determine slight info programmatically darwin/osx

i have category following member functions:

/// traveller pid
virtual pid_t pid() const = 0; 

/// physical memory distance kb
virtual uint64_t size() const = 0;  

/// renter memory process
virtual uint64_t rss() const = 0; 

/// cpu used process
virtual double percentcpu() const = 0; 

/// memory used process
virtual double percentmemory() const = 0; 

/// array threads process
virtual int32_t lwps() const = 0; 

this class' calling relapse slight information caller. physical memory distance simply dynamic sysctl call, pid trivial, nonetheless remaining calls have eluded me, aside invoking popen ps tip parsing cost - isn't acceptable. any assistance severely appreciated.

requirements:

compiles g++ 4.0

no obj-c

osx 10.5