Classes
class	RunLoop
class	TaskNode
interface	TimerRunnable
Public Member Functions
	BACITimer (ThreadFactory threadFactory)
Object	executeAt (Date date, TimerRunnable command)
Object	executeAfterDelay (long millisecondsToDelay, TimerRunnable command)
Object	executePeriodically (long period, TimerRunnable command, long firstTime)
synchronized Thread	getThread ()
synchronized void	shutDown ()
Static Public Member Functions
static void	cancel (Object taskID)
Protected Member Functions
synchronized void	clearThread ()
synchronized void	restart ()
synchronized TaskNode	nextTask ()
Protected Attributes
final Heap	heap_ = new Heap(64)
final ThreadFactory	threadFactory_
volatile boolean	shutdown_ = false
Thread	thread_
final RunLoop	runLoop_

Detailed Description

BACI timer. Based on EDU.oswego.cs.dl.util.concurrent (it was not approriate for BACI usage). Timer tasks should complete quickly. If a timer task takes excessive time to complete, it "hogs" the timer's task execution thread. This can, in turn, delay the execution of subsequent tasks, which may "bunch up" and execute in rapid succession when (and if) the offending task finally completes.

See also:: EDU.oswego.cs.dl.util.concurrent

Author:: Matej Sekoranja

Version:: $id$

Constructor & Destructor Documentation

alma.ACS.jbaci.BACITimer.BACITimer ( ThreadFactory threadFactory )

Constructor.

Parameters:

threadFactory thread factory to be used to create thread, if null no factory is being used

References alma.ACS.jbaci.BACITimer.runLoop_, and alma.ACS.jbaci.BACITimer.threadFactory_.

Member Function Documentation

static void alma.ACS.jbaci.BACITimer.cancel ( Object taskID ) [static]

Cancel a scheduled task that has not yet been run. The task will be cancelled upon the next opportunity to run it. This has no effect if this is a one-shot task that has already executed. Also, if an execution is in progress, it will complete normally. (It may however be interrupted via getThread().interrupt()). But if it is a periodic task, future iterations are cancelled.

Parameters:

taskID

-- a task reference returned by one of the execute commands

Exceptions:

ClassCastException

if the taskID argument is not of the type returned by an execute command.

synchronized void alma.ACS.jbaci.BACITimer.clearThread ( ) [protected]

set thread_ to null to indicate termination

References alma.ACS.jbaci.BACITimer.thread_.

Referenced by alma.ACS.jbaci.BACITimer.RunLoop.run().

Object alma.ACS.jbaci.BACITimer.executeAfterDelay	(	long	millisecondsToDelay,
		TimerRunnable	command
	)

Excecute the given command after waiting for the given delay.

Parameters:

	millisecondsToDelay	-- the number of milliseconds from now to run the command.
	command	-- the command to run after the delay.

Returns:: taskID -- an opaque reference that can be used to cancel execution request

References alma.ACS.jbaci.BACITimer.heap_, alma.ACS.jbaci.Heap.insert(), and alma.ACS.jbaci.BACITimer.restart().

Object alma.ACS.jbaci.BACITimer.executeAt	(	Date	date,
		TimerRunnable	command
	)

Execute the given command at the given time.

Parameters:

	date	-- the absolute time to run the command, expressed as a java.util.Date.
	command	-- the command to run at the given time.

Returns:: taskID -- an opaque reference that can be used to cancel execution request

References alma.ACS.jbaci.BACITimer.heap_, alma.ACS.jbaci.Heap.insert(), and alma.ACS.jbaci.BACITimer.restart().

Object alma.ACS.jbaci.BACITimer.executePeriodically	(	long	period,
		TimerRunnable	command,
		long	firstTime
	)

Execute the given command every period milliseconds AT FIXED RATE. If startNow is true, execution begins immediately, otherwise, it begins after the first period delay.

Parameters:

	period	-- the period, in milliseconds. Periods are measured from start-of-task to the next start-of-task. It is generally a bad idea to use a period that is shorter than the expected task duration.
	command	-- the command to run at each cycle
	firstTime	-- time when task should start with execution, 0 means immediately.

Exceptions:

IllegalArgumentException

if period less than or equal to zero.

Returns:: taskID -- an opaque reference that can be used to cancel execution request

References alma.ACS.jbaci.BACITimer.heap_, alma.ACS.jbaci.Heap.insert(), and alma.ACS.jbaci.BACITimer.restart().

synchronized Thread alma.ACS.jbaci.BACITimer.getThread ( )

Return the thread being used to process commands, or null if there is no such thread. You can use this to invoke any special methods on the thread, for example, to interrupt it.

References alma.ACS.jbaci.BACITimer.thread_.

synchronized TaskNode alma.ACS.jbaci.BACITimer.nextTask ( ) [protected]

Return the next task to execute, or null if thread is interrupted

References alma.ACS.jbaci.Heap.extract(), alma.ACS.jbaci.BACITimer.heap_, alma.ACS.jbaci.Heap.insert(), and alma.ACS.jbaci.Heap.peek().

Referenced by alma.ACS.jbaci.BACITimer.RunLoop.run().

synchronized void alma.ACS.jbaci.BACITimer.restart ( ) [protected]

Start (or restart) a thread to process commands, or wake up an existing thread if one is already running. This method can be invoked if the background thread crashed due to an unrecoverable exception in an executed command.

References alma.ACS.jbaci.BACITimer.runLoop_, alma.ACS.jbaci.BACITimer.shutdown_, alma.ACS.jbaci.BACITimer.thread_, and alma.ACS.jbaci.BACITimer.threadFactory_.

Referenced by alma.ACS.jbaci.BACITimer.executeAfterDelay(), alma.ACS.jbaci.BACITimer.executeAt(), and alma.ACS.jbaci.BACITimer.executePeriodically().

synchronized void alma.ACS.jbaci.BACITimer.shutDown ( )

Cancel all tasks and interrupt the background thread executing the current task, if any. A new background thread will be started if new execution requests are encountered. If the currently executing task does not repsond to interrupts, the current thread may persist, even if a new thread is started via restart().

References alma.ACS.jbaci.Heap.clear(), alma.ACS.jbaci.BACITimer.heap_, alma.ACS.jbaci.BACITimer.shutdown_, and alma.ACS.jbaci.BACITimer.thread_.

Referenced by alma.ACS.jbaci.BACIFramework.shutdown().