/*
* Copyright 2011 Red Hat, Inc. and/or its affiliates.
*
* 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
package org.infinispan.configuration.cache;
import org.infinispan.util.concurrent.IsolationLevel;
/**
* Defines the local, in-VM locking and concurrency characteristics of the cache.
*
* @author pmuir
*
*/
public class LockingConfiguration {
private final int concurrencyLevel;
private final IsolationLevel isolationLevel;
private long lockAcquisitionTimeout;
private final boolean useLockStriping;
private final boolean writeSkewCheck;
LockingConfiguration(int concurrencyLevel, IsolationLevel isolationLevel, long lockAcquisitionTimeout,
boolean useLockStriping, boolean writeSkewCheck) {
this.concurrencyLevel = concurrencyLevel;
this.isolationLevel = isolationLevel;
this.lockAcquisitionTimeout = lockAcquisitionTimeout;
this.useLockStriping = useLockStriping;
this.writeSkewCheck = writeSkewCheck;
}
/**
* Concurrency level for lock containers. Adjust this value according to the number of concurrent
* threads interacting with Infinispan. Similar to the concurrencyLevel tuning parameter seen in
* the JDK's ConcurrentHashMap.
*/
public int concurrencyLevel() {
return concurrencyLevel;
}
/**
* Cache isolation level. Infinispan only supports READ_COMMITTED or REPEATABLE_READ isolation
* levels. See <a href=
* 'http://en.wikipedia.org/wiki/Isolation_level'>http://en.wikipedia.org/wiki/Isolation_level</a
* > for a discussion on isolation levels.
*/
public IsolationLevel isolationLevel() {
return isolationLevel;
}
/**
* Maximum time to attempt a particular lock acquisition
*/
public long lockAcquisitionTimeout() {
return lockAcquisitionTimeout;
}
public LockingConfiguration lockAcquisitionTimeout(long lockAcquisitionTimeout) {
this.lockAcquisitionTimeout = lockAcquisitionTimeout;
return this;
}
/**
* If true, a pool of shared locks is maintained for all entries that need to be locked.
* Otherwise, a lock is created per entry in the cache. Lock striping helps control memory
* footprint but may reduce concurrency in the system.
*/
public boolean useLockStriping() {
return useLockStriping;
}
/**
* This setting is only applicable in the case of REPEATABLE_READ. When write skew check is set
* to false, if the writer at commit time discovers that the working entry and the underlying
* entry have different versions, the working entry will overwrite the underlying entry. If true,
* such version conflict - known as a write-skew - will throw an Exception.
*/
public boolean writeSkewCheck() {
return writeSkewCheck;
}
@Override
public String toString() {
return "LockingConfiguration{" +
"concurrencyLevel=" + concurrencyLevel +
", isolationLevel=" + isolationLevel +
", lockAcquisitionTimeout=" + lockAcquisitionTimeout +
", useLockStriping=" + useLockStriping +
", writeSkewCheck=" + writeSkewCheck +
'}';
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
LockingConfiguration that = (LockingConfiguration) o;
if (concurrencyLevel != that.concurrencyLevel) return false;
if (lockAcquisitionTimeout != that.lockAcquisitionTimeout) return false;
if (useLockStriping != that.useLockStriping) return false;
if (writeSkewCheck != that.writeSkewCheck) return false;
if (isolationLevel != that.isolationLevel) return false;
return true;
}
@Override
public int hashCode() {
int result = concurrencyLevel;
result = 31 * result + (isolationLevel != null ? isolationLevel.hashCode() : 0);
result = 31 * result + (int) (lockAcquisitionTimeout ^ (lockAcquisitionTimeout >>> 32));
result = 31 * result + (useLockStriping ? 1 : 0);
result = 31 * result + (writeSkewCheck ? 1 : 0);
return result;
}
}