The library used is: http://l33tlabs.org/Continuations/ written by Matthias Mann
His library depends on ASM3 to parse and construct the bytecode: http://asm.ow2.org/
Through the Java Instrumentation Agent that I wrote for the previously mentioned library, there is no need to transform your byteclass ahead of time. The java agent will take care of this at runtime.
java -javaagent:conti4.jar -cp ./your.jars your.MainClass
I wrote a wrapper around the continuation library, to lower the bar a bit. I hope the code pretty much speaks for itself, and if not, feel free to ask questions. For additional convenience, I added some demo code and its fascinating output at the bottom.
Enjoy!
import de.matthiasmann.continuations.Coroutine; import de.matthiasmann.continuations.CoroutineProto; import de.matthiasmann.continuations.SuspendExecution; import de.matthiasmann.continuations.Coroutine.State; /* * Created on Nov 30, 2010 * * @author Riven */ public abstract class GreenThread implements CoroutineProto { public static final long EOF = -1L; private final Coroutine coroutine; public GreenThread() { this.coroutine = new Coroutine(this); } private long doSleep; @Override // this is where you put your code public abstract void coExecute() throws SuspendExecution; long step() { coroutine.run(); if (coroutine.getState() == State.FINISHED) return EOF; return this.doSleep; } public static void yield() throws SuspendExecution { GreenThread.sleep(0L); } public static void sleep(long ms) throws SuspendExecution { GreenThread thread = (GreenThread) Coroutine.getActiveCoroutine().getProto(); thread.doSleep = Math.max(ms, 0L); Coroutine.yield(); } } --------------------------------------------------------------------- import java.util.Comparator; import java.util.PriorityQueue; /* * Created on Nov 30, 2010 * * @author Riven */ public class GreenThreadQueue { private final PriorityQueuequeue; private final List reschedule; public GreenThreadQueue() { this.queue = new PriorityQueue (16, new GreenThreadWakeupComparator()); this.reschedule = new ArrayList (); } public void start(GreenThread thread) { this.queue.add(new GreenThreadWakeup(thread, 0L)); } public boolean tick(long now) { try { while (true) { GreenThreadWakeup wakeup = this.queue.peek(); if (wakeup == null) return !this.reschedule.isEmpty(); // signal nothing more to do if (wakeup.timestamp > now) break; if (this.queue.poll() != wakeup) throw new IllegalStateException(); long sleep = wakeup.thread.step(); if (sleep == GreenThread.EOF) continue; wakeup.timestamp = now + sleep; this.reschedule.add(wakeup); } return true; } finally { for (GreenThreadWakeup wakeup : this.reschedule) { this.queue.add(wakeup); } this.reschedule.clear(); } } static private class GreenThreadWakeup { public final GreenThread thread; public long timestamp; public GreenThreadWakeup(GreenThread thread, long timestamp) { this.thread = thread; this.timestamp = timestamp; } } static class GreenThreadWakeupComparator implements Comparator { @Override public int compare(GreenThreadWakeup o1, GreenThreadWakeup o2) { int val = Long.signum(o1.timestamp - o2.timestamp); return (val == 0) ? 1 : val; } } }
Demo code
GreenThreadQueue queue = new GreenThreadQueue();
GreenThread thread1 = new GreenThread()
{
@Override
public void coExecute() throws SuspendExecution
{
for (int i = 0; i < 3; i++)
{
System.out.println("a" + i);
GreenThread.sleep(1500);
}
}
};
GreenThread thread2 = new GreenThread()
{
@Override
public void coExecute() throws SuspendExecution
{
for (int i = 0; i < 4; i++)
{
System.out.println("b" + i);
GreenThread.sleep(1300);
}
}
};
queue.start(thread1);
queue.start(thread2);
do
{
try { Thread.sleep(100); } catch(InterruptedException exc) { /* ignore */ }
}
while (queue.tick(System.currentTimeMillis()));
}
a0 b0 b1 a1 b2 a2 b3
