/*
* 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.tomcat.util.collections;
import org.junit.Assert;
import org.junit.Test;
public class TestSynchronizedStack {
@Test
public void testPopEmpty() {
SynchronizedStack<Object> stack = new SynchronizedStack<>();
Assert.assertNull(stack.pop());
}
@Test
public void testPushPopOrder() {
SynchronizedStack<Object> stack = new SynchronizedStack<>();
Object o1 = new Object();
Object o2 = new Object();
Object o3 = new Object();
Object o4 = new Object();
stack.push(o1);
stack.push(o2);
stack.push(o3);
stack.push(o4);
Assert.assertSame(stack.pop(), o4);
Assert.assertSame(stack.pop(), o3);
Assert.assertSame(stack.pop(), o2);
Assert.assertSame(stack.pop(), o1);
Assert.assertNull(stack.pop());
}
@Test
public void testExpandPushPopOrder() {
SynchronizedStack<Object> stack = new SynchronizedStack<>();
Object o1 = new Object();
Object o2 = new Object();
Object o3 = new Object();
Object o4 = new Object();
for (int i = 0; i < 300; i++) {
stack.push(o1);
stack.push(o2);
stack.push(o3);
stack.push(o4);
}
for (int i = 0; i < 300; i++) {
Assert.assertSame(stack.pop(), o4);
Assert.assertSame(stack.pop(), o3);
Assert.assertSame(stack.pop(), o2);
Assert.assertSame(stack.pop(), o1);
}
Assert.assertNull(stack.pop());
}
@Test
public void testLimit() {
SynchronizedStack<Object> stack = new SynchronizedStack<>(2,2);
Object o1 = new Object();
Object o2 = new Object();
Object o3 = new Object();
Object o4 = new Object();
stack.push(o1);
stack.push(o2);
stack.push(o3);
stack.push(o4);
Assert.assertSame(stack.pop(), o2);
Assert.assertSame(stack.pop(), o1);
Assert.assertNull(stack.pop());
}
@Test
public void testLimitExpand() {
SynchronizedStack<Object> stack = new SynchronizedStack<>(1,3);
Object o1 = new Object();
Object o2 = new Object();
Object o3 = new Object();
Object o4 = new Object();
stack.push(o1);
stack.push(o2);
stack.push(o3);
stack.push(o4);
Assert.assertSame(stack.pop(), o3);
Assert.assertSame(stack.pop(), o2);
Assert.assertSame(stack.pop(), o1);
Assert.assertNull(stack.pop());
}
}