No. 99 (00222)

Family name : Taylor
Given name : Lucas
Affiliation : Northeastern University
Abbreviation : CMS
E-mail address : Lucas.Taylor@cern.ch
Title : A Coherent Environment of Software Improvement Tools for CMS
Authors : Lucas Taylor, on behalf of the CMS Collaboration
Abstract : 
CMS has developed approximately one million lines of C++ code and uses
many more from HEP, Grid and public domain projects.  We describe a
suite of tools which help to manage this complexity by measuring
software dependencies, quality metrics, and CPU and memory
performance.  This coherent environment integrates and extends
existing open-source tools where possible and provides new in-house
components where a suitable solution does not already exist.

This is a freely available environment with graphical user interface
which can be run on any software without the need to recompile or
instrument it.  We have developed Ignominy which performs software
dependency analysis of source code, binary products and external
software.  CPU profiling is provided based on oprofile, with added
features such as profile snapshots, distributed profiling and
aggregate profiles for farm systems including server-side tools for
collecting profile data.  Finally, we have developed a low-overhead
performance and memory profiling tool, MemProf, which can perform
(gprof-style) hierarchical performance profiling, in a way that works
with multiple threads and dynamically loaded libraries (unlike gprof).
It also gathers exact memory allocation profiles including which code
allocates most, in what sizes of chunks, for how long, where the
memory is getting freed and where it is getting leaked.

We describe this tool suite and how it has been used to enhance the
quality of CMS software.