[Python-ideas] Concurrent refcounting research

Jason Orendorff jason.orendorff at gmail.com
Tue Oct 16 20:56:27 CEST 2007

GIL-slayers take note.  Here are two papers about concurrent reference counting:

    An On-The-Fly Reference Counting Garbage Collector for Java
    Levanoni and Petrank, 2001.

    Efficient On-the-Fly Cycle Collection
    Paz, Bacon, Kolodner, Petrank, and Rajan, 2005.

"On-the-fly" means the algorithm is neither "fully concurrent" nor
"stop the world".  Rather, each thread pauses occasionally to do some
work.  Instead of a GIL, you have a lock that covers this periodic

The details are awfully complex, but there may be insights worth
gleaning regardless.

Also -- I wrote some stuff at:
in the hopes that future "Kill GIL" discussions can start from a
better-informed base.


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