Help on SAPI and TSRM ?

Hi there, I'm trying to write a "C++ Wrapper", so it's possible for me to execute PHP code from my own C++ programms. I used the CLI-SAPI (php4/sapi/cli/...) as a template for my "C++ Wrapper". This works fine if the calling application is a single process but I run into trouble if I call PHP (run PHP code) from threads. Could anybody give a quick overview on TSRM or tell me where to find some documentation (I couldn't find any) ? I'm especially interested in : How to call PHP from threads and how to access the result of the PHP run from different threads ? Thanks !