log4j-core/src/test/java/org/apache/logging/log4j/core/ReusableParameterizedMessageMemoryLeakTest.java

/*
 * 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.logging.log4j.core;

import org.apache.logging.log4j.message.ReusableMessage;
import org.apache.logging.log4j.message.ReusableMessageFactory;
import org.junit.jupiter.api.Test;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import static org.junit.jupiter.api.Assertions.assertTrue;

public class ReusableParameterizedMessageMemoryLeakTest {

    @Test
    public void testParametersAreNotLeaked() throws Exception {
        CountDownLatch latch = new CountDownLatch(1);
        ReusableMessage message = (ReusableMessage) ReusableMessageFactory.INSTANCE.newMessage(
                "foo {}", new ParameterObject("paramValue", latch));
        // Large enough for the parameters, but smaller than the default reusable array size.
        message.swapParameters(new Object[5]);
        try (GarbageCollectionHelper gcHelper = new GarbageCollectionHelper()) {
            gcHelper.run();
            assertTrue(latch.await(30, TimeUnit.SECONDS), "Parameter should have been garbage collected");
        }
    }

    private static final class ParameterObject {
        private final String value;
        private final CountDownLatch latch;
        ParameterObject(String value, CountDownLatch latch) {
            this.value = value;
            this.latch = latch;
        }

        @Override
        public String toString() {
            return value;
        }

        @Override
        protected void finalize() throws Throwable {
            latch.countDown();
            super.finalize();
        }
    }
}