Comments for Rambling about...

Comment on SWT tip: Using SelectionAdapter by Josh Suereth

Josh Suereth — Tue, 20 May 2008 12:03:21 +0000

I just recently figured this out myself! I had actually used SelectionAdapter from sample code, just never bothered to look close enough at the code I wasn’t tweaking.

Comment on UML, the fast way with Violet by Abel Muiño

Abel Muiño — Thu, 08 May 2008 22:28:37 +0000

Hi Alexandre. Although I would like to contribute to almost any project that crosses my way, truth is that Q for Eclipse is the only one I can seriously dedicate time to.

However… if Maven somehow crosses in the way of Violet, I would be happy to help with the Eclipse support.

Or, if you use maven to build Violet, maybe you would like to try q4e

Comment on UML, the fast way with Violet by Alexandre de Pellegrin

Alexandre de Pellegrin — Thu, 01 May 2008 08:20:17 +0000

Hi Abel,

Thank you very much for this feedback about Violet. We’re still working on the next release. Cay has produced a “bug free” sequence diagram and I’ve just introduced a smaller tool bar to improve Eclipse integration. A major refinement will be the new XMI exporting and code generation for class diagrams (developed by Frederic Aoustin).

Don’t hesitate to contribute to this project. For example, I need to introduced friendly docs on each diagram on the web site. The aim is to be a “learning” UML tool.

Regards,
Alex dP

PS : I forgot to precise this : I’m the Violet’s project leader.

Comment on Deadlock quiz… the answer by Erle Czar Mantos

Erle Czar Mantos — Thu, 17 Apr 2008 03:51:58 +0000

Nice puzzle … couldn’t have figured it out myself.

Comment on Deadlock quiz by Abel Muiño

Abel Muiño — Thu, 10 Apr 2008 19:52:47 +0000

I’ve posted an explanation in a new post.

Comment on Deadlock quiz by Allan Ramirez

Allan Ramirez — Thu, 10 Apr 2008 09:53:30 +0000

After t.start() is called, the caller thread would return and the other thread (t) would call run method.

The other thread (t) cannot call run method because the caller thread still holds the lock. Therefore the other thread (t) will always be alive and the caller thread will be stucked to while block forever.

Comment on Deadlock quiz by Piotr Smolinski

Piotr Smolinski — Tue, 08 Apr 2008 08:22:20 +0000

Consider slight modification:

public static final String A = “Hello World”;
public static final String B = “Hello World”.toLowerCase();

(…

public void run() {
System.out.println(A);
System.out.println(B);
}

The code locks on System.out.println(B);
If you remove also synchronized section from launchThread() and use Thread.sleep(100) the situation is the same.

In my opinion this is due to different initialization of A and B. The first one is literal (compile-time constant) while the second one must be initialized. Therefore JVM delays B access until class is statically initialized (which happens when the thread ends).

Comment on Deadlock quiz by matthewsteele

matthewsteele — Mon, 07 Apr 2008 15:49:36 +0000

I’ve been reading up on concurrency in Java all weekend, and I’m still no closer to figuring this out.

Does it have to do with the object being locked is the class (since you’re performing synchronized() in a singleton), as opposed to an instance of the object?

I give up. What’s the answer?

Comment on Deadlock quiz by Abel Muiño

Abel Muiño — Fri, 04 Apr 2008 16:40:33 +0000

run() is called from Thread.start(), since the class implements Runnable (Lines 17, 1

Comment on Deadlock quiz by matthewsteele

matthewsteele — Fri, 04 Apr 2008 16:34:03 +0000

Why is A_STRING and run() part of the class? It doesn’t seem like it’s getting called anywhere…