| /* |
| * 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.ArgumentCaptor; |
| import org.mockito.Mockito; |
| |
| import org.junit.Test; |
| |
| import java.util.concurrent.ScheduledExecutorService; |
| import java.util.concurrent.TimeUnit; |
| |
| public class TestThrottlingScheduler { |
| 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 ScheduledExecutorService scheduledExecutorService; |
| private ThrottlingScheduler throttler; |
| |
| @Before |
| public void setUp() { |
| clock = Mockito.mock(HighResolutionClock.class); |
| scheduledExecutorService = Mockito.mock(ScheduledExecutorService.class); |
| throttler = new ThrottlingScheduler(MAX_NANOS, scheduledExecutorService, clock); |
| } |
| |
| @Test |
| public void testInitialState() { |
| ThrottlingExecutor throttler = new ThrottlingExecutor(MAX_NANOS); |
| assertEquals(0, throttler.getPendingNanos()); |
| assertEquals(1.0, throttler.getWorkFactor()); |
| } |
| |
| @Test |
| public void testSetWorkRate() { |
| throttler.setWorkFactor(1.0); |
| assertEquals(1.0, throttler.getWorkFactor()); |
| |
| throttler.setWorkFactor(0.5); |
| assertEquals(0.5, throttler.getWorkFactor()); |
| |
| throttler.setWorkFactor(Throttleable.MIN_WORK_FACTOR); |
| assertEquals(Throttleable.MIN_WORK_FACTOR, throttler.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 { |
| throttler.schedule(NO_OP, 1000); |
| |
| assertEquals(0L, throttler.getPendingNanos()); |
| |
| // At 100% work rate schedule should not be called |
| Mockito.verify(scheduledExecutorService, Mockito.never()) |
| .schedule(Mockito.any(Runnable.class), Mockito.anyLong(), Mockito.any(TimeUnit.class)); |
| } |
| |
| @Test |
| public void test50PercentWorkRate() throws InterruptedException { |
| throttler.setWorkFactor(0.5); |
| |
| final long workTimeNanos = TimeUnit.MILLISECONDS.toNanos(5); |
| setActualDelay(workTimeNanos); |
| |
| throttler.schedule(NO_OP, workTimeNanos); |
| |
| // Delay time is same as work time at 50% work rate |
| verifyRequestedDelay(workTimeNanos); |
| assertEquals(0L, throttler.getPendingNanos()); |
| } |
| |
| @Test |
| public void testMinWorkRate() throws InterruptedException { |
| final double workFactor = Throttleable.MIN_WORK_FACTOR; |
| throttler.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); |
| |
| setActualDelay(delayTimeNanos); |
| throttler.schedule(NO_OP, workTimeNanos); |
| |
| verifyRequestedDelay(delayTimeNanos); |
| assertEquals(0, throttler.getPendingNanos()); |
| } |
| |
| @Test |
| public void testDelayOvershoot() throws InterruptedException { |
| throttler.setWorkFactor(0.5); |
| |
| final long workTimeNanos = TimeUnit.MILLISECONDS.toNanos(5); |
| final long expectedDelayNanos = workTimeNanos; |
| final long actualDelayNanos = TimeUnit.MILLISECONDS.toNanos(6); |
| |
| setActualDelay(actualDelayNanos); |
| |
| throttler.schedule(NO_OP, workTimeNanos); |
| |
| verifyRequestedDelay(expectedDelayNanos); |
| assertEquals(expectedDelayNanos - actualDelayNanos, throttler.getPendingNanos()); |
| } |
| |
| @Test |
| public void testDelayUndershoot() throws InterruptedException { |
| throttler.setWorkFactor(0.5); |
| |
| final long workTimeNanos = TimeUnit.MILLISECONDS.toNanos(5); |
| final long expectedDelayNanos = workTimeNanos; |
| final long actualDelayNanos = TimeUnit.MILLISECONDS.toNanos(4); |
| |
| setActualDelay(actualDelayNanos); |
| |
| throttler.schedule(NO_OP, workTimeNanos); |
| |
| verifyRequestedDelay(expectedDelayNanos); |
| assertEquals(expectedDelayNanos - actualDelayNanos, throttler.getPendingNanos()); |
| } |
| |
| @Test |
| public void testClampDelayMillis() throws InterruptedException { |
| final long maxDelayMillis = 10; |
| final long maxDelayNanos = TimeUnit.MILLISECONDS.toNanos(maxDelayMillis); |
| |
| ThrottlingScheduler throttler = new ThrottlingScheduler(maxDelayMillis, scheduledExecutorService, clock); |
| throttler.setWorkFactor(0.5); |
| |
| setActualDelay(maxDelayNanos); |
| |
| // Note work time exceeds maxDelayMillis |
| throttler.schedule(NO_OP, TimeUnit.MILLISECONDS.toNanos(100)); |
| |
| verifyRequestedDelay(maxDelayNanos); |
| assertEquals(0L, throttler.getPendingNanos()); |
| } |
| |
| @Test |
| public void testDecreaseWorkFactor() { |
| throttler.setWorkFactor(0.5); |
| throttler.setPendingNanos(5000); |
| |
| throttler.setWorkFactor(0.3); |
| assertEquals(5000, throttler.getPendingNanos()); |
| } |
| |
| @Test |
| public void testOverflowOfDelayNanos() throws InterruptedException { |
| throttler.setWorkFactor(0.5); |
| throttler.setPendingNanos(Long.MAX_VALUE); |
| assertEquals(Long.MAX_VALUE, throttler.getPendingNanos()); |
| |
| // At a 50% work factor we'd expect work and delay to match. The function will try |
| // to increment the pending delay nanos, which could (but should not) result in overflow. |
| long workDurationNs = 5000; |
| setActualDelay(workDurationNs); |
| throttler.schedule(NO_OP, workDurationNs); |
| verifyRequestedDelay(workDurationNs); |
| |
| // Expect delay nanos to be clamped during accumulation, and decreased by expected delay at the end. |
| assertEquals(Long.MAX_VALUE - workDurationNs, throttler.getPendingNanos()); |
| } |
| |
| @Test |
| public void testNegativePendingNanos() throws InterruptedException { |
| throttler.setWorkFactor(0.5); |
| throttler.setPendingNanos(-1000); |
| assertEquals(-1000, throttler.getPendingNanos()); |
| |
| // Note: we do not expect the delay time to be used because work time + pending delay is |
| // negative. |
| throttler.schedule(NO_OP, 500); |
| |
| // Should not be delayed with negative pending nanos |
| Mockito.verify(scheduledExecutorService, Mockito.never()) |
| .schedule(Mockito.any(Runnable.class), Mockito.anyLong(), Mockito.any(TimeUnit.class)); |
| assertEquals(-1000 + 500, throttler.getPendingNanos()); |
| } |
| |
| @Test |
| public void testNegativePendingNanosGoesPositive() throws InterruptedException { |
| throttler.setWorkFactor(0.5); |
| long startPendingNanos = -1000; |
| throttler.setPendingNanos(startPendingNanos); |
| assertEquals(-1000, throttler.getPendingNanos()); |
| |
| setActualDelay(1250); |
| |
| // We request a delay greater than the starting pending delay. |
| throttler.schedule(NO_OP, 1250); |
| |
| verifyRequestedDelay(1250); |
| |
| // Final pending delay should equal initial pending delay since we delay |
| // for the exact requested amount. |
| assertEquals(startPendingNanos, throttler.getPendingNanos()); |
| } |
| |
| private void setActualDelay(long actualDelayNs) { |
| Mockito.when(clock.nanoTime()).thenReturn(0L).thenReturn(actualDelayNs); |
| } |
| |
| private void verifyRequestedDelay(long expectedDelayTimeNanos) throws InterruptedException { |
| ArgumentCaptor<Runnable> runnableCaptor = ArgumentCaptor.forClass(Runnable.class); |
| Mockito.verify(scheduledExecutorService) |
| .schedule(runnableCaptor.capture(), Mockito.eq(expectedDelayTimeNanos), Mockito.eq(TimeUnit.NANOSECONDS)); |
| runnableCaptor.getValue().run(); |
| } |
| } |