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TypeCachingMockBytecodeGeneratorTest.java
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TypeCachingMockBytecodeGeneratorTest.java
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/*
* Copyright (c) 2017 Mockito contributors
* This program is made available under the terms of the MIT License.
*/
package org.mockito.internal.creation.bytebuddy;
import static org.assertj.core.api.Assertions.assertThat;
import static org.mockito.internal.creation.bytebuddy.MockFeatures.withMockFeatures;
import static org.mockitoutil.ClassLoaders.inMemoryClassLoader;
import static org.mockitoutil.SimpleClassGenerator.makeMarkerInterface;
import java.lang.ref.PhantomReference;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.IdentityHashMap;
import java.util.Set;
import java.util.WeakHashMap;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.Phaser;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.function.Function;
import org.junit.Before;
import org.junit.Test;
import org.mockito.Answers;
import org.mockito.mock.SerializableMode;
import org.mockitoutil.VmArgAssumptions;
public class TypeCachingMockBytecodeGeneratorTest {
@Before
public void ensure_disable_gc_is_activated() throws Exception {
VmArgAssumptions.assumeVmArgNotPresent("-XX:+DisableExplicitGC");
}
@Test
public void ensure_cache_is_cleared_if_no_reference_to_classloader_and_classes()
throws Exception {
// given
ClassLoader classloader_with_life_shorter_than_cache =
inMemoryClassLoader()
.withClassDefinition("foo.Bar", makeMarkerInterface("foo.Bar"))
.build();
TypeCachingBytecodeGenerator cachingMockBytecodeGenerator =
new TypeCachingBytecodeGenerator(new SubclassBytecodeGenerator(), true);
Class<?> the_mock_type =
cachingMockBytecodeGenerator.mockClass(
withMockFeatures(
classloader_with_life_shorter_than_cache.loadClass("foo.Bar"),
Collections.<Class<?>>emptySet(),
SerializableMode.NONE,
false,
Answers.RETURNS_DEFAULTS));
ReferenceQueue<Object> referenceQueue = new ReferenceQueue<Object>();
Reference<Object> typeReference =
new PhantomReference<Object>(the_mock_type, referenceQueue);
// when
classloader_with_life_shorter_than_cache = is_no_more_referenced();
the_mock_type = is_no_more_referenced();
System.gc();
ensure_gc_happened();
// then
assertThat(referenceQueue.poll()).isEqualTo(typeReference);
}
@Test
public void ensure_cache_returns_same_instance() throws Exception {
// given
ClassLoader classloader_with_life_shorter_than_cache =
inMemoryClassLoader()
.withClassDefinition("foo.Bar", makeMarkerInterface("foo.Bar"))
.build();
TypeCachingBytecodeGenerator cachingMockBytecodeGenerator =
new TypeCachingBytecodeGenerator(new SubclassBytecodeGenerator(), true);
Class<?> the_mock_type =
cachingMockBytecodeGenerator.mockClass(
withMockFeatures(
classloader_with_life_shorter_than_cache.loadClass("foo.Bar"),
Collections.<Class<?>>emptySet(),
SerializableMode.NONE,
false,
Answers.RETURNS_DEFAULTS));
Class<?> other_mock_type =
cachingMockBytecodeGenerator.mockClass(
withMockFeatures(
classloader_with_life_shorter_than_cache.loadClass("foo.Bar"),
Collections.<Class<?>>emptySet(),
SerializableMode.NONE,
false,
Answers.RETURNS_DEFAULTS));
assertThat(other_mock_type).isSameAs(the_mock_type);
ReferenceQueue<Object> referenceQueue = new ReferenceQueue<Object>();
Reference<Object> typeReference =
new PhantomReference<Object>(the_mock_type, referenceQueue);
// when
classloader_with_life_shorter_than_cache = is_no_more_referenced();
the_mock_type = is_no_more_referenced();
other_mock_type = is_no_more_referenced();
System.gc();
ensure_gc_happened();
// then
assertThat(referenceQueue.poll()).isEqualTo(typeReference);
}
@Test
public void ensure_cache_returns_different_instance_serializableMode() throws Exception {
// given
ClassLoader classloader_with_life_shorter_than_cache =
inMemoryClassLoader()
.withClassDefinition("foo.Bar", makeMarkerInterface("foo.Bar"))
.build();
TypeCachingBytecodeGenerator cachingMockBytecodeGenerator =
new TypeCachingBytecodeGenerator(new SubclassBytecodeGenerator(), true);
Class<?> the_mock_type =
cachingMockBytecodeGenerator.mockClass(
withMockFeatures(
classloader_with_life_shorter_than_cache.loadClass("foo.Bar"),
Collections.<Class<?>>emptySet(),
SerializableMode.NONE,
false,
Answers.RETURNS_DEFAULTS));
Class<?> other_mock_type =
cachingMockBytecodeGenerator.mockClass(
withMockFeatures(
classloader_with_life_shorter_than_cache.loadClass("foo.Bar"),
Collections.<Class<?>>emptySet(),
SerializableMode.BASIC,
false,
Answers.RETURNS_DEFAULTS));
assertThat(other_mock_type).isNotSameAs(the_mock_type);
}
@Test
public void ensure_cache_returns_same_instance_defaultAnswer() throws Exception {
// given
ClassLoader classloader_with_life_shorter_than_cache =
inMemoryClassLoader()
.withClassDefinition("foo.Bar", makeMarkerInterface("foo.Bar"))
.build();
TypeCachingBytecodeGenerator cachingMockBytecodeGenerator =
new TypeCachingBytecodeGenerator(new SubclassBytecodeGenerator(), true);
Answers[] answers = Answers.values();
Set<Class<?>> classes = Collections.newSetFromMap(new IdentityHashMap<>());
classes.add(
cachingMockBytecodeGenerator.mockClass(
withMockFeatures(
classloader_with_life_shorter_than_cache.loadClass("foo.Bar"),
Collections.<Class<?>>emptySet(),
SerializableMode.NONE,
false,
null)));
for (Answers answer : answers) {
Class<?> klass =
cachingMockBytecodeGenerator.mockClass(
withMockFeatures(
classloader_with_life_shorter_than_cache.loadClass("foo.Bar"),
Collections.<Class<?>>emptySet(),
SerializableMode.NONE,
false,
answer));
assertThat(classes.add(klass)).isFalse();
}
assertThat(classes).hasSize(1);
}
@Test
public void
validate_simple_code_idea_where_weakhashmap_with_classloader_as_key_get_GCed_when_no_more_references()
throws Exception {
// given
WeakHashMap<ClassLoader, Object> cache = new WeakHashMap<ClassLoader, Object>();
ClassLoader short_lived_classloader =
inMemoryClassLoader()
.withClassDefinition("foo.Bar", makeMarkerInterface("foo.Bar"))
.build();
cache.put(
short_lived_classloader,
new HoldingAReference(
new WeakReference<Class<?>>(short_lived_classloader.loadClass("foo.Bar"))));
assertThat(cache).hasSize(1);
// when
short_lived_classloader = is_no_more_referenced();
System.gc();
ensure_gc_happened();
// then
assertThat(cache).isEmpty();
}
@Test
public void cacheLockingStressTest_same_hashcode_different_interface()
throws InterruptedException, TimeoutException {
Class<?>[] classes = cacheLockingInMemClassLoaderClasses();
Class<?> ifA = classes[0];
Class<?> ifB = classes[1];
var featA = newMockFeatures(ifA, ifB);
var featB = newMockFeatures(ifB, ifA);
cacheLockingStressTestImpl(featA, featB);
}
@Test
public void cacheLockingStressTest_same_hashcode_same_interface()
throws InterruptedException, TimeoutException {
Class<?>[] classes = cacheLockingInMemClassLoaderClasses();
Class<?> ifA = classes[0];
var featA = newMockFeatures(ifA);
cacheLockingStressTestImpl(featA, featA);
}
@Test
public void cacheLockingStressTest_different_hashcode()
throws InterruptedException, TimeoutException {
Class<?>[] classes = cacheLockingInMemClassLoaderClasses();
Class<?> ifA = classes[0];
Class<?> ifB = classes[1];
Class<?> ifC = classes[2];
var featA = newMockFeatures(ifA, ifB);
var featB = newMockFeatures(ifB, ifC);
cacheLockingStressTestImpl(featA, featB);
}
@Test
public void cacheLockingStressTest_unrelated_classes()
throws InterruptedException, TimeoutException {
Class<?>[] classes = cacheLockingInMemClassLoaderClasses();
Class<?> ifA = classes[0];
Class<?> ifB = classes[1];
var featA = newMockFeatures(ifA);
var featB = newMockFeatures(ifB);
cacheLockingStressTestImpl(featA, featB);
}
private void cacheLockingStressTestImpl(MockFeatures<?> featA, MockFeatures<?> featB)
throws InterruptedException, TimeoutException {
int iterations = 10_000;
TypeCachingBytecodeGenerator bytecodeGenerator =
new TypeCachingBytecodeGenerator(new SubclassBytecodeGenerator(), true);
Phaser phaser = new Phaser(4);
Function<Runnable, CompletableFuture<Void>> runCode =
code ->
CompletableFuture.runAsync(
() -> {
phaser.arriveAndAwaitAdvance();
try {
for (int i = 0; i < iterations; i++) {
code.run();
}
} finally {
phaser.arrive();
}
});
var mockFeatAFuture =
runCode.apply(
() -> {
Class<?> mockClass = bytecodeGenerator.mockClass(featA);
assertValidMockClass(featA, mockClass);
});
var mockFeatBFuture =
runCode.apply(
() -> {
Class<?> mockClass = bytecodeGenerator.mockClass(featB);
assertValidMockClass(featB, mockClass);
});
var cacheFuture = runCode.apply(bytecodeGenerator::clearAllCaches);
// Start test
phaser.arriveAndAwaitAdvance();
// Wait for test to end
int phase = phaser.arrive();
try {
phaser.awaitAdvanceInterruptibly(phase, 30, TimeUnit.SECONDS);
} finally {
// Collect exceptions from the futures, to make issues visible.
mockFeatAFuture.getNow(null);
mockFeatBFuture.getNow(null);
cacheFuture.getNow(null);
}
}
private static <T> MockFeatures<T> newMockFeatures(
Class<T> mockedType, Class<?>... interfaces) {
return MockFeatures.withMockFeatures(
mockedType,
new HashSet<>(Arrays.asList(interfaces)),
SerializableMode.NONE,
false,
null);
}
private static Class<?>[] cacheLockingInMemClassLoaderClasses() {
ClassLoader inMemClassLoader =
inMemoryClassLoader()
.withClassDefinition("foo.IfA", makeMarkerInterface("foo.IfA"))
.withClassDefinition("foo.IfB", makeMarkerInterface("foo.IfB"))
.withClassDefinition("foo.IfC", makeMarkerInterface("foo.IfC"))
.build();
try {
return new Class[] {
inMemClassLoader.loadClass("foo.IfA"),
inMemClassLoader.loadClass("foo.IfB"),
inMemClassLoader.loadClass("foo.IfC")
};
} catch (ClassNotFoundException e) {
throw new IllegalStateException(e);
}
}
private void assertValidMockClass(MockFeatures<?> mockFeature, Class<?> mockClass) {
assertThat(mockClass).isAssignableTo(mockFeature.mockedType);
for (Class<?> anInterface : mockFeature.interfaces) {
assertThat(mockClass).isAssignableTo(anInterface);
}
}
static class HoldingAReference {
final WeakReference<Class<?>> a;
HoldingAReference(WeakReference<Class<?>> a) {
this.a = a;
}
}
private static <T> T is_no_more_referenced() {
return null;
}
private static void ensure_gc_happened() throws InterruptedException {
// wait in order to make sure the GC happened
Thread.sleep(500);
}
}