Package org.opendaylight.infrautils.utils.concurrent

Class NamedLocks<T>

java.lang.Object

org.opendaylight.infrautils.utils.concurrent.NamedLocks<T>

Type Parameters:

T - the name type, required to be effectively immutable where T.hashCode() and T.equals() is concerned

public final class NamedLocks<T>
extends Object

Manages multiple ReentrantLocks identified by a unique name.

Example of use of lock():

     NamedLocks<String> locks;
     String lockName;

     try (Acquired lock = locks.Acquire(lockName)) {
          // locked region
     }

     // lock released
 

Example of use of tryLock():

     NamedLocks<String> locks;
     String lockName;

     try (AcquireResult lock = locks.tryAcquire(lockName)) {
         // maybe locked region

         if (lock.wasAcquired()) {
             // locked region
         } else {
             // unlocked region
         }
     });

     // lock released
 

Author:

Robert Varga

Constructor Summary

Constructors

Constructor	Description
NamedLocks()

Method Summary

Modifier and Type	Method	Description
NamedSimpleReentrantLock.Acquired	acquire(T lockKey)	Acquires the lock for the given key.
NamedSimpleReentrantLock<T>	getLock(T lockKey)
NamedSimpleReentrantLock.AcquireResult	tryAcquire(T lockName)	Acquires the lock for the given key only if it is not held by another thread at the time of invocation.
NamedSimpleReentrantLock.AcquireResult	tryAcquire(T lockName, long timeout, TimeUnit unit)	Tries to acquire the lock for the given key if it is not held by another thread within the given waiting time.

Methods inherited from class java.lang.Object

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

Constructor Detail

NamedLocks

public NamedLocks()

Method Detail

tryAcquire

public NamedSimpleReentrantLock.AcquireResult tryAcquire(T lockName,
                                                         long timeout,
                                                         TimeUnit unit)

Tries to acquire the lock for the given key if it is not held by another thread within the given waiting time. See ReentrantLock.tryLock(long, TimeUnit) for more details.

Parameters:

lockName - the key to lock

timeout - the time to wait for the lock

unit - the time unit of the timeout argument

Returns:

lock operation result. If the lock was free and was acquired by the current thread, NamedSimpleReentrantLock.AcquireResult.wasAcquired() will return true. If it reports false, the locking attempt failed, either due to lock time expiring or the thread being interrupted while waiting.

tryAcquire

public NamedSimpleReentrantLock.AcquireResult tryAcquire(T lockName)

Acquires the lock for the given key only if it is not held by another thread at the time of invocation. See ReentrantLock.tryLock() for more details.

Parameters:

lockName - the key to lock

Returns:

lock operation result. If the lock was free and was acquired by the current thread, NamedSimpleReentrantLock.AcquireResult.wasAcquired() will return true. If it reports false, the locking attempt failed, because another thread is currently holding the lock.

acquire

public NamedSimpleReentrantLock.Acquired acquire(T lockKey)

Acquires the lock for the given key. See ReentrantLock.lock() for more details.

Parameters:

lockKey - the key to lock

getLock

public NamedSimpleReentrantLock<T> getLock(T lockKey)