/*
* JBoss, Home of Professional Open Source
* Copyright 2010, Red Hat Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.as.ejb3.component.interceptors;
import static java.lang.Math.max;
import java.lang.reflect.UndeclaredThrowableException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.jboss.as.ejb3.logging.EjbLogger;
import org.wildfly.common.Assert;
/**
* runnable used to invoke local ejb async methods
*
* @author Stuart Douglas
*/
public abstract class AsyncInvocationTask implements Runnable, Future<Object> {
private final CancellationFlag cancelledFlag;
private static final int ST_RUNNING = 0;
private static final int ST_DONE = 1;
private static final int ST_CANCELLED = 2;
private static final int ST_FAILED = 3;
private volatile int status = ST_RUNNING;
private Object result;
private Exception failed;
public AsyncInvocationTask(final CancellationFlag cancelledFlag) {
this.cancelledFlag = cancelledFlag;
}
@Override
public synchronized boolean cancel(final boolean mayInterruptIfRunning) {
if (status != ST_RUNNING) {
return status == ST_CANCELLED;
}
if (cancelledFlag.cancel(mayInterruptIfRunning)) {
status = ST_CANCELLED;
done();
return true;
}
return false;
}
protected abstract Object runInvocation() throws Exception;
public void run() {
synchronized (this) {
if (! cancelledFlag.runIfNotCancelled()) {
status = ST_CANCELLED;
done();
return;
}
}
Object result;
try {
result = runInvocation();
} catch (Exception e) {
setFailed(e);
return;
}
Future<?> asyncResult = (Future<?>) result;
try {
if(asyncResult != null) {
result = asyncResult.get();
}
} catch (InterruptedException e) {
setFailed(new IllegalStateException(e));
return;
} catch (ExecutionException e) {
try {
throw e.getCause();
} catch (Exception ex) {
setFailed(ex);
return;
} catch (Throwable throwable) {
setFailed(new UndeclaredThrowableException(throwable));
return;
}
}
setResult(result);
return;
}
private synchronized void setResult(final Object result) {
this.result = result;
status = ST_DONE;
done();
}
private synchronized void setFailed(final Exception e) {
this.failed = e;
status = ST_FAILED;
done();
}
private void done() {
notifyAll();
}
@Override
public boolean isCancelled() {
return status == ST_CANCELLED;
}
@Override
public boolean isDone() {
return status == ST_DONE;
}
@Override
public synchronized Object get() throws InterruptedException, ExecutionException {
for (;;) switch (status) {
case ST_RUNNING: wait(); break;
case ST_CANCELLED: throw EjbLogger.ROOT_LOGGER.taskWasCancelled();
case ST_FAILED: throw new ExecutionException(failed);
case ST_DONE: return result;
default: throw Assert.impossibleSwitchCase(status);
}
}
@Override
public synchronized Object get(final long timeout, final TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
long remaining = unit.toNanos(timeout);
long start = System.nanoTime();
for (;;) switch (status) {
case ST_RUNNING: {
if (remaining <= 0L) {
throw EjbLogger.ROOT_LOGGER.failToCompleteTaskBeforeTimeOut(timeout, unit);
}
// round up to the nearest millisecond
wait((remaining + 999_999L) / 1_000_000L);
remaining -= max(0L, System.nanoTime() - start);
break;
}
case ST_CANCELLED: throw EjbLogger.ROOT_LOGGER.taskWasCancelled();
case ST_FAILED: throw new ExecutionException(failed);
case ST_DONE: return result;
default: throw Assert.impossibleSwitchCase(status);
}
}
}