PHP xDebug graph interpretation

Question

I am profiling a PHP application (built upon the Zend framework). Attached you can find a screenshot of the main call graph that KCacheGrind produces from xDebug output.

There are two things that I don't understand:

1) Why does {main} "fork" into 2 calls? Are they supposed to be parallel somehow or does one happen after the other?

2) The arrow to the left of {main} has a little blue bar with the text 2x; does this mean that the call to Zend_Application->bootstrap happened twice?

 

Answer 1

1. The calls (of course) happen after each other. The graph splits because each of the top two functions are called by main(). The graph shows calls, not execution order.

2. Yes, that's exactly what it means. main() called Zend_Application->bootstrap twice and ->run once.