gprof profiling of multi-threaded Cygwin programs

Jon Turney jon.turney@dronecode.org.uk
Thu Feb 18 10:59:00 GMT 2016


Thanks for this.

On 17/02/2016 05:28, Mark Geisert wrote:
> There is a behavioral change that ought to be documented somewhere:  If
> a gmon.out file exists when a profiled application exits, the app will
> now dump its profiling info into another file gmon.outXXXXXX where
> mkstemp() replaces the Xs with random alphanumerics.  I added this
> functionality to allow a profiled program to fork() yet retain profiling
> info for both parent and child.  The old behavior was to simply
> overwrite any existing gmon.out file.

Did you consider making the filename deterministic (e.g. based on pid or 
such) rather than random?

With a random filename, if you have a process which forks more than 
once, working out which gmon.out* file corresponds to which process 
could be tricky.

A brief search tells me that apparently glibc supports the 
(undocumented) GMON_OUT_PREFIX env var which enables a similar behaviour.



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