interrupting threads

[CornedBee]

The documentation is confusing me on this.

What I want is having a thread sleep until I give it a GO signal. How would I do this? I have looked into sleep() and interrupt(), but I don't really understand it. What does the "interrupted" state mean? Is it related to the running state of the thread? If yes, how? If no, how do I get the running state?

I want to be able to stop the thread again with another signal. How would I do that? suspend, stop etc. are deprecated.

Thanks in advance

[CornedBee]

I now use a signaling model with Object.wait() and Object.notify(), but I don't undestand their documentation either, so it might not work. Especially the parts about monitor ownership.

On a related note, is there something like a critical section in Java? I have several threads, and most of them might want to access one global java.awt.Robot object, I have to synchronize the access.

Here's the signaling code I currently use:

class SomeClass implements Runnable
{
	private Object startSignal;
	private boolean running;
	private Thread solver;

	public SomeClass()
	{
		startSignal = new Object();
		solver = new Thread(this);
		setRunning(false);
		solver.start();
	}

	public void startstop()
	{
		if(isRunning()) {
			setRunning(false);
		} else {
			setRunning(true);
			startSignal.notify();
		}
	}

	synchronized boolean isRunning()
	{
		return running;
	}

	synchronized void setRunning(boolean r)
	{
		running = r;
	}

	// this might cause huge synchronization problems...
	public void run()
	{
		while(true) {
			startSignal.wait();
			while(isRunning()) {
				internalStep();
			}
		}
	}
}

internalStep does calculations.

[CornedBee]

The problem is that there might (and will) be several objects of SomeClass, each having it's own thread trying to access the same java.awt.Robot

[HairyDave]

http://java.sun.com/docs/books/tutor...o/threads.html

Any use? Theres some stuff on synchronising blocks etc.

HD

[Dillinger4]

From what i remember of multithreadding the sleep method is used to put the thread to sleep for a period of time specified by the arguement passed to the method.

Calling wait() causes the current thread to block until the objects notify() method is called by another thread.

[CornedBee]

Dave: seems interesting, thanks.

Dilenger: yeah, that's about the part of the docs I understood . Nothing else.

[CornedBee]

Dave: just found out it's exactly what I needed. Double thanks.