SimpleCommandQueue.java

package jetbrains.mps.vcs.changesmanager;

/*Generated by MPS */

import org.apache.log4j.Logger;
import org.apache.log4j.LogManager;
import java.util.Queue;
import java.util.LinkedList;
import org.jetbrains.annotations.NotNull;
import org.apache.log4j.Level;

public class SimpleCommandQueue {
  private static final Logger LOG = LogManager.getLogger(SimpleCommandQueue.class);
  private Thread myThread;
  private boolean myDisposed = false;
  private boolean myHadExceptions = false;
  private final Queue<Runnable> myQueue = new LinkedList<Runnable>();
  public SimpleCommandQueue(@NotNull String threadName) {
    myThread = new SimpleCommandQueue.MyExecutorThread(threadName);
    myThread.start();
  }
  public void runTask(@NotNull Runnable task) {
    if (Thread.currentThread() == myThread) {
      task.run();
    } else {
      addTask(task);
    }
  }
  public void addTask(@NotNull Runnable task) {
    synchronized (myQueue) {
      myQueue.add(task);
      myQueue.notify();
    }
  }
  public void dispose() {
    myDisposed = true;
    myThread.interrupt();
  }
  public void assertIsCommandThread() {
    assert Thread.currentThread() == myThread;
  }
  public void assertSoftlyIsCommandThread() {
    if (Thread.currentThread() != myThread) {
      if (LOG.isEnabledFor(Level.ERROR)) {
        LOG.error("", new AssertionError("Current thread is " + Thread.currentThread() + ", but should be " + myThread));
      }
    }
  }
  public void setHadExceptions(boolean value) {
    myHadExceptions = value;
  }
  public boolean hadExceptions() {
    return myHadExceptions;
  }
  private class MyExecutorThread extends Thread {
    public MyExecutorThread(@NotNull String name) {
      super(name);
    }
    @Override
    public void run() {
      while (true) {
        if (myDisposed) {
          return;
        }
        Runnable task;
        synchronized (myQueue) {
          while (myQueue.isEmpty()) {
            try {
              myQueue.wait();
            } catch (InterruptedException e) {
              return;
            }
          }
          task = myQueue.poll();
        }
        try {
          task.run();
        } catch (Throwable e) {
          if (e instanceof InterruptedException || e.getCause() instanceof InterruptedException) {
            continue;
          }
          if (LOG.isEnabledFor(Level.ERROR)) {
            LOG.error(e.getClass().getName() + " exception in " + getName(), e);
          }
          myHadExceptions = true;
        }
      }
    }
  }
}