Profiling

Profiling

DMD comes with an option to instrument an executable for profiling its execution. You can enable it on the project configuration page "Code Generation".

Image(source:wiki/prop_codegen.png)

Running the executable will create a file named trace.log in the current working directory. Opening the profiler window from the Visual D menu allows browsing the info in this file conveniently. You must specify the full path to the trace.log in the edit field at the top of the window.

Image(source:wiki/profiler.png)

The toolbar at the top is used to

 - enable/disable alternate color display for the rows
 - enable/disable automatic closing of the profiler window if you jump to a function by double-clicking its list entry
 - enable/disable display of full type information of the functions
 - enable/disable display of function fan in/out, i.e. which functions are called by the selected function and which functions are calling it
 - guess the location of the trace.log file from the current startup project and its debugging settings
 - remove the trace.log file from disk to start a new profiling session (without removing the file multiple runs of the executable accumulate statistics in the log file)
 - refresh display from the trace.log file

The times in the function list are displayed in microseconds.

 - Tree time: time spent executing the function including functions called
 - Func time: time spent executing the function excluding functions called
 - Call time: Func time/Calls

Double-clicking a line in the function list tries to jump to the corresponding source code line. This relies on appropriate information found in generated JSON files.

Double clicking a line in the caller/callee lists selects the function in the function list, so you can navigate through the call tree.