On his Oracle blog Chris Jones has shared more details about using DTrace for dynamic tracing of the execution of your application. In this new post he looks more specifically at using it to trace through a PHPUnit test for a functional programming example.
I was reading the article Functional Programming in PHP by Patkos Csaba and wondering how efficient this type of programming is. I thought this would be a good time to fire up DTrace and see what is going on. Since DTrace is "always available" even in production machines (once PHP is compiled with --enable-dtrace), this was easy to do.
Using the code provided from the other post he sets things up to run some sample tests via PHPUnit. He makes a simple DTrace D script to configure a tracer to watch for "function entry" and "function exit" during execution, outputting the function tree each time when the given function is found (via a parameter). He includes both the command to run the test with the trace and an example of the output result.