Unit Testing Multi-threaded Processes with Thread Weaver

thread-weaver - Project Hosting on Google Code

Thread Weaver is a framework for writing multi-threaded unit tests in Java.

It provides mechanisms for creating breakpoints within your code, and for halting execution of a thread when a breakpoint is reached. Other threads can then run while the first thread is blocked. This allows you to write repeatable tests for that can check for race conditions and thread safety.

This is a very interesting library. The example in the wiki is very helpful when learning how to use this.

DailyWTF: Walter Logged

Walter Logged - The Daily WTF

"You've gotta help us out," Thomas's client pleaded, "you know, work some of your Java magic or something. We've tried everything: double the RAM, upgrade the pipe, and add in more servers. But nothing seems to help: it's still slow as molasses."

Of course, had they listened to Thomas in the first place and not had Walter, their in-house developer, architect the transaction-processing system, they wouldn't be in this mess in the first place. As tempted as he was to say "I told you so," Thomas simply agreed to come in the next day and see what he could do.

"The good news is," his client said when he arrived on-site, "Walter said that it should be pretty easy to nail down the performance bottlenecks. He said he did a lot of logging."

And as it turned out, Walter was right about one thing: there was a lot of logging. A lot. Every method in every class was logged just as follows...

Thanks to DailyWTF for the funny code snippet. I ran into things like this on one of the projects I worked on in the past. The coding standard required that we include tracing on entering and exiting methods. Once they figured out that it made tracing worthless they changed the coding standard.