Module java.base

Package java.dyn

Class Coroutine

java.lang.Object

java.dyn.CoroutineBase

java.dyn.Coroutine

public class Coroutine
extends CoroutineBase

Implementation of symmetric coroutines. A Coroutine will take part in thread-wide scheduling of coroutines. It transfers control to the next coroutine whenever yield is called.

Similar to Thread there are two ways to implement a Coroutine: either by implementing a subclass of Coroutine (and overriding CoroutineBase.run()) or by providing a Runnable to the Coroutine constructor.

An implementation of a simple Coroutine might look like this:

 class Numbers extends Coroutine {
        public void run() {
                for (int i = 0; i < 10; i++) {
                        System.out.println(i);
                        yield();
        }
    }
 }
 

A Coroutine is active as soon as it is created, and will run as soon as control is transferred to it:

 new Numbers();
 for (int i = 0; i < 10; i++)
        yield();
 

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Coroutine.StealResult	the result for steal

Constructor Summary

Constructors

Constructor	Description
Coroutine()	Allocates a new Coroutine object.
Coroutine(long stacksize)	Allocates a new Coroutine object.
Coroutine(Runnable target)	Allocates a new Coroutine object.
Coroutine(Runnable target, long stacksize)	Allocates a new Coroutine object.

Method Summary

Modifier and Type	Method	Description
StackTraceElement[]	getCoroutineStack()	get StackTrace element for coroutine
void	setWispTask(int id, Object task, Object engine)	Relate Coroutine to wisp data structures
Coroutine.StealResult	steal(boolean failOnContention)	Steal a coroutine from it's carrier thread to current thread.
void	stop()	Coroutine exit.
static void	unsafeYieldTo(Coroutine target)	optimized version of yieldTo function for wisp based on the following assumptions: 1. we won't simultaneously steal a Coroutine from other threads 2. we won't switch to a Coroutine that's being stolen 3. we won't steal a running Coroutine
static void	yieldTo(Coroutine target)	Yields execution to the target coroutine.

Methods declared in class java.dyn.CoroutineBase

current, getThread, isFinished, run

Methods declared in class java.lang.Object

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

Constructor Detail

Coroutine

public Coroutine()

Allocates a new Coroutine object.

Coroutine

public Coroutine(Runnable target)

Allocates a new Coroutine object.

Parameters:

target - the runnable

Coroutine

public Coroutine(long stacksize)

Allocates a new Coroutine object.

Parameters:

stacksize - the size of stack

Coroutine

public Coroutine(Runnable target,
                 long stacksize)

Allocates a new Coroutine object.

Parameters:

target - runnable

stacksize - the size of stack

Method Detail

yieldTo

public static void yieldTo(Coroutine target)

Yields execution to the target coroutine.

Parameters:

target - Coroutine

unsafeYieldTo

public static void unsafeYieldTo(Coroutine target)

optimized version of yieldTo function for wisp based on the following assumptions: 1. we won't simultaneously steal a Coroutine from other threads 2. we won't switch to a Coroutine that's being stolen 3. we won't steal a running Coroutine

Parameters:

target - target coroutine

steal

public Coroutine.StealResult steal(boolean failOnContention)

Steal a coroutine from it's carrier thread to current thread.

Parameters:

failOnContention - steal fail if there's too much lock contention

Returns:

result described by Coroutine.STEAL_*. Also return SUCCESS directly if coroutine's carrier thread is current.

stop

public void stop()

Coroutine exit.

setWispTask

public void setWispTask(int id,
                        Object task,
                        Object engine)

Relate Coroutine to wisp data structures

Parameters:

id - wispTask id

task - task oop

engine - wispEngine oop

getCoroutineStack

public StackTraceElement[] getCoroutineStack()

get StackTrace element for coroutine

Returns:

StackTraceElement