Need an API to set the directory for trace files on the fly (immediately prior to trace_on) - transferred issue from gitlab

[utke1]

My use case is a multi-process parallel task each of which runs several derivative computations (gradient, Jacobian, etc.). Therefore the traces need to be differentiated by process AND by task (i.e. gradient, Jacobian etc.). Even if I assumed that I could use the process ID to distinguish traces between the processes, then the current type for the trace tag does not provide sufficient values to also distinguish by task inside each process. So, I would rather take a constant tag for each trace associated with a given process process but place them in a subdirectory named by process ID e.g. /tmp/traces_
Hence the request for such an interface to set the directory name.

This was copied from gitlab where the issue had been opened on March 17, 2016

[utke1]

Regarding the follow-up question from @kkulshre :

Is this a mix of MPI and OpenMP? Could you provide more information about the use case? What about traces that stay in core, and don't go to disk? We probably need some kind of namespacing for those as well, which isn't quite straightforward.

this is driven by python multiprocessing