js_flow.d - snoop JavaScript execution showing function flow using DTrace. js_flow.d This traces activity from all browsers on the system that are running with JavaScript provider support. Filename and function names are printed if available. Any Evolving - uses the DTrace JavaScript provider, which may change as additional features are introduced. Check JavaScript/Readme to see what version these scripts are based on.

Default output, # js_flow.d

C CPU-id

TIME(us) Time since boot, us

FILE Filename that this function belongs to

FUNC Function name

-> function entry

<- function return

Watch the first column carefully, it prints the CPU-id. If it changes, then it is very likely that the output has been shuffled.

See the DTraceToolkit for further documentation under the Examples, Notes and Docs directories. The example files may be especially useful as they aim to demonstrate how to interpret the output. js_flow.d will run until Ctrl-C is hit. Brendan Gregg [CA, USA] dtrace(1M)