/*
* Licensed 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.jctools.queues.atomic;
import org.junit.Test;
import static org.hamcrest.Matchers.hasSize;
import static org.hamcrest.Matchers.not;
import static org.hamcrest.Matchers.sameInstance;
import static org.jctools.queues.matchers.Matchers.emptyAndZeroSize;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.assertTrue;
public class AtomicSpscArrayQueueTest {
@Test
public void shouldWorkAfterWrap(){
// Arrange
final SpscAtomicArrayQueue<Object> q = new SpscAtomicArrayQueue<Object>(1024);
// starting point for empty queue at max long, next offer will wrap the producerIndex
q.consumerIndex.set(Long.MAX_VALUE);
q.producerIndex.set(Long.MAX_VALUE);
q.producerLookAhead = Long.MAX_VALUE;
// valid starting point
assertThat(q, emptyAndZeroSize());
// Act
// assert offer is successful
final Object e = new Object();
assertTrue(q.offer(e));
// size is computed correctly after wrap
assertThat(q, not(emptyAndZeroSize()));
assertThat(q, hasSize(1));
// now consumer index wraps
final Object poll = q.poll();
assertThat(poll, sameInstance(e));
assertThat(q, emptyAndZeroSize());
// let's go again
assertTrue(q.offer(e));
assertThat(q, not(emptyAndZeroSize()));
final Object poll2 = q.poll();
assertThat(poll2, sameInstance(e));
assertThat(q, emptyAndZeroSize());
}
}