Package kilim

Class Task<TT>

java.lang.Object

kilim.Task<TT>

All Implemented Interfaces:

java.lang.Runnable, EventSubscriber, Fiber.Worker

Direct Known Subclasses:

Chain, Continuation.FakeTask, Ex, Group.GroupTask, NioSelectorScheduler.RegistrationTask, PerfTest, PerfTest.Producer1, Pure.TaskDemo, Reflect, SessionTask, SimpleTask, SimpleTask2, Task.Fork, Task.Invoke, Task.Spawn, TaskGroup, TimedTask, TimerBlast, TimerBlast.Tick, TimerBlast2.Tick, TimerBlast2.Tock, Userdata

public abstract class Task<TT>
extends java.lang.Object
implements java.lang.Runnable, EventSubscriber, Fiber.Worker

A base class for tasks. A task is a lightweight thread (it contains its own stack in the form of a fiber). A concrete subclass of Task must provide a pausable execute method.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	Task.ArgState
static class	Task.Fork
static class	Task.Invoke<TT>
static class	Task.Spawn<TT>

Field Summary

Fields

Modifier and Type	Field	Description
private static boolean	debugRunning
protected boolean	done
private java.util.LinkedList<Mailbox<ExitMsg<TT>>>	exitMBs
java.lang.Object	exitResult
protected Fiber	fiber	The stack manager in charge of rewinding and unwinding the stack when Task.pause() is called.
int	id	Task id, automatically generated
(package private) static java.util.concurrent.atomic.AtomicInteger	idSource
(package private) int	numActivePins
protected PauseReason	pauseReason	The reason for pausing (duh) and performs the role of a await condition in CCS.
(package private) int	preferredResumeThread	The thread in which to resume this task.
private static Fiber.MethodRef	runnerInfo
protected java.util.concurrent.atomic.AtomicBoolean	running	running = true when it is put on the schdulers run Q (by Task.resume()).
protected Scheduler	scheduler	The object responsible for handing this task to a thread when the task is runnable.
private int	tid
Timer	timer
(package private) static PauseReason	yieldReason

Constructor Summary

Constructors

Constructor	Description
Task()
Task(boolean dummy)

Method Summary

Modifier and Type	Method	Description
void	checkKill()
(package private) void	checkPin()
(package private) boolean	checkTimeout()
java.lang.String	dump()
boolean	equals(java.lang.Object obj)
static void	errNotWoven()
static void	errNotWoven(Task t)
static void	errorExit(java.lang.Throwable ex)	Exit the task with a throwable indicating an error condition.
static void	errorExit(java.lang.Throwable ex, Fiber f)
void	execute()
void	execute(Fiber f)
static void	exit(java.lang.Object aExitValue)	Analogous to System.exit, except an Object can be used as the exit value
static void	exit(java.lang.Object aExitValue, Fiber f)
static Task	fork(Pausable.Fork body)	Wraps the given object or lambda expression in a Task and starts that task.
static Task	getCurrentTask()	This is a placeholder that doesn't do anything useful.
java.lang.Thread	getExecutionThread()
PauseReason	getPauseReason()
(package private) Fiber.MethodRef	getRunnerInfo()
Scheduler	getScheduler()
static int	getStackDepth(Task task)	The generated code calls Fiber.upEx, which in turn calls this to find out out where the current method is w.r.t the closest _runExecute method.
boolean	getState()
int	getTid()	return the thread ID that the task is currently running on, valid only during execute
private static java.lang.reflect.Method	getWovenMethod(java.lang.reflect.Method m)
int	hashCode()
int	id()
static void	idledown()	idledown the default scheduler
void	informOnExit(Mailbox<ExitMsg<TT>> exit)
static java.lang.Object	invoke(java.lang.reflect.Method method, java.lang.Object obj, java.lang.Object... args)	Invoke a pausable method via reflection.
boolean	isDone()
ExitMsg<TT>	join()
ExitMsg<TT>	joinb()
void	onEvent(EventPublisher ep, Event e)
static void	pause(PauseReason pauseReason)	Ask the current task to pause with a reason object, that is responsible for resuming the task when the reason (for pausing) is not valid any more.
static void	pause(PauseReason pauseReason, Fiber f)
void	pinToThread()
void	prePin()
boolean	resume()	Add itself to scheduler if it is neither already running nor done.
void	resumeOnScheduler(Scheduler s)
void	run()	Called by WorkerThread, it is the wrapper that performs pre and post execute processing (in addition to calling the execute(fiber) method of the task.
protected void	setPauseReason(PauseReason pr)
Task<TT>	setScheduler(Scheduler s)
protected void	setTid(int tid)
static void	shutdown()
private static boolean	skipInvoke(java.lang.String klass, java.lang.String name)
static void	sleep(long millis)
static Task.Invoke	spawn(java.lang.reflect.Method method, java.lang.Object obj, java.lang.Object... args)
static <TT> Task.Spawn<TT>	spawn(Pausable.Spawn<TT> body)	Wraps the given object or lambda expression in a Task and starts that task.
Task<TT>	start()	Used to start the task; the task doesn't resume on its own.
java.lang.String	toString()
void	unpinFromThread()
static void	yield()	Yield cooperatively to the next task waiting to use the thread.
static void	yield(Fiber f)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

yieldReason

static PauseReason yieldReason

id

public final int id

Task id, automatically generated

idSource

static final java.util.concurrent.atomic.AtomicInteger idSource

fiber

protected Fiber fiber

The stack manager in charge of rewinding and unwinding the stack when Task.pause() is called.

pauseReason

protected PauseReason pauseReason

The reason for pausing (duh) and performs the role of a await condition in CCS. This object is responsible for resuming the task.

See Also:

PauseReason

running

protected java.util.concurrent.atomic.AtomicBoolean running

running = true when it is put on the schdulers run Q (by Task.resume()). The Task.runExecute() method is called at some point; 'running' remains true until the end of runExecute (where it is reset), at which point a fresh decision is made whether the task needs to continue running.

done

protected volatile boolean done

preferredResumeThread

volatile int preferredResumeThread

The thread in which to resume this task. Ideally, we shouldn't have any preferences, but using locks in pausable methods will require the task to be pinned to a thread.

See Also:

ReentrantLock

tid

private int tid

numActivePins

int numActivePins

See Also:

preferredResumeThread

exitMBs

private java.util.LinkedList<Mailbox<ExitMsg<TT>>> exitMBs

See Also:

informOnExit(Mailbox)

scheduler

protected Scheduler scheduler

The object responsible for handing this task to a thread when the task is runnable.

exitResult

public volatile java.lang.Object exitResult

timer

public Timer timer

debugRunning

private static boolean debugRunning

runnerInfo

private static Fiber.MethodRef runnerInfo

Constructor Detail

Task

public Task()

Task

Task(boolean dummy)

Method Detail

id

public int id()

setScheduler

public Task<TT> setScheduler(Scheduler s)

getScheduler

public Scheduler getScheduler()

resumeOnScheduler

public void resumeOnScheduler(Scheduler s)
                       throws Pausable

Throws:

Pausable

start

public Task<TT> start()

Used to start the task; the task doesn't resume on its own. Custom schedulers must be set (@see #setScheduler(Scheduler)) before start() is called.

Returns:

getRunnerInfo

Fiber.MethodRef getRunnerInfo()

skipInvoke

private static boolean skipInvoke(java.lang.String klass,
                                  java.lang.String name)

getStackDepth

public static int getStackDepth(Task task)

The generated code calls Fiber.upEx, which in turn calls this to find out out where the current method is w.r.t the closest _runExecute method.

Returns:

the number of stack frames above _runExecute(), not including this method

checkTimeout

boolean checkTimeout()

onEvent

public void onEvent(EventPublisher ep,
                    Event e)

Specified by:

onEvent in interface EventSubscriber

getExecutionThread

public java.lang.Thread getExecutionThread()

resume

public boolean resume()

Add itself to scheduler if it is neither already running nor done.

Returns:

True if it scheduled itself.

informOnExit

public void informOnExit(Mailbox<ExitMsg<TT>> exit)

getCurrentTask

public static Task getCurrentTask()
                           throws Pausable

This is a placeholder that doesn't do anything useful. Weave replaces the call in the bytecode from invokestateic Task.getCurrentTask to load fiber getfield task

Throws:

Pausable

exit

public static void exit(java.lang.Object aExitValue)
                 throws Pausable

Analogous to System.exit, except an Object can be used as the exit value

Throws:

Pausable

exit

public static void exit(java.lang.Object aExitValue,
                        Fiber f)

errorExit

public static void errorExit(java.lang.Throwable ex)
                      throws Pausable

Exit the task with a throwable indicating an error condition. The value is conveyed through the exit mailslot (see informOnExit). All exceptions trapped by the task scheduler also set the error result.

Throws:

Pausable

errorExit

public static void errorExit(java.lang.Throwable ex,
                             Fiber f)

errNotWoven

public static void errNotWoven()

errNotWoven

public static void errNotWoven(Task t)

invoke

public static java.lang.Object invoke(java.lang.reflect.Method method,
                                      java.lang.Object obj,
                                      java.lang.Object... args)
                               throws Pausable,
                                      java.lang.IllegalAccessException,
                                      java.lang.IllegalArgumentException,
                                      java.lang.reflect.InvocationTargetException

Invoke a pausable method via reflection. Equivalent to Method.invoke().

Parameters:

method - : The method to be invoked. (Implementation note: the corresponding woven method is invoked instead).

obj - : The object on which the method is invoked. Can be null if the method is static.

args - : Arguments to the method

Returns:

Throws:

Pausable

java.lang.IllegalAccessException

java.lang.IllegalArgumentException

java.lang.reflect.InvocationTargetException

getWovenMethod

private static java.lang.reflect.Method getWovenMethod(java.lang.reflect.Method m)

sleep

public static void sleep(long millis)
                  throws Pausable

Parameters:

millis - to sleep. Like thread.sleep, except it doesn't throw an interrupt, and it doesn't hog the java thread.

Throws:

Pausable

shutdown

public static void shutdown()

yield

public static void yield()
                  throws Pausable

Yield cooperatively to the next task waiting to use the thread.

Throws:

Pausable

yield

public static void yield(Fiber f)

pause

public static void pause(PauseReason pauseReason)
                  throws Pausable

Ask the current task to pause with a reason object, that is responsible for resuming the task when the reason (for pausing) is not valid any more.

Parameters:

pauseReason - the reason

Throws:

Pausable

pause

public static void pause(PauseReason pauseReason,
                         Fiber f)

execute

public void execute()
             throws Pausable,
                    java.lang.Exception

Specified by:

execute in interface Fiber.Worker

Throws:

Pausable

java.lang.Exception

execute

public void execute(Fiber f)
             throws java.lang.Exception

Specified by:

execute in interface Fiber.Worker

Throws:

java.lang.Exception

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

dump

public java.lang.String dump()

prePin

public void prePin()
            throws Pausable

Throws:

Pausable

checkPin

void checkPin()

pinToThread

public void pinToThread()

unpinFromThread

public void unpinFromThread()

setPauseReason

protected final void setPauseReason(PauseReason pr)

getPauseReason

public final PauseReason getPauseReason()

isDone

public boolean isDone()

setTid

protected void setTid(int tid)

getTid

public int getTid()

return the thread ID that the task is currently running on, valid only during execute

run

public void run()
         throws NotPausable

Called by WorkerThread, it is the wrapper that performs pre and post execute processing (in addition to calling the execute(fiber) method of the task.

Specified by:

run in interface java.lang.Runnable

Throws:

NotPausable

joinb

public ExitMsg<TT> joinb()

join

public ExitMsg<TT> join()
                 throws Pausable

Throws:

Pausable

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

checkKill

public void checkKill()

getState

public boolean getState()

fork

public static Task fork(Pausable.Fork body)

Wraps the given object or lambda expression in a Task and starts that task. Beware of inadvertent sharing when multiple lambdas are created in the same context

Parameters:

body - the lambda to delegate to

Returns:

the spawned task.

spawn

public static <TT> Task.Spawn<TT> spawn(Pausable.Spawn<TT> body)

Wraps the given object or lambda expression in a Task and starts that task. Beware of inadvertent sharing when multiple lambdas are created in the same context

Parameters:

body - the lambda to delegate to

Returns:

the spawned task.

spawn

public static Task.Invoke spawn(java.lang.reflect.Method method,
                                java.lang.Object obj,
                                java.lang.Object... args)

idledown

public static void idledown()

idledown the default scheduler

See Also:

Scheduler.idledown()