1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.internal.telephony; 18 19 import static org.junit.Assert.assertTrue; 20 import static org.mockito.ArgumentMatchers.any; 21 import static org.mockito.ArgumentMatchers.anyLong; 22 import static org.mockito.Mockito.doAnswer; 23 import static org.mockito.Mockito.times; 24 import static org.mockito.Mockito.verify; 25 26 import android.os.Handler; 27 import android.os.Looper; 28 import android.support.test.runner.AndroidJUnit4; 29 30 import com.android.internal.telephony.ims.ImsTestBase; 31 32 import org.junit.After; 33 import org.junit.Before; 34 import org.junit.Test; 35 import org.junit.runner.RunWith; 36 import org.mockito.Mock; 37 @RunWith(AndroidJUnit4.class) 38 public class ExponentialBackoffTest extends ImsTestBase { 39 40 private static final int START_DELAY_MS = 10; 41 private static final int MAXIMUM_DELAY_MS = 1000; 42 private static final int MULTIPLIER = 2; 43 44 private ExponentialBackoff mBackoffUnderTest; 45 private Handler mHandler = new Handler(Looper.getMainLooper()); 46 @Mock private Runnable mRunnable; 47 @Mock private ExponentialBackoff.HandlerAdapter mHandlerAdapter; 48 49 @Before 50 public void setUp() throws Exception { 51 super.setUp(); 52 mBackoffUnderTest = new ExponentialBackoff( 53 START_DELAY_MS, MAXIMUM_DELAY_MS, MULTIPLIER, mHandler, mRunnable); 54 mBackoffUnderTest.setHandlerAdapter(mHandlerAdapter); 55 doAnswer(invocation -> mHandler.postDelayed((Runnable) invocation.getArguments()[0], 56 (long) invocation.getArguments()[1]) 57 ).when(mHandlerAdapter).postDelayed(any(Runnable.class), anyLong()); 58 doAnswer(invocation -> { 59 mHandler.removeCallbacks((Runnable) invocation.getArguments()[0]); 60 return null; 61 }).when(mHandlerAdapter).removeCallbacks(any(Runnable.class)); 62 } 63 64 @After 65 public void tearDown() { 66 mBackoffUnderTest.stop(); 67 } 68 69 @Test 70 public void testStartBackoff() { 71 mBackoffUnderTest.start(); 72 long delay = mBackoffUnderTest.getCurrentDelay(); 73 waitForHandlerActionDelayed(mHandler, delay, 2 * delay); 74 75 // The runnable is executed after timeout event occurred. 76 verify(mRunnable).run(); 77 } 78 79 @Test 80 public void testStopBackoff() { 81 mBackoffUnderTest.start(); 82 83 mBackoffUnderTest.stop(); 84 // removeCallbacks is called during start() and stop() 85 verify(mHandlerAdapter, times(2)).removeCallbacks(mRunnable); 86 } 87 88 @Test 89 public void testDelayIncreasedExponentially() { 90 mBackoffUnderTest.start(); 91 // guarantee START_DELAY_MS * 2 ^ i <= MAXIMUM_DELAY_MS 92 for (int i = 1; i < 5; i++) { 93 mBackoffUnderTest.notifyFailed(); 94 long delay = mBackoffUnderTest.getCurrentDelay(); 95 long minDelay = (long) (START_DELAY_MS * Math.pow(MULTIPLIER, i - 1)); 96 long maxDelay = (long) (START_DELAY_MS * Math.pow(MULTIPLIER, i)); 97 assertTrue("delay = " + delay + " minDelay = " + minDelay, delay >= minDelay); 98 assertTrue("delay = " + delay + " maxDelay = " + maxDelay, delay <= maxDelay); 99 } 100 } 101 102 @Test 103 public void testDelayShouldNotExceededTheMaximumLimit() { 104 mBackoffUnderTest.start(); 105 // guarantee START_DELAY_MS * 2 ^ 30 > MAXIMUM_DELAY_MS 106 for (int i = 1; i < 30; i++) { 107 mBackoffUnderTest.notifyFailed(); 108 } 109 long delay = mBackoffUnderTest.getCurrentDelay(); 110 assertTrue( 111 "delay = " + delay + " maximumDelay = " + MAXIMUM_DELAY_MS, 112 delay <= MAXIMUM_DELAY_MS); 113 } 114 } 115
