Thread: Code Profilers?

I've been tasked with improving the performance of a piece of software at work, which means I need to find a profiler- not only to help track down problematic code, but maybe even more importantly, to measure how much I've actually improved the system.

There are some basic things I could do, such as timing how long it takes for a method to run (or how long it takes to run 1000 times). However, the systems at work are not the most reliable machines, so that type of performance can depend on how many people are using a machine, what processes are running, which direction the wind is blowing at that moment, etc. So in a perfect world I'd find a profiler that will give me data that's more useful than raw times.

I'm usually an opponent of optimization (unless things are unusable, and in this case they are), so I don't really know anything about profilers. I'm using a program called FindBugs that will point out potentially crappy pieces of code, but I'm still not quite sure how to actually measure the performance. I've looked into JProfiler, but that's apparently not free.

I'm going to send out an email at work asking their opinion, but I thought I'd check here to see if you guys have any experience with something I haven't heard about. Thanks for your time.

I'll definitely check that out. I'm not sure how much the System.nanoTime() will help me- on a predictable machine it absolutely would, but not so much on my highly variable work machines. But the VisualVM seems pretty handy. Thanks.

My 0.02

If you are required to provide some form of evidence that an improvement has been made for the benefit of the company then they should fork out the coin to provide you with the necessary tools to achieve your goals.

Their metric is "this takes a godawful long time to complete". It's a huge company so I'd be surprised if we didn't have access to some kind of profiling tool, but to my knowledge none has been used on this piece of software yet. But since this is mostly a "figure out how to do this and then do it" type task, I figured I'd educate myself as much as possible before writing any emails.

Eclipse has the TPTP plugin - which I never have the patience to install so I haven't tried it - that you might wish to check out. Another tool is jconsole, which lets you visualize what's going on in a running java app. Java VisualVM is another tool you might want to look at as well. Note I haven't used these extensively (I prefer the old fashioned currentTimeMillis approach)