/*******************************************************************************

 * Copyright (c) 2012 IBM Corporation and others.

 * All rights reserved. This program and the accompanying materials

 * are made available under the terms of the Eclipse Public License v1.0

 * which accompanies this distribution, and is available at

 * http://www.eclipse.org/legal/epl-v10.html

 * 

 * Contributors:

 * 	ivan.motsch@bsiag.com - initial example

 *     IBM Corporation - converted to JUnit test

 *******************************************************************************/

package org.eclipse.core.tests.runtime.jobs;

import java.util.concurrent.Semaphore;

import org.eclipse.core.runtime.*;

import org.eclipse.core.runtime.jobs.Job;

/**

 * Tests that scheduling multiple jobs with a delay and then blocking all active

 * worker threads doesn't cause job manager to starve. This is a regression

 * test for a situation where all worker threads were blocked and no workers

 * were available to process sleeping jobs awaiting execution. For details see:

 * https://bugs.eclipse.org/bugs/show_bug.cgi?id=366170

 */

public class Bug_366170 extends AbstractJobManagerTest {

	private Semaphore m_jobBStopHint = new Semaphore(1);

	public void testBug() throws Exception {

		System.out.println("--- Running the examle ---");

		m_jobBStopHint.acquire();

		scheduleJobA(200);

		scheduleJobC(300);

		Thread.sleep(2000L);

		//lock should now be free if C is finished

		assertTrue("Failed: Job C was not run", m_jobBStopHint.tryAcquire());

	}

	private void scheduleJobA(long delay) throws Exception {

		Job job = new Job("A") {

			@Override

			public boolean shouldSchedule() {

				System.out.println("schedule " + getName());

				return true;

			}

			protected IStatus run(IProgressMonitor monitor) {

				System.out.println("begin " + getName());

				try {

					scheduleJobB(0).join();

				} catch (Throwable t) {

					t.printStackTrace();

				}

				System.out.println("end   " + getName());

				return Status.OK_STATUS;

			}

		};

		job.setSystem(true);

		job.schedule(delay);

	}

	private Job scheduleJobB(long delay) throws Exception {

		Job job = new Job("B") {

			@Override

			public boolean shouldSchedule() {

				System.out.println("schedule " + getName());

				return true;

			}

			@Override

			protected IStatus run(IProgressMonitor monitor) {

				System.out.println("begin " + getName());

				try {

					m_jobBStopHint.acquire();

				} catch (InterruptedException e) {

					e.printStackTrace();

				}

				m_jobBStopHint.release();

				System.out.println("end   " + getName());

				return Status.OK_STATUS;

			}

		};

		job.setSystem(true);

		job.schedule(delay);

		return job;

	}

	private void scheduleJobC(long delay) throws Exception {

		Job job = new Job("C") {

			@Override

			public boolean shouldSchedule() {

				System.out.println("schedule " + getName());

				return true;

			}

			@Override

			protected IStatus run(IProgressMonitor monitor) {

				System.out.println("begin " + getName());

				m_jobBStopHint.release();

				System.out.println("end   " + getName());

				return Status.OK_STATUS;

			}

		};

		job.setSystem(true);

		job.schedule(delay);

	}

}