Moving towards Python 3.0 (was Re: [Python-Dev] Speed up function calls) (original) (raw)

"Martin v. Löwis" martin at v.loewis.de
Mon Jan 31 20:21:10 CET 2005

Evan Jones wrote:

The next page has a micro-benchmark that shows reference counting performing very poorly. Not to mention that Python has a garbage collector anyway, so wouldn't it make sense to get rid of the reference counting?

It's not clear what these numbers exactly mean, but I don't believe them. With the Python GIL, the increments/decrements don't have to be atomic, which already helps in a multiprocessor system (as you don't need a buslock). The actual costs of GC occur when a collection happens - and it should always be possible to construct cases where the collection needs longer, because it has to look at so much memory.

I like reference counting because of its predictability. I deliberately do

data = open(filename).read()

without having to worry about closing the file - just because reference counting does it for me. I guess a lot of code will break when you drop refcounting - perhaps unless an fopen failure will trigger a GC.

Regards, Martin

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