A sampling process monitor for Cygwin
This project is an experiment in profiling by IP (instruction pointer) sampling. Cygwin already has a built-in profiler (accessed through gcc's -pg compiler option), but it has limitations. One limitation is an inability to record samples for dynamically linked libraries. Another limitation is that the program that processes profiler data files, gprof, does not currently support symbol tables from more than one image at a time (such as dynamic library symbols in addition to a program's symbols). There is nothing Cygwin-specific about these limitations; Linux profilers have the same limitations.
cygmon avoids these limitations by being able to sample multiple text segments and by writing multiple gmon.out files, one for the program and one for each dynamic library that had samples recorded. cygmon can also sample child processes forked from the initially profiled process.
Interim build instructions: This project assumes you are already set up to build the Cygwin DLL. In your Cygwin source tree, navigate to the winsup/utils directory. Copy cygmon.cc from this project into that directory. Merge (carefully) the contents of mingw/Makefile.am from this project into the version in winsup/utils/mingw. The effect of the merge is to add cygmon to the list of utilities built as Windows native programs (like strace and dumper) rather than as Cygwin programs. Navigate to the corresponding build location and run make. That will create a cygmon.exe that you can place in /usr/local/bin, for instance.
Note that this is the final beta release for testing by anybody interested.