| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.samza.util; |
| |
| import static junit.framework.Assert.*; |
| |
| import org.junit.Before; |
| import org.mockito.Mockito; |
| |
| import org.junit.Test; |
| |
| import java.util.concurrent.TimeUnit; |
| |
| |
| public class TestThrottlingExecutor { |
| private static final long MAX_NANOS = Long.MAX_VALUE; |
| |
| private static final Runnable NO_OP = new Runnable() { |
| @Override |
| public void run() { |
| // Do nothing. |
| } |
| }; |
| |
| private HighResolutionClock clock; |
| private ThrottlingExecutor executor; |
| |
| @Before |
| public void setUp() { |
| clock = Mockito.mock(HighResolutionClock.class); |
| executor = Mockito.spy(new ThrottlingExecutor(MAX_NANOS, clock)); |
| } |
| |
| @Test |
| public void testInitialState() { |
| ThrottlingExecutor throttler = new ThrottlingExecutor(MAX_NANOS); |
| assertEquals(0, throttler.getPendingNanos()); |
| assertEquals(1.0, throttler.getWorkFactor()); |
| } |
| |
| @Test |
| public void testSetWorkRate() { |
| executor.setWorkFactor(1.0); |
| assertEquals(1.0, executor.getWorkFactor()); |
| |
| executor.setWorkFactor(0.5); |
| assertEquals(0.5, executor.getWorkFactor()); |
| |
| executor.setWorkFactor(ThrottlingExecutor.MIN_WORK_FACTOR); |
| assertEquals(ThrottlingExecutor.MIN_WORK_FACTOR, executor.getWorkFactor()); |
| } |
| |
| @Test(expected = IllegalArgumentException.class) |
| public void testLessThan0PercentWorkRate() { |
| new ThrottlingExecutor(MAX_NANOS).setWorkFactor(-0.1); |
| } |
| |
| @Test(expected = IllegalArgumentException.class) |
| public void testGreaterThan100PercentWorkRate() { |
| new ThrottlingExecutor(MAX_NANOS).setWorkFactor(1.1); |
| } |
| |
| @Test |
| public void test100PercentWorkRate() throws InterruptedException { |
| setWorkTime(TimeUnit.MILLISECONDS.toNanos(5)); |
| |
| executor.execute(NO_OP); |
| |
| assertEquals(0L, executor.getPendingNanos()); |
| |
| // At 100% work rate sleep should not be called |
| Mockito.verify(executor, Mockito.never()).sleep(Mockito.anyLong()); |
| } |
| |
| @Test |
| public void test50PercentWorkRate() throws InterruptedException { |
| executor.setWorkFactor(0.5); |
| |
| final long workTimeNanos = TimeUnit.MILLISECONDS.toNanos(5); |
| setWorkTime(workTimeNanos); |
| // Sleep time is same as work time at 50% work rate |
| setActualSleepTime(workTimeNanos); |
| executor.execute(NO_OP); |
| |
| verifySleepTime(workTimeNanos); |
| assertEquals(0L, executor.getPendingNanos()); |
| } |
| |
| @Test |
| public void testMinWorkRate() throws InterruptedException { |
| final double workFactor = ThrottlingExecutor.MIN_WORK_FACTOR; |
| executor.setWorkFactor(workFactor); |
| |
| // The math to work out how much to multiply work time to get expected delay time |
| double workToDelayFactor = (1.0 - workFactor) / workFactor; |
| |
| final long workTimeNanos = TimeUnit.MILLISECONDS.toNanos(5); |
| final long delayTimeNanos = (long) (workToDelayFactor * workTimeNanos); |
| |
| setWorkTime(workTimeNanos); |
| setActualSleepTime(delayTimeNanos); |
| |
| executor.execute(NO_OP); |
| |
| verifySleepTime(delayTimeNanos); |
| assertEquals(0, executor.getPendingNanos()); |
| } |
| |
| @Test |
| public void testSleepOvershoot() throws InterruptedException { |
| executor.setWorkFactor(0.5); |
| |
| final long workTimeNanos = TimeUnit.MILLISECONDS.toNanos(5); |
| final long expectedDelayNanos = workTimeNanos; |
| final long actualDelayTimeNanos = TimeUnit.MILLISECONDS.toNanos(6); |
| |
| setWorkTime(workTimeNanos); |
| setActualSleepTime(actualDelayTimeNanos); |
| |
| executor.execute(NO_OP); |
| |
| verifySleepTime(expectedDelayNanos); |
| assertEquals(expectedDelayNanos - actualDelayTimeNanos, executor.getPendingNanos()); |
| } |
| |
| @Test |
| public void testSleepUndershoot() throws InterruptedException { |
| executor.setWorkFactor(0.5); |
| |
| final long workTimeNanos = TimeUnit.MILLISECONDS.toNanos(5); |
| final long expectedDelayNanos = workTimeNanos; |
| final long actualDelayNanos = TimeUnit.MILLISECONDS.toNanos(4); |
| |
| setWorkTime(workTimeNanos); |
| setActualSleepTime(actualDelayNanos); |
| |
| executor.execute(NO_OP); |
| |
| verifySleepTime(expectedDelayNanos); |
| assertEquals(expectedDelayNanos - actualDelayNanos, executor.getPendingNanos()); |
| } |
| |
| @Test |
| public void testApplyPendingSleepNanos() throws InterruptedException { |
| // This verifies that the executor tries to re-apply pending sleep time on the next execution. |
| executor.setWorkFactor(0.5); |
| |
| final long workTimeNanos = TimeUnit.MILLISECONDS.toNanos(5); |
| final long actualDelayNanos1 = TimeUnit.MILLISECONDS.toNanos(4); |
| final long actualDelayNanos2 = TimeUnit.MILLISECONDS.toNanos(6); |
| |
| // First execution |
| setWorkTime(workTimeNanos); |
| setActualSleepTime(actualDelayNanos1); |
| |
| executor.execute(NO_OP); |
| |
| verifySleepTime(workTimeNanos); |
| assertEquals(workTimeNanos - actualDelayNanos1, executor.getPendingNanos()); |
| |
| |
| // Second execution |
| setWorkTime(workTimeNanos); |
| setActualSleepTime(actualDelayNanos2); |
| |
| executor.execute(NO_OP); |
| |
| verifySleepTime(workTimeNanos); |
| assertEquals(0L, executor.getPendingNanos()); |
| } |
| |
| @Test |
| public void testClampDelayMillis() throws InterruptedException { |
| final long maxDelayMillis = 10; |
| final long maxDelayNanos = TimeUnit.MILLISECONDS.toNanos(maxDelayMillis); |
| |
| executor = Mockito.spy(new ThrottlingExecutor(maxDelayMillis, clock)); |
| executor.setWorkFactor(0.5); |
| |
| // Note work time exceeds maxDelayMillis |
| setWorkTime(TimeUnit.MILLISECONDS.toNanos(100)); |
| setActualSleepTime(maxDelayNanos); |
| |
| executor.execute(NO_OP); |
| |
| verifySleepTime(maxDelayNanos); |
| assertEquals(0L, executor.getPendingNanos()); |
| } |
| |
| @Test |
| public void testDecreaseWorkFactor() { |
| executor.setWorkFactor(0.5); |
| executor.setPendingNanos(5000); |
| |
| executor.setWorkFactor(0.3); |
| assertEquals(5000, executor.getPendingNanos()); |
| } |
| |
| @Test |
| public void testOverflowOfSleepNanos() throws InterruptedException { |
| executor.setWorkFactor(0.5); |
| executor.setPendingNanos(Long.MAX_VALUE); |
| assertEquals(Long.MAX_VALUE, executor.getPendingNanos()); |
| |
| // At a 50% work factor we'd expect work and sleep to match. As they don't, the function will |
| // try to increment the pending sleep nanos, which could (but should not) result in overflow. |
| setWorkTime(5000); |
| setActualSleepTime(Long.MAX_VALUE); |
| |
| executor.execute(NO_OP); |
| |
| // Expect sleep nanos to be clamped to the maximum long value |
| verifySleepTime(Long.MAX_VALUE); |
| } |
| |
| @Test |
| public void testNegativePendingNanos() throws InterruptedException { |
| executor.setWorkFactor(0.5); |
| executor.setPendingNanos(-1000); |
| assertEquals(-1000, executor.getPendingNanos()); |
| |
| // Note: we do not expect the delay time to be used because work time + pending delay is |
| // negative. |
| setWorkTime(500); |
| |
| executor.execute(NO_OP); |
| |
| // Sleep should not be called with negative pending nanos |
| Mockito.verify(executor, Mockito.never()).sleep(Mockito.anyLong()); |
| assertEquals(-1000 + 500, executor.getPendingNanos()); |
| } |
| |
| @Test |
| public void testNegativePendingNanosGoesPositive() throws InterruptedException { |
| executor.setWorkFactor(0.5); |
| long startPendingNanos = -1000; |
| executor.setPendingNanos(startPendingNanos); |
| assertEquals(-1000, executor.getPendingNanos()); |
| |
| setWorkTime(1250); |
| setActualSleepTime(1250 + startPendingNanos); |
| |
| executor.execute(NO_OP); |
| |
| verifySleepTime(1250 + startPendingNanos); |
| assertEquals(0, executor.getPendingNanos()); |
| } |
| |
| private void setWorkTime(long workTimeNanos) { |
| Mockito.when(clock.nanoTime()).thenReturn(0L).thenReturn(workTimeNanos); |
| } |
| |
| private void setActualSleepTime(long actualDelayTimeNanos) throws InterruptedException { |
| Mockito.when(executor.sleep(Mockito.anyLong())).thenAnswer(invocation -> (long) invocation.getArguments()[0] - actualDelayTimeNanos); |
| } |
| |
| private void verifySleepTime(long expectedDelayTimeNanos) throws InterruptedException { |
| Mockito.verify(executor).sleep(expectedDelayTimeNanos); |
| } |
| } |