// Copyright 2017 JanusGraph Authors
//
// Licensed 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.janusgraph.graphdb.transaction.lock;
import com.google.common.base.Preconditions;
import org.janusgraph.diskstorage.util.time.Timer;
import org.janusgraph.diskstorage.util.time.TimestampProvider;
import java.time.Duration;
/**
* @author Matthias Broecheler (me@matthiasb.com)
*/
public class CombinerLock implements TransactionLock {
private final TransactionLock first;
private final TransactionLock second;
private final TimestampProvider times;
public CombinerLock(final TransactionLock first, final TransactionLock second, TimestampProvider times) {
this.first = first;
this.second = second;
this.times = times;
Preconditions.checkNotNull(this.first);
Preconditions.checkNotNull(this.second);
Preconditions.checkNotNull(this.times);
}
@Override
public void lock(Duration timeout) {
Timer t = times.getTimer().start();
first.lock(timeout);
Duration remainingTimeout = timeout.minus(t.elapsed());
try {
second.lock(remainingTimeout);
} catch (RuntimeException e) {
first.unlock();
throw e;
}
}
@Override
public void unlock() {
try {
first.unlock();
} finally {
second.unlock();
}
}
@Override
public boolean inUse() {
return first.inUse() || second.inUse();
}
}