com.smartwerkz.jupload.classic.util.concurrent
Class Executor

java.lang.Object
  com.smartwerkz.jupload.classic.util.concurrent.Executor

public class Executor
extends java.lang.Object

Used for executing background tasks. You can add tasks to a queue that the Executor will work through. Also a finalTask can be set that will be executed whenever the Executor finished performing a task and the queue is empty. While executing the final task, the Executor is still busy.
Some critical operations are synchronized against each other to avoid any ambigious results when calling eg start and stop at the same time from different threads.

Since:

Jan 26, 2006, 7:21:34 PM

Author:

Dominik Seifert

Field Summary

protected Task	currentTask
protected ObservedThread	thread

Constructor Summary

Executor(java.lang.String id, java.lang.String name)
Creates a new Executor that uses the given name.

Method Summary

boolean	busy() Indicates that the Executor is currently performing a task.
boolean	cancelled() Indicates wether this Executor's tasks have just been cancelled.
boolean	cancelTasks() Cancels all current tasks and the loading thread will idle as soon as it finished its current task (if it has any).
Task	getCurrentTask()
static java.util.List	getExecutors(java.lang.String id)
java.lang.String	getName() Returns the name of the Executor's thread.
java.lang.Thread	getThread()
Validator	getValidator() Will stop accepting when the current or next set of tasks has been cancelled.
boolean	hasTasks() Indicates that there are tasks enqueued that are waiting to be executed.
boolean	isRunning() Returns true if the executor has been started with start()
void	performLater(Task task) Enqueues a new task to be performed by the Executor.
void	resume() Will resume this Executor if suspended.
void	setFinalTask(java.lang.Runnable task) Sets the final task which will be executed -if not null- after every time the executor executed all tasks (a task has been executed and the queue is empty) and before it starts waiting for the next.
void	start() Starts execution.
boolean	suspend(boolean join) Suspends the Executor.
boolean	suspended() Indicates wether or not this Executor is suspended.
void	terminate(boolean join) Terminates the Executor (call init to restart it).
static void	terminateAll(java.lang.String id) Terminates all Executors with the given id.
java.lang.String	toString()
boolean	waiting() Indicates wether the Executor is currently idle and not suspended, thus ready to instantly perform any new task.

Methods inherited from class java.lang.Object

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

Field Detail

thread

protected ObservedThread thread

currentTask

protected Task currentTask

Constructor Detail

Executor

public Executor(java.lang.String id,
                java.lang.String name)

Creates a new Executor that uses the given name. The ID must be the same for all instances within one jupload context. Thus using the config's id is recommended.

Parameters:

id - the id under which this executor will be stored, unique within one jupload context

name - the name of the executor

Method Detail

start

public void start()

Starts execution.

getName

public java.lang.String getName()

Returns the name of the Executor's thread. Useless if this Executor has been cancelled.

terminate

public void terminate(boolean join)

Terminates the Executor (call init to restart it). If join is true, the calling thread can be ensured that after calling this method, the Executor will be terminated.

Parameters:

join - Indicates that in case, the Executor is currently performing a task, the calling thread should wait for it to finish.

cancelTasks

public boolean cancelTasks()

Cancels all current tasks and the loading thread will idle as soon as it finished its current task (if it has any).

Returns:

Wether this executor is currently busy

performLater

public void performLater(Task task)

Enqueues a new task to be performed by the Executor.

getThread

public java.lang.Thread getThread()

getCurrentTask

public Task getCurrentTask()

Returns:

The task which is currently executed or null.

hasTasks

public boolean hasTasks()

Indicates that there are tasks enqueued that are waiting to be executed. Also with no tasks, the Executor can still be uploading, performing a task.

busy

public boolean busy()

Indicates that the Executor is currently performing a task.

waiting

public boolean waiting()

Indicates wether the Executor is currently idle and not suspended, thus ready to instantly perform any new task.

suspended

public boolean suspended()

Indicates wether or not this Executor is suspended. Also a suspended Executor might still be uploading if it did not finish its last task yet.

suspend

public boolean suspend(boolean join)

Suspends the Executor. If join is true, the calling thread can be ensured that after calling this method, the Executor will be suspended.

Parameters:

join - Indicates that in case, the Executor is currently performing a task, the calling thread should wait for it to finish.

Returns:

Wether it is now idle or -if returning false- still uploading with its last task.

resume

public void resume()

Will resume this Executor if suspended.

setFinalTask

public void setFinalTask(java.lang.Runnable task)

Sets the final task which will be executed -if not null- after every time the executor executed all tasks (a task has been executed and the queue is empty) and before it starts waiting for the next.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getExecutors

public static java.util.List getExecutors(java.lang.String id)

Returns:

A list of Executors with the given id or null if the id does not exist.

terminateAll

public static void terminateAll(java.lang.String id)

Terminates all Executors with the given id.

isRunning

public boolean isRunning()

Returns true if the executor has been started with start()

Returns:

true if the executor has been started, or false if it has been terminated or not yet been started or t

cancelled

public boolean cancelled()

Indicates wether this Executor's tasks have just been cancelled.

getValidator

public Validator getValidator()

Will stop accepting when the current or next set of tasks has been cancelled.