future.get(10, TimeUnit.SECONDS); |
| try { |
| executor.execute(Runnables.doNothing()); |
| fail(); |
| } catch (RejectedExecutionException expected) { |
| } |
| latch.countDown(); |
| try { |
| first.get(10, TimeUnit.SECONDS); |
| fail(); |
| } catch (ExecutionException expected) { |
| assertThat(expected).hasCauseThat().isInstanceOf(RejectedExecutionException.class); |
| } |
| } |
| |
| public void testToString() { |
| final Runnable[] currentTask = new Runnable[1]; |
| final Executor delegate = |
| new Executor() { |
| @Override |
| public void execute(Runnable task) { |
| currentTask[0] = task; |
| task.run(); |
| currentTask[0] = null; |
| } |
| |
| @Override |
| public String toString() { |
| return "theDelegate"; |
| } |
| }; |
| Executor sequential1 = newSequentialExecutor(delegate); |
| Executor sequential2 = newSequentialExecutor(delegate); |
| assertThat(sequential1.toString()).contains("theDelegate"); |
| assertThat(sequential1.toString()).isNotEqualTo(sequential2.toString()); |
| final String[] whileRunningToString = new String[1]; |
| sequential1.execute( |
| new Runnable() { |
| @Override |
| public void run() { |
| whileRunningToString[0] = "" + currentTask[0]; |
| } |
| |
| @Override |
| public String toString() { |
| return "my runnable's toString"; |
| } |
| }); |
| assertThat(whileRunningToString[0]).contains("my runnable's toString"); |
| } |
| } |