[Python-Dev] C API for gc.enable() and gc.disable() (original) (raw)

Greg Ewing greg.ewing at canterbury.ac.nz
Fri Jun 27 02:11:00 CEST 2008

Jeff Hall wrote:

I mistakenly thought that was because they were assumed to be small. It sounds like they're ignored because they're automatically collected and so they SHOULD be ignored for object garbage collection.

Strings aren't tracked by the cyclic garbage collector because they don't contain object references and therefore can't form part of a cycle.

However, unless I'm mistaken, allocations and deallocations of them are still counted for the purpose of determining when to perform a cyclic GC pass. So if you allocate lots of strings and they aren't getting deallocated, a cyclic GC pass will eventually occur, in case the strings are being referenced from a cycle that can be cleaned up.

I don't know whether/how re uses string objects internally while it's matching, so I can't say what its garbage collection characteristics might be when matching against a huge string.

The behaviour you observed might have been due to the nature of the re being matched -- some res can have quadratic or exponential behaviour all by themselves.

-- Greg

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