package org.infinispan.util.concurrent.locks.containers;
import net.jcip.annotations.ThreadSafe;
import org.infinispan.util.concurrent.locks.VisibleOwnerReentrantLock;
import org.infinispan.util.concurrent.locks.VisibleOwnerRefCountingReentrantLock;
import org.infinispan.util.logging.Log;
import org.infinispan.util.logging.LogFactory;
import java.util.Arrays;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReentrantLock;
/**
* A LockContainer that holds ReentrantLocks
*
* @author Manik Surtani (<a href="mailto:manik@jboss.org">manik@jboss.org</a>)
* @see OwnableReentrantStripedLockContainer
* @since 4.0
*/
@ThreadSafe
public class ReentrantStripedLockContainer extends AbstractStripedLockContainer<VisibleOwnerReentrantLock> {
private VisibleOwnerReentrantLock[] sharedLocks;
private static final Log log = LogFactory.getLog(ReentrantStripedLockContainer.class);
@Override
protected Log getLog() {
return log;
}
/**
* Creates a new LockContainer which uses a certain number of shared locks across all elements that need to be
* locked.
*
* @param concurrencyLevel concurrency level for number of stripes to create. Stripes are created in powers of two,
* with a minimum of concurrencyLevel created.
*/
public ReentrantStripedLockContainer(int concurrencyLevel) {
initLocks(calculateNumberOfSegments(concurrencyLevel));
}
@Override
protected void initLocks(int numLocks) {
sharedLocks = new VisibleOwnerReentrantLock[numLocks];
for (int i = 0; i < numLocks; i++) sharedLocks[i] = new VisibleOwnerReentrantLock();
}
@Override
public final VisibleOwnerReentrantLock getLock(Object object) {
return sharedLocks[hashToIndex(object)];
}
@Override
public final int getNumLocksHeld() {
int i = 0;
for (ReentrantLock l : sharedLocks)
if (l.isLocked()) {
i++;
}
return i;
}
@Override
public int size() {
return sharedLocks.length;
}
@Override
public final boolean ownsLock(Object object, Object ignored) {
ReentrantLock lock = getLock(object);
return lock.isHeldByCurrentThread();
}
@Override
public final boolean isLocked(Object object) {
ReentrantLock lock = getLock(object);
return lock.isLocked();
}
public String toString() {
return "ReentrantStripedLockContainer{" +
"sharedLocks=" + (sharedLocks == null ? null : Arrays.asList(sharedLocks)) +
'}';
}
@Override
protected void unlock(VisibleOwnerReentrantLock l, Object unused) {
l.unlock();
}
@Override
protected boolean tryLock(VisibleOwnerReentrantLock lock, long timeout, TimeUnit unit, Object unused) throws InterruptedException {
return lock.tryLock(timeout, unit);
}
@Override
protected void lock(VisibleOwnerReentrantLock lock, Object lockOwner) {
lock.lock();
}
}