[Boost-users] System call to get current process memory usage?

What if any system calls exist to get the current process' system memory usage (including all of the current process' threads)? I'm trying to write unit tests to make sure that my memory allocation processes (for Boost "smart pointers) are actually deallocating correctly after thousands of dynamic allocations...and my presumption is that a process-memory "self check" thoughout this process will be very useful for my self-running unit test. I'd prefer cross-platform calls (be it POSIX, unix/linux, Boost C++, etc...preferably not win32-specific if I can avoid it, but if I must I will) if I can get them, but I'll take a system specific all (for my testing prototype) if I must. Thanks for any help, -Matt