org.jvnet.hk2.component.concurrent.WorkManager Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of auto-depends Show documentation
${project.name}
The newest version!
/*
 * 
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 2007-2010 Sun Microsystems, Inc. All rights reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
 * identifying information: "Portions Copyrighted [year]
 * [name of copyright owner]"
 * 
 * Contributor(s):
 * 
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */
package org.jvnet.hk2.component.concurrent;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.FutureTask;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicInteger;

import org.jvnet.hk2.component.ComponentException;

import com.sun.hk2.component.Hk2ThreadContext;

/**
 * Simple helper for managing work sent to a foreign executor service.
 * 
 * 
 * Has similarities to Fork and Join.
 * 
 * 
 * The implementation is designed such that Tasks-1 are sent to the executor
 * service for possibly another thread to handle.  The last task is executed
 * by the caller thread so that all threads are attempted to be fully utilized
 * for processing including the caller's thread.
 * 
 * @author Jeff Trent
 */
public class WorkManager implements Executor {

  private final Executor exec;
  private int tasksToDo;
  private volatile int count;
  private final AtomicInteger workInProgressCount;
  private volatile ArrayList errors;
  
  public WorkManager(Executor exec) {
    this.exec = exec;
    this.workInProgressCount = new AtomicInteger();
  }
  
  public WorkManager(Executor exec, int tasksToDo) {
    this.exec = exec;
    this.workInProgressCount = new AtomicInteger();
    this.tasksToDo = tasksToDo;
  }
  
  public int getWorkInProgressCount() {
    return workInProgressCount.get();
  }
  
  public void awaitCompletion() {
    synchronized (workInProgressCount) {
      if (workInProgressCount.get() > 0) {
        try {
          workInProgressCount.wait();
        } catch (InterruptedException e) {
          throw new ExecutionException(e);
        }
      }
      
      awaitCompletionResults();
    }
  }

  public void awaitCompletion(long timeout, TimeUnit unit) throws TimeoutException {
    synchronized (workInProgressCount) {
      if (workInProgressCount.get() > 0) {
        try {
          workInProgressCount.wait(unit.convert(timeout, TimeUnit.MILLISECONDS));
        } catch (InterruptedException e) {
          throw new ExecutionException(e);
        }
        if (workInProgressCount.get() > 0) {
          throw new TimeoutException();
        }
      }
      
      awaitCompletionResults();
    }
  }
  
  private void awaitCompletionResults() {
    assert(0 == workInProgressCount.get());
    
    if (null != errors && !errors.isEmpty()) {
      ArrayList errors = new ArrayList(this.errors);
      this.errors.clear();
      throw (1 == errors.size() && ComponentException.class.isInstance(errors.get(0)))
          ? (ComponentException)errors.get(0) : new ExecutionException(errors);
    }
  }
  
  protected void completed(Watcher watcher, Exception e) {
//    System.out.print(watcher.toString() + " mark completed on thread " + Thread.currentThread() + "...");
    assert(null != watcher);
    synchronized (workInProgressCount) {
      if (null != e) {
        if (null == errors) {
          errors = new ArrayList();
        }
        errors.add(e);
      }

      int val = workInProgressCount.decrementAndGet();
      if (val <= 0) {
        workInProgressCount.notifyAll();
      }
      
//      System.out.println("done: " + val);
    }
  }
  
  @SuppressWarnings("unchecked")
  public  Collection> submitAll(Collection> tasks) {
    workInProgressCount.addAndGet(tasks.size());

    ArrayList> futures = new ArrayList>();
    for (Callable task : tasks) {
      assert(null != task);

      Watcher watcherTask = new Watcher(task);
      futures.add(watcherTask);
      
      if (++count == tasksToDo) {
        watcherTask.runNow();
      } else {
        exec.execute(watcherTask);
      }
    }
    
    return futures;
  }

  @SuppressWarnings("unchecked")
  public void executeAll(Collection tasks) {
    workInProgressCount.addAndGet(tasks.size());
    
    for (Runnable task : tasks) {
      assert(null != task);

      Watcher watcherTask = new Watcher(task, null);
      
      if (++count == tasksToDo) {
        watcherTask.runNow();
      } else {
        exec.execute(watcherTask);
      }
    }
  }
  
  @SuppressWarnings({ "unused", "unchecked" })
  public  Future submit(Callable task) {
    assert(null != task);
    int work = workInProgressCount.incrementAndGet();

    //    System.out.print("adding more: " + task + "; count=" + work);
    
    Watcher watcherTask = new Watcher(task);
    
    if (++count == tasksToDo) {
      watcherTask.runNow();
    } else {
      exec.execute(watcherTask);
    }
    
    return watcherTask;
  }
  
  @SuppressWarnings("unchecked")
  @Override
  public void execute(Runnable task) {
    assert(null != task);
    workInProgressCount.incrementAndGet();

    Watcher watcherTask = new Watcher(task, null);
    
    if (++count == tasksToDo) {
      watcherTask.runNow();
    } else {
      exec.execute(watcherTask);
    }
  }
  

  private final class Watcher extends FutureTask {
    public Watcher(Callable task) {
      super(task);
    }

    public Watcher(Runnable runnable, V result) {
      super(runnable, result);
    }

    @Override
    public void run() {
      Runnable runnable = new Runnable() {
        @Override
        public void run() {
          runNow();
        }
      };
      Hk2ThreadContext.captureACCandRun(runnable);
    }
    
    private void runNow() {
      try {
        super.run();
        completed(this, null);
      } catch (Exception e){
        setException(e);
        completed(this, e);
      }
    }
  }

  
  @SuppressWarnings("serial")
  public static final class ExecutionException extends ComponentException {
    protected List cause;
    
    public ExecutionException(Throwable t) {
      super(t.getMessage(), t);
      this.cause = Collections.singletonList(t);
    }
    
    public ExecutionException(ExecutionException e) {
      super(e.getMessage(), e.getCause());
      this.cause = Collections.singletonList(e);
    }

    public ExecutionException(List errors) {
      super(errors.get(0).getMessage(), errors.get(0));
      this.cause = errors;
    }

    public  T getCause(Class eClass) {
      for (Throwable e : cause) {
        if (null != e.getCause() && eClass == e.getCause().getClass()) {
          return eClass.cast(e.getCause());
        }
      }
      return null;
    }
    
  }

}