1 /* 2 * Copyright (C) 2018 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 package android.platform.test.microbenchmark; 17 18 import android.os.Bundle; 19 import android.platform.test.composer.Iterate; 20 import android.platform.test.rule.TracePointRule; 21 import androidx.annotation.VisibleForTesting; 22 import androidx.test.InstrumentationRegistry; 23 24 import java.lang.annotation.ElementType; 25 import java.lang.annotation.Retention; 26 import java.lang.annotation.RetentionPolicy; 27 import java.lang.annotation.Target; 28 import java.util.List; 29 30 import org.junit.rules.TestRule; 31 import org.junit.runners.BlockJUnit4ClassRunner; 32 import org.junit.runners.model.InitializationError; 33 import org.junit.runners.model.FrameworkMethod; 34 import org.junit.runners.model.Statement; 35 36 /** 37 * The {@code Microbenchmark} runner allows you to run test methods repeatedly and with {@link 38 * TightMethodRule}s in order to reliably measure a specific test method in isolation. Samples are 39 * soon to follow. 40 */ 41 public class Microbenchmark extends BlockJUnit4ClassRunner { 42 private Bundle mArguments; 43 44 /** 45 * Called reflectively on classes annotated with {@code @RunWith(Microbenchmark.class)}. 46 */ Microbenchmark(Class<?> klass)47 public Microbenchmark(Class<?> klass) throws InitializationError { 48 this(klass, InstrumentationRegistry.getArguments()); 49 } 50 51 /** 52 * Do not call. Called explicitly from tests to provide an arguments. 53 */ 54 @VisibleForTesting Microbenchmark(Class<?> klass, Bundle arguments)55 Microbenchmark(Class<?> klass, Bundle arguments) throws InitializationError { 56 super(klass); 57 mArguments = arguments; 58 } 59 60 /** 61 * Returns a {@link Statement} that invokes {@code method} on {@code test}, surrounded by any 62 * explicit or command-line-supplied {@link TightMethodRule}s. This allows for tighter {@link 63 * TestRule}s that live inside {@link Before} and {@link After} statements. 64 */ 65 @Override methodInvoker(FrameworkMethod method, Object test)66 protected Statement methodInvoker(FrameworkMethod method, Object test) { 67 Statement start = super.methodInvoker(method, test); 68 // Wrap the inner-most test method with trace points. 69 start = getTracePointRule().apply(start, describeChild(method)); 70 // Invoke special @TightMethodRules that wrap @Test methods. 71 List<TestRule> tightMethodRules = 72 getTestClass().getAnnotatedFieldValues(test, TightMethodRule.class, TestRule.class); 73 for (TestRule tightMethodRule : tightMethodRules) { 74 start = tightMethodRule.apply(start, describeChild(method)); 75 } 76 return start; 77 } 78 79 @VisibleForTesting getTracePointRule()80 protected TracePointRule getTracePointRule() { 81 return new TracePointRule(); 82 } 83 84 /** 85 * Returns a list of repeated {@link FrameworkMethod}s to execute. 86 */ 87 @Override getChildren()88 protected List<FrameworkMethod> getChildren() { 89 return new Iterate<FrameworkMethod>().apply(mArguments, super.getChildren()); 90 } 91 92 /** 93 * An annotation for the corresponding tight rules above. These rules are ordered differently 94 * from standard JUnit {@link Rule}s because they live between {@link Before} and {@link After} 95 * methods, instead of wrapping those methods. 96 * 97 * <p>In particular, these serve as a proxy for tight metric collection in microbenchmark-style 98 * tests, where collection is isolated to just the method under test. This is important for when 99 * {@link Before} and {@link After} methods will obscure signal reliability. 100 * 101 * <p> Currently these are only registered from inside a test class as follows, but should soon 102 * be extended for command-line support. 103 * 104 * ``` 105 * @RunWith(Microbenchmark.class) 106 * public class TestClass { 107 * @TightMethodRule 108 * public ExampleRule exampleRule = new ExampleRule(); 109 * 110 * @Test 111 * ... 112 * } 113 * ``` 114 */ 115 @Retention(RetentionPolicy.RUNTIME) 116 @Target({ElementType.FIELD, ElementType.METHOD}) 117 public @interface TightMethodRule { } 118 } 119