Package org.kiwiproject.concurrent

Class TryLocker

java.lang.Object

org.kiwiproject.concurrent.TryLocker

public class TryLocker
extends Object

Utility that aids in using Lock.tryLock(long, TimeUnit).

This can also make unit testing easier by allowing easy mocking.

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_LOCK_WAIT_TIME	The default lock wait time if not specified.
static TimeUnit	DEFAULT_LOCK_WAIT_TIME_UNIT	The default lock wait time unit if not specified.

Method Summary

Modifier and Type	Method	Description
Duration	getLockWaitDuration()	Return the maximum lock wait time as a Duration.
static TryLocker	using(Lock lock, long maxWaitTime, TimeUnit maxWaitTimeUnit)	Create a new TryLocker using the given lock and maximum wait time.
static TryLocker	usingReentrantLock()	Create a new TryLocker using a ReentrantLock and the default lock maximum wait time.
static TryLocker	usingReentrantLock(int maxWaitTime, TimeUnit maxWaitTimeUnit)	Create a new TryLocker using a ReentrantLock with the given lock wait time.
void	withLockOrElse(Runnable withLockAction, Runnable orElseAction)	Run withLockAction if the lock is obtained within the lock timeout period.
<T> T	withLockSupplyOrFallback(Supplier<T> withLockSupplier, T fallbackValue)	Execute the given withLockSupplier if the lock is obtained within the lock timeout period and return its value.
<T> T	withLockSupplyOrFallbackSupply(Supplier<T> withLockSupplier, Supplier<T> fallbackSupplier)	Execute the given withLockSupplier if the lock is obtained within the lock timeout period and return its value.
<T> T	withLockSupplyOrNull(Supplier<T> withLockSupplier)	Execute the given withLockSupplier if the lock is obtained within the lock timeout period and return its value.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_LOCK_WAIT_TIME

public static final int DEFAULT_LOCK_WAIT_TIME

The default lock wait time if not specified.

See Also:

Constant Field Values

DEFAULT_LOCK_WAIT_TIME_UNIT

public static final TimeUnit DEFAULT_LOCK_WAIT_TIME_UNIT

The default lock wait time unit if not specified.

Method Detail

usingReentrantLock

public static TryLocker usingReentrantLock()

Create a new TryLocker using a ReentrantLock and the default lock maximum wait time.

Returns:

a new instance

See Also:

DEFAULT_LOCK_WAIT_TIME, DEFAULT_LOCK_WAIT_TIME_UNIT

usingReentrantLock

public static TryLocker usingReentrantLock(int maxWaitTime,
                                           TimeUnit maxWaitTimeUnit)

Create a new TryLocker using a ReentrantLock with the given lock wait time.

Parameters:

maxWaitTime - maximum lock wait time

maxWaitTimeUnit - maximum lock wait time value

Returns:

a new instance

using

public static TryLocker using(Lock lock,
                              long maxWaitTime,
                              TimeUnit maxWaitTimeUnit)

Create a new TryLocker using the given lock and maximum wait time.

Parameters:

lock - the Lock to use

maxWaitTime - maximum lock wait time

maxWaitTimeUnit - maximum lock wait time value

Returns:

a new instance

getLockWaitDuration

public Duration getLockWaitDuration()

Return the maximum lock wait time as a Duration.

Returns:

the lock wait duration

withLockOrElse

public void withLockOrElse(Runnable withLockAction,
                           Runnable orElseAction)

Run withLockAction if the lock is obtained within the lock timeout period. Otherwise run orElseAction.

Parameters:

withLockAction - action to run if lock is obtained

orElseAction - action to run if lock is not obtained

withLockSupplyOrNull

public <T> T withLockSupplyOrNull(Supplier<T> withLockSupplier)

Execute the given withLockSupplier if the lock is obtained within the lock timeout period and return its value. Otherwise return null.

Type Parameters:

T - type of object returned

Parameters:

withLockSupplier - supplier to execute if lock is obtained

Returns:

the supplied value or null

withLockSupplyOrFallback

public <T> T withLockSupplyOrFallback(Supplier<T> withLockSupplier,
                                      T fallbackValue)

Execute the given withLockSupplier if the lock is obtained within the lock timeout period and return its value. Otherwise return the fallbackValue.

Type Parameters:

T - type of object returned

Parameters:

withLockSupplier - supplier to execute if lock is obtained

fallbackValue - the value to use if the lock is not obtained

Returns:

the supplied value or the fallback value

withLockSupplyOrFallbackSupply

public <T> T withLockSupplyOrFallbackSupply(Supplier<T> withLockSupplier,
                                            Supplier<T> fallbackSupplier)

Execute the given withLockSupplier if the lock is obtained within the lock timeout period and return its value. Otherwise return the valued supplied by fallbackSupplier.

Type Parameters:

T - type of object returned

Parameters:

withLockSupplier - supplier to execute if lock is obtained

fallbackSupplier - the supplier to execute if the lock is not obtained

Returns:

the supplied value or the supplied fallback value