org.infinispan.util.concurrent.locks
Class DeadlockDetectingLockManager

java.lang.Object
  org.infinispan.util.concurrent.locks.LockManagerImpl
      org.infinispan.util.concurrent.locks.DeadlockDetectingLockManager

All Implemented Interfaces:

LockManager

public class DeadlockDetectingLockManager
extends LockManagerImpl

Lock manager in charge with processing deadlock detections. Implementation notes: if a deadlock is detected, then one of the transactions has to rollback. The transaction that rollbacks is determined by comparing the coin toss from DldGlobalTransaction. A thread calling LockManager.lockAndRecord(Object, org.infinispan.context.InvocationContext, long) would run the deadlock detection algorithm only if all of the following take place: - the call is made in the scope of a transaction (either locally originated or remotely originated) - it cannot acquire lock on the given key and the lock owner is another transaction - when comparing coin toss, this thread would loose against the other one - so it's always the potential loser that runs DLD. If deadlock is detected then LockManager.lockAndRecord(Object, org.infinispan.context.InvocationContext, long) would throw an DeadlockDetectedException. This is subsequently handled in in the interceptor chain - locks owned by this tx are released.

Author:

Mircea.Markus@jboss.com

Field Summary

protected boolean	exposeJmxStats
protected long	spinDuration

Fields inherited from class org.infinispan.util.concurrent.locks.LockManagerImpl

configuration, lockContainer, trace

Constructor Summary

DeadlockDetectingLockManager()

Method Summary

long	getDetectedLocalDeadlocks()
long	getDetectedRemoteDeadlocks()
static long	getLocallyInterruptedTransactions() Deprecated.
long	getOverlapWithNotDeadlockAwareLockOwners()
long	getTotalNumberOfDetectedDeadlocks()
void	init()
boolean	lockAndRecord(Object key, InvocationContext ctx, long lockTimeout) Acquires a lock of type lockType, on a specific entry in the cache.
void	resetStatistics()
void	setExposeJmxStats(boolean exposeJmxStats)

Methods inherited from class org.infinispan.util.concurrent.locks.LockManagerImpl

acquireLock, acquireLock, acquireLockNoCheck, getConcurrencyLevel, getLockAcquisitionTimeout, getLockId, getNumberOfLocksAvailable, getNumberOfLocksHeld, getOwner, injectDependencies, isLocked, ownsLock, possiblyLocked, printLockInfo, unlock, unlockAll

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

spinDuration

protected volatile long spinDuration

exposeJmxStats

protected volatile boolean exposeJmxStats

Constructor Detail

DeadlockDetectingLockManager

public DeadlockDetectingLockManager()

Method Detail

init

public void init()

lockAndRecord

public boolean lockAndRecord(Object key,
                             InvocationContext ctx,
                             long lockTimeout)
                      throws InterruptedException

Description copied from interface: LockManager

Acquires a lock of type lockType, on a specific entry in the cache. This method will try for a period of time and give up if it is unable to acquire the required lock. The period of time is specified in Configuration.getLockAcquisitionTimeout().

Specified by:

lockAndRecord in interface LockManager

Overrides:

lockAndRecord in class LockManagerImpl

Parameters:

key - key to lock

ctx - invocation context associated with this invocation

Returns:

true if the lock was acquired, false otherwise.

Throws:

InterruptedException - if interrupted

setExposeJmxStats

public void setExposeJmxStats(boolean exposeJmxStats)

getTotalNumberOfDetectedDeadlocks

public long getTotalNumberOfDetectedDeadlocks()

resetStatistics

public void resetStatistics()

getDetectedRemoteDeadlocks

public long getDetectedRemoteDeadlocks()

getDetectedLocalDeadlocks

public long getDetectedLocalDeadlocks()

getOverlapWithNotDeadlockAwareLockOwners

public long getOverlapWithNotDeadlockAwareLockOwners()

getLocallyInterruptedTransactions

@Deprecated
public static long getLocallyInterruptedTransactions()

Deprecated.