org.apache.tika.batch.Interrupter Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.tika.batch;
import java.io.InputStream;
import java.util.concurrent.Callable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Class that waits for input on System.in. If this reads
* EOF or if there is an exception from the parent's IO,
* this will send a signal to shutdown the forked process.
*
* This will call System.exit(-1) if the process
* doesn't stop after {@link #pauseOnEarlyTermination}
* milliseconds.
*
*/
public class Interrupter implements Callable {
private static final Logger LOG = LoggerFactory.getLogger(Interrupter.class);
private static final long EXTRA_GRACE_PERIOD_MILLIS = 1000;
private final long pauseOnEarlyTermination;
public Interrupter(long pauseOnEarlyTermination) {
this.pauseOnEarlyTermination = pauseOnEarlyTermination;
}
public IFileProcessorFutureResult call() {
try {
InputStream is = System.in;
int byt = is.read();
while (byt > -1) {
byt = is.read();
}
} catch (Throwable e) {
LOG.warn("Exception from STDIN in CommandlineInterrupter.", e);
}
new Thread(new Doomsday()).start();
return new InterrupterFutureResult();
}
private class Doomsday implements Runnable {
@Override
public void run() {
if (pauseOnEarlyTermination < 0) {
return;
}
long start = System.currentTimeMillis();
long elapsed = System.currentTimeMillis() - start;
while (elapsed < (pauseOnEarlyTermination + EXTRA_GRACE_PERIOD_MILLIS)) {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
return;
}
elapsed = System.currentTimeMillis() - start;
}
LOG.error("Interrupter timed out; now calling System.exit.");
System.exit(-1);
}
}
}