/*
 * Copyright 2006 Takahiro Nakamura.
 *
 * 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 woolpack.utils.concurrent;

import java.util.concurrent.Semaphore;

import junit.framework.TestCase;

public class AcquirableChainImplTest extends TestCase {

	public void testConstructor() {
		try {
			new AcquirableChain((Acquirable[]) null);
			fail();
		} catch (final NullPointerException e) {
		}
	}

	public void testNormal() throws InterruptedException {
		final Semaphore semaphore0 = new Semaphore(1);
		final Semaphore semaphore1 = new Semaphore(1);
		final Acquirable acquirable = new AcquirableChain(new TrySemaphore(
				semaphore0), new TrySemaphore(semaphore1));
		assertTrue(acquirable.acquire());
		assertEquals(0, semaphore0.availablePermits());
		assertEquals(0, semaphore1.availablePermits());

		acquirable.release();
		assertEquals(1, semaphore0.availablePermits());
		assertEquals(1, semaphore1.availablePermits());

		semaphore1.acquire();

		assertFalse(acquirable.acquire());
		assertEquals(1, semaphore0.availablePermits());
		assertEquals(0, semaphore1.availablePermits());

		semaphore1.release();
		semaphore0.acquire();

		assertFalse(acquirable.acquire());
		assertEquals(0, semaphore0.availablePermits());
		assertEquals(1, semaphore1.availablePermits());
	}

	public void testException() throws InterruptedException {
		final Semaphore semaphore0 = new Semaphore(1);
		final Acquirable acquirable = new AcquirableChain(new TrySemaphore(
				semaphore0), AcquirableConstants.INTERRUPTED_EXCEPTION);
		try {
			acquirable.acquire();
			fail();
		} catch (final IllegalStateException e) {
			assertTrue(e.getCause() instanceof InterruptedException);
			assertTrue(Thread.currentThread().isInterrupted());
		}

		assertEquals(1, semaphore0.availablePermits());

		Thread.interrupted();
		semaphore0.acquire();

		assertFalse(acquirable.acquire());
	}
}
