Is there a way to know how much memory is currently allocated?

[Yuri]

Does FreeBSD malloc library provide any API way to know how many bytes 
are currently allocated by the current process?
Memory image size isn't adequate, since it's always much larger because 
of various reasons, like an extra-memory allocated for the needs of 
malloc library itself an also due to non-freed blocks, which are left 
allocated by the library.

Yuri