[capi-sig] is deinitialisation of embedded python equal to fullrestart?

Hrvoje Niksic hniksic at xemacs.org
Fri Jul 13 12:29:48 CEST 2007

Alexey Nezhdanov <snakeru at gmail.com> writes:

> The most essential for me is freeing all sorts of RAM that python allocated 
> for objects or whatever else.

Reinitializing Python should work, but it might not produce the effect
you expect.

Python allocates memory using the underlying C functions such as
malloc.  Shutting down the interpreter simply makes Python call free
on the memory segments that belong to Python objects.  Because of the
way malloc and free work, doing that is no guarantee that memory will
be returned to the operating system.  free() only guarantees that the
memory will be marked as usable for unspecified later calls to malloc.
Some malloc implementations go one step further and actually return
the memory to the system, but that is only possible when freeing the
block(s) at the very end of the region, so you cannot rely on it.

At the end of the day, your process will probably not decrease in
memory footprint; however, it will not grow on further allocations
because it will reuse the freed memory.  But, barring a bug in Python,
that is exactly the situation you would be in if you didn't
reinitialize the interpreter in the first place.

> IOW - I want python to be returned in virgin state as it was on my
> program load w/o exiting my program and closing all files/tcp
> connections that it have opened/or resetting any of other my C data
> structures that were created.

Doesn't Python automatically close open files when the script

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