Module org.tquadrat.foundation.base

Package org.tquadrat.foundation.lang

Interface AutoLock

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

AutoLockImpl

@ClassVersion(sourceVersion="$Id: AutoLock.java 1097 2024-02-06 20:10:12Z tquadrat $")
@API(status=STABLE,
     since="0.1.0")
public sealed interface AutoLock
extends AutoCloseable
permits AutoLockImpl

A wrapper for locks that supports the try-with-resources feature of Java 7.

Instead of

  m_Lock.lock();
  try
  {
      …
  }
  finally
  {
      m_Lock.unlock();
  }

you can write now

  private final AutoLock m_AutoLock = AutoLock.of();

  …

  try( final var ignored = m_AutoLock.lock() )
  {
      …
  }

The creation of the local reference to the wrapper object means some overhead but in very most scenarios this is negligible.

AutoLock will only expose the methods lock() and lockInterruptibly() of the interface Lock, but with a return value. Exposing other methods is not reasonable.

Calling close() on the AutoLock instance or Lock.unlock() on the wrapped Lock object inside the try block may cause unpredictable effects.

Author:

Thomas Thrien (thomas.thrien@tquadrat.org)

Version:

$Id: AutoLock.java 1097 2024-02-06 20:10:12Z tquadrat $

Since:

0.1.0

See Also:

• Lock

UML Diagram

⁠

UML Diagram for "org.tquadrat.foundation.lang.AutoLock"

⁠

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static final class	AutoLock.ExecutionFailedException	This exception is thrown when an operation fails.

Method Summary

Modifier and Type	Method	Description
void	close()
boolean	evaluate(Constraint constraint)	Evaluates the given Constraint after obtaining the lock, and returns its result.
void	execute(Action action)	Executes the given action after obtaining the lock.
<R> Optional<R>	execute(Operation<? extends R> operation)	Executes the given operation after obtaining the lock, and returns its result.
Lock	getWrappedLockInstance()	Returns the wrapped lock.
AutoLock	lock()	Calls lock() on the wrapped Lock instance.
AutoLock	lockInterruptibly()	Calls lockInterruptibly() on the wrapped Lock instance.
Condition	newCondition()	Returns a new Condition instance that is bound to the instance of Lock that is wrapped by this AutoLock instance.
static AutoLock	of()	Creates a new AutoLock instance with an internal lock object.
static AutoLock	of(Lock lock)	Creates a new AutoLock instance from the given Lock instance.

Method Details

close

void close()

Specified by:

close in interface AutoCloseable

evaluate

boolean evaluate(Constraint constraint)
          throws AutoLock.ExecutionFailedException

Evaluates the given Constraint after obtaining the lock, and returns its result.

Parameters:

constraint - The constraint

Returns:

The evaluation result.

Throws:

AutoLock.ExecutionFailedException - The evaluation failed for some reason.

execute

void execute(Action action)
      throws AutoLock.ExecutionFailedException

Executes the given action after obtaining the lock.

Parameters:

action - The action.

Throws:

AutoLock.ExecutionFailedException - The action failed for some reason.

execute

<R> Optional<R> execute(Operation<? extends R> operation)
                 throws AutoLock.ExecutionFailedException

Executes the given operation after obtaining the lock, and returns its result.

Type Parameters:

R - The type of the operation's result.

Parameters:

operation - The operation.

Returns:

An instance of Optional that holds the result of the operation.

Throws:

AutoLock.ExecutionFailedException - The operation failed for some reason.

getWrappedLockInstance

Lock getWrappedLockInstance()

Returns the wrapped lock.

Returns:

The wrapped lock.

lock

AutoLock lock()

Calls lock() on the wrapped Lock instance.

Returns:

The reference to this AutoLock instance.

lockInterruptibly

AutoLock lockInterruptibly()
                    throws InterruptedException

Calls lockInterruptibly() on the wrapped Lock instance.

Returns:

The reference to this AutoLock instance.

Throws:

InterruptedException - The current thread was interrupted while acquiring the lock (and interruption of lock acquisition is supported).

newCondition

Condition newCondition()

Returns a new Condition instance that is bound to the instance of Lock that is wrapped by this AutoLock instance.

Returns:

The new condition.

Throws:

UnsupportedOperationException - The wrapped lock's implementation does not support conditions.

See Also:

• Lock.newCondition()

of

@API(status=STABLE,
     since="0.0.5")
static AutoLock of()

Creates a new AutoLock instance with an internal lock object.

Returns:

The new instance.

of

@API(status=STABLE,
     since="0.0.5")
static AutoLock of(Lock lock)

Creates a new AutoLock instance from the given Lock instance.

Parameters:

lock - The wrapped lock.

Returns:

The new instance.