com.google.inject.internal

Class CycleDetectingLock.CycleDetectingLockFactory.ReentrantCycleDetectingLock<ID>

java.lang.Object

com.google.inject.internal.CycleDetectingLock.CycleDetectingLockFactory.ReentrantCycleDetectingLock<ID>

All Implemented Interfaces:

CycleDetectingLock<ID>

Enclosing class:

CycleDetectingLock.CycleDetectingLockFactory<ID>

static class CycleDetectingLock.CycleDetectingLockFactory.ReentrantCycleDetectingLock<ID>
extends java.lang.Object
implements CycleDetectingLock<ID>

The implementation for CycleDetectingLock.

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.inject.internal.CycleDetectingLock

CycleDetectingLock.CycleDetectingLockFactory<ID>

Field Summary

Fields

Modifier and Type	Field and Description
private CycleDetectingLock.CycleDetectingLockFactory<ID>	lockFactory Factory that was used to create this lock.
private java.util.concurrent.locks.Lock	lockImplementation Underlying lock used for actual waiting when no potential deadlocks are detected.
private java.lang.Long	lockOwnerThreadId Thread id for the thread that owned this lock.
private int	lockReentranceCount Number of times that thread owned this lock.
private ID	userLockId User id for this lock.

Constructor Summary

Constructors

Constructor and Description
ReentrantCycleDetectingLock(CycleDetectingLock.CycleDetectingLockFactory<ID> lockFactory, ID userLockId, java.util.concurrent.locks.Lock lockImplementation)

Method Summary

Modifier and Type	Method and Description
(package private) void	checkState() Check consistency of an internal state.
private com.google.common.collect.ListMultimap<java.lang.Long,ID>	detectPotentialLocksCycle() Algorithm to detect a potential lock cycle.
private java.util.List<ID>	getAllLockIdsAfter(long threadId, CycleDetectingLock.CycleDetectingLockFactory.ReentrantCycleDetectingLock lock) Return locks owned by a thread after a lock specified, inclusive.
com.google.common.collect.ListMultimap<java.lang.Long,ID>	lockOrDetectPotentialLocksCycle() Takes a lock in a blocking fashion in case no potential deadlocks are detected.
java.lang.String	toString()
void	unlock() Unlocks previously locked lock.

Methods inherited from class java.lang.Object

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

Field Detail

lockImplementation

private final java.util.concurrent.locks.Lock lockImplementation

Underlying lock used for actual waiting when no potential deadlocks are detected.

userLockId

private final ID userLockId

User id for this lock.

lockFactory

private final CycleDetectingLock.CycleDetectingLockFactory<ID> lockFactory

Factory that was used to create this lock.

lockOwnerThreadId

private java.lang.Long lockOwnerThreadId

Thread id for the thread that owned this lock. Nullable. Guarded by CycleDetectingLockFactory.this.

lockReentranceCount

private int lockReentranceCount

Number of times that thread owned this lock. Guarded by CycleDetectingLockFactory.this.

Constructor Detail

ReentrantCycleDetectingLock

ReentrantCycleDetectingLock(CycleDetectingLock.CycleDetectingLockFactory<ID> lockFactory,
                            ID userLockId,
                            java.util.concurrent.locks.Lock lockImplementation)

Method Detail

lockOrDetectPotentialLocksCycle

public com.google.common.collect.ListMultimap<java.lang.Long,ID> lockOrDetectPotentialLocksCycle()

Description copied from interface: CycleDetectingLock

Takes a lock in a blocking fashion in case no potential deadlocks are detected. If the lock was successfully owned, returns an empty map indicating no detected potential deadlocks. Otherwise, a map indicating threads involved in a potential deadlock are returned. Map is ordered by dependency cycle and lists locks for each thread that are part of the loop in order. Returned map is created atomically. In case no cycle is detected performance is O(threads creating singletons), in case cycle is detected performance is O(singleton locks).

Specified by:

lockOrDetectPotentialLocksCycle in interface CycleDetectingLock<ID>

unlock

public void unlock()

Description copied from interface: CycleDetectingLock

Unlocks previously locked lock.

Specified by:

unlock in interface CycleDetectingLock<ID>

checkState

void checkState()
         throws java.lang.IllegalStateException

Check consistency of an internal state.

Throws:

java.lang.IllegalStateException

detectPotentialLocksCycle

private com.google.common.collect.ListMultimap<java.lang.Long,ID> detectPotentialLocksCycle()

Algorithm to detect a potential lock cycle. For lock's thread owner check which lock is it trying to take. Repeat recursively. When current thread is found a potential cycle is detected.

See Also:

CycleDetectingLock.lockOrDetectPotentialLocksCycle()

getAllLockIdsAfter

private java.util.List<ID> getAllLockIdsAfter(long threadId,
                                              CycleDetectingLock.CycleDetectingLockFactory.ReentrantCycleDetectingLock lock)

Return locks owned by a thread after a lock specified, inclusive.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object