org.multiverse.transactional.executors
Class TransactionalThreadPoolExecutor

java.lang.Object
  java.util.concurrent.AbstractExecutorService
      org.multiverse.transactional.executors.TransactionalThreadPoolExecutor

All Implemented Interfaces:

java.util.concurrent.Executor, java.util.concurrent.ExecutorService

public class TransactionalThreadPoolExecutor
extends java.util.concurrent.AbstractExecutorService

A transactional Executor implementation that looks a lot like the ThreadPoolExecutor.

Known concurrent limitations

1. no concurrent takes and puts
2. no concurrent takes (not really a big issue since the takes only have a very short transactions)
3. no concurrent puts

This will eventually be solved when a better queue implementation is found.

todo:

1. Shutdown now not implemented

Exception handling

If an Exception is thrown when a command is executed, it will not be logged and discarded instead. In the ThreadPoolExecutor it is possible to override the ThreadPoolExecutor.afterExecute(Runnable, Throwable) but this functionality isn't provided yet. So the best thing that you can do is wrap the command in a logging Runnable that catches and logs the exception.

A task executes by a TransactionalThreadPoolExecutor will not automatically receives its own transaction.

Author:

Peter Veentjer.

Constructor Summary

TransactionalThreadPoolExecutor()
Creates a new TransactionalThreadPoolExecutor with a unbound workqueue and 1 as corePoolSize and maxPoolSize.

TransactionalThreadPoolExecutor(java.util.concurrent.BlockingQueue<java.lang.Runnable> workQueue)
Creates a new TransactionalThreadPoolExecutor with the given workQueue and 1 as corePoolSize and maxPoolSize.

TransactionalThreadPoolExecutor(java.util.concurrent.BlockingQueue<java.lang.Runnable> workQueue, int corePoolSize)
Creates a new TransactionalThreadPoolExecutor.

TransactionalThreadPoolExecutor(int poolSize)
Creates a new TransactionalThreadPool with an unbound workqueue and the provided poolSize.

Method Summary

void	awaitTermination() Awaits for this TransactionalThreadPoolExecutor to complete.
boolean	awaitTermination(long timeout, java.util.concurrent.TimeUnit unit)
void	awaitTerminationUninterruptibly() Awaits for this TransactionalThreadPoolExecutor to complete without the possibility of being interrupted.
void	execute(java.lang.Runnable command)
int	getCorePoolSize() Returns the minimum number of threads in this TransactionalThreadPoolExecutor.
int	getCurrentPoolSize() Returns the current number of threads in this TransactionalThreadPoolExecutor.
org.multiverse.transactional.executors.TransactionalThreadPoolExecutor.State	getState() Returns the State this TransactionalThreadPoolExecutor has.
java.util.concurrent.ThreadFactory	getThreadFactory() Returns the thread factory used to create new threads.
java.util.concurrent.BlockingQueue<java.lang.Runnable>	getWorkQueue() Returns the BlockingQueue this TransactionalThreadPoolExecutor uses to store unprocessed work.
boolean	isShutdown()
boolean	isStarted()
boolean	isTerminated()
void	setCorePoolSize(int newCorePoolSize) Sets the corePoolSize of this TransactionalThreadPoolExecutor.
void	setThreadFactory(java.util.concurrent.ThreadFactory threadFactory) Sets the thread factory used to create new threads.
void	shutdown()
java.util.List<java.lang.Runnable>	shutdownNow()
void	start() Starts this TransactionalThreadPoolExecutor.

Methods inherited from class java.util.concurrent.AbstractExecutorService

invokeAll, invokeAll, invokeAny, invokeAny, newTaskFor, newTaskFor, submit, submit, submit

Methods inherited from class java.lang.Object

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

Constructor Detail

TransactionalThreadPoolExecutor

public TransactionalThreadPoolExecutor()

Creates a new TransactionalThreadPoolExecutor with a unbound workqueue and 1 as corePoolSize and maxPoolSize.

If no limit is placed on the workQueue is could lead to a system not degrading gracefull because it runs out of memory instead of rejecting tasks.

TransactionalThreadPoolExecutor

public TransactionalThreadPoolExecutor(int poolSize)

Creates a new TransactionalThreadPool with an unbound workqueue and the provided poolSize.

Parameters:

poolSize - the maximum and core poolsize.

Throws:

java.lang.IllegalArgumentException - if poolSize smaller than 0.

TransactionalThreadPoolExecutor

public TransactionalThreadPoolExecutor(java.util.concurrent.BlockingQueue<java.lang.Runnable> workQueue)

Creates a new TransactionalThreadPoolExecutor with the given workQueue and 1 as corePoolSize and maxPoolSize.

Parameters:

workQueue - the BlockingQueue to store unprocessed work.

Throws:

java.lang.NullPointerException - if workQueue is null.

TransactionalThreadPoolExecutor

public TransactionalThreadPoolExecutor(java.util.concurrent.BlockingQueue<java.lang.Runnable> workQueue,
                                       int corePoolSize)

Creates a new TransactionalThreadPoolExecutor.

Parameters:

workQueue - the BlockingQueue to store unprocessed work.

corePoolSize - the minimum number of threads in this TransactionalThreadPoolExecutor.

Throws:

java.lang.NullPointerException - if workQueue is null.

java.lang.IllegalArgumentException - if corePoolSize is smaller than zero or if maxPoolSize smaller than corePoolSize.

Method Detail

getCorePoolSize

public int getCorePoolSize()

Returns the minimum number of threads in this TransactionalThreadPoolExecutor. The returned value will always be equal or larger than zero.

Returns:

the minimum number of threads in this TransactionalThreadPoolExecutor.

setCorePoolSize

public void setCorePoolSize(int newCorePoolSize)

Sets the corePoolSize of this TransactionalThreadPoolExecutor. If the TransactionalThreadPoolExecutor is unstarted, it isn't started. If the newCorePoolSize is larger than the maximumPoolSize, it automatically sets the maxPoolSize to newCorePoolSize.

Parameters:

newCorePoolSize - the new core poolsize.

Throws:

java.lang.IllegalArgumentException - if newCorePoolSize is smaller than 0.

java.lang.IllegalStateException - if this TransactionalThreadPoolExecutor is shutdown or terminated.

getCurrentPoolSize

public int getCurrentPoolSize()

Returns the current number of threads in this TransactionalThreadPoolExecutor.

Returns:

the current number of threads.

getWorkQueue

public java.util.concurrent.BlockingQueue<java.lang.Runnable> getWorkQueue()

Returns the BlockingQueue this TransactionalThreadPoolExecutor uses to store unprocessed work.

Returns:

the BlockingQueue used to store unprocessed work.

getState

public org.multiverse.transactional.executors.TransactionalThreadPoolExecutor.State getState()

Returns the State this TransactionalThreadPoolExecutor has.

Returns:

the State this TransactionalThreadPoolExecutor has.

setThreadFactory

public void setThreadFactory(java.util.concurrent.ThreadFactory threadFactory)

Sets the thread factory used to create new threads.

Parameters:

threadFactory - the new thread factory

Throws:

java.lang.NullPointerException - if threadFactory is null

See Also:

getThreadFactory()

getThreadFactory

public java.util.concurrent.ThreadFactory getThreadFactory()

Returns the thread factory used to create new threads.

Returns:

the current thread factory

See Also:

setThreadFactory(java.util.concurrent.ThreadFactory)

shutdown

public void shutdown()

shutdownNow

public java.util.List<java.lang.Runnable> shutdownNow()

isShutdown

public boolean isShutdown()

isTerminated

public boolean isTerminated()

isStarted

public boolean isStarted()

awaitTermination

public boolean awaitTermination(long timeout,
                                java.util.concurrent.TimeUnit unit)
                         throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

awaitTermination

public void awaitTermination()
                      throws java.lang.InterruptedException

Awaits for this TransactionalThreadPoolExecutor to complete. This call can be interrupted.

Throws:

java.lang.InterruptedException - if the Thread was interrupted.

awaitTerminationUninterruptibly

public void awaitTerminationUninterruptibly()

Awaits for this TransactionalThreadPoolExecutor to complete without the possibility of being interrupted.

execute

public void execute(java.lang.Runnable command)

start

public void start()

Starts this TransactionalThreadPoolExecutor. If the TransactionalThreadPoolExecutor already is started, the call is ignored.

Throws:

java.lang.IllegalStateException - if the this TransactionalThreadPoolExecutor already is shutdown or terminated.