com.google.common.util.concurrent

Class CycleDetectingLockFactory.LockGraphNode

java.lang.Object

com.google.common.util.concurrent.CycleDetectingLockFactory.LockGraphNode

Enclosing class:

CycleDetectingLockFactory

private static class CycleDetectingLockFactory.LockGraphNode
extends java.lang.Object

A LockGraphNode associated with each lock instance keeps track of the directed edges in the lock acquisition graph.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) java.util.Map<CycleDetectingLockFactory.LockGraphNode,CycleDetectingLockFactory.ExampleStackTrace>	allowedPriorLocks The map tracking the locks that are known to be acquired before this lock, each associated with an example stack trace.
(package private) java.util.Map<CycleDetectingLockFactory.LockGraphNode,CycleDetectingLockFactory.PotentialDeadlockException>	disallowedPriorLocks The map tracking lock nodes that can cause a lock acquisition cycle if acquired before this node.
(package private) java.lang.String	lockName

Constructor Summary

Constructors

Constructor and Description
LockGraphNode(java.lang.String lockName)

Method Summary

Modifier and Type	Method and Description
(package private) void	checkAcquiredLock(CycleDetectingLockFactory.Policy policy, CycleDetectingLockFactory.LockGraphNode acquiredLock) Checks the acquisition-ordering between this, which is about to be acquired, and the specified acquiredLock.
(package private) void	checkAcquiredLocks(CycleDetectingLockFactory.Policy policy, java.util.List<CycleDetectingLockFactory.LockGraphNode> acquiredLocks)
private CycleDetectingLockFactory.ExampleStackTrace	findPathTo(CycleDetectingLockFactory.LockGraphNode node, java.util.Set<CycleDetectingLockFactory.LockGraphNode> seen) Performs a depth-first traversal of the graph edges defined by each node's allowedPriorLocks to find a path between this and the specified lock.
(package private) java.lang.String	getLockName()

Methods inherited from class java.lang.Object

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

Field Detail

allowedPriorLocks

final java.util.Map<CycleDetectingLockFactory.LockGraphNode,CycleDetectingLockFactory.ExampleStackTrace> allowedPriorLocks

The map tracking the locks that are known to be acquired before this lock, each associated with an example stack trace. Locks are weakly keyed to allow proper garbage collection when they are no longer referenced.

disallowedPriorLocks

final java.util.Map<CycleDetectingLockFactory.LockGraphNode,CycleDetectingLockFactory.PotentialDeadlockException> disallowedPriorLocks

The map tracking lock nodes that can cause a lock acquisition cycle if acquired before this node.

lockName

final java.lang.String lockName

Constructor Detail

LockGraphNode

LockGraphNode(java.lang.String lockName)

Method Detail

getLockName

java.lang.String getLockName()

checkAcquiredLocks

void checkAcquiredLocks(CycleDetectingLockFactory.Policy policy,
                        java.util.List<CycleDetectingLockFactory.LockGraphNode> acquiredLocks)

checkAcquiredLock

void checkAcquiredLock(CycleDetectingLockFactory.Policy policy,
                       CycleDetectingLockFactory.LockGraphNode acquiredLock)

Checks the acquisition-ordering between this, which is about to be acquired, and the specified acquiredLock.

When this method returns, the acquiredLock should be in either the preAcquireLocks map, for the case in which it is safe to acquire this after the acquiredLock, or in the disallowedPriorLocks map, in which case it is not safe.

findPathTo

@Nullable
private CycleDetectingLockFactory.ExampleStackTrace findPathTo(CycleDetectingLockFactory.LockGraphNode node,
                                                                         java.util.Set<CycleDetectingLockFactory.LockGraphNode> seen)

Performs a depth-first traversal of the graph edges defined by each node's allowedPriorLocks to find a path between this and the specified lock.

Returns:

If a path was found, a chained CycleDetectingLockFactory.ExampleStackTrace illustrating the path to the lock, or null if no path was found.