I have actually used one java library in python multithread. Ie the java call timedout and i tried to create a new instance (the timeout was not properly implemented and java was still running). So i created new instance and saw two instances of java object taking both cpus. I thought it is a nice side effect. I havent done anything with it (it was a mistake) but worth trying. In this case gil is actually a benefit. Right?
On 3/6/10, Bill Janssen <jans...@parc.com> wrote: > Andi Vajda <va...@apache.org> wrote: > >> >> On Mar 5, 2010, at 13:48, Bill Janssen <jans...@parc.com> wrote: >> >> > The problem Python has with multiple cores and multi-threading, >> > pointed >> > out by Dave Beazley last year (http://www.dabeaz.com/python/GIL.pdf), >> > looks like it will still persist for the next three or four years, at >> > least, on OS X. Incredible but true. I'm presuming that PyLucene >> > also >> > suffers from it, though the interaction with Java threads makes me >> > wonder a bit. >> > >> > Anyone know whether this is so? >> >> Any thread that enters java releases the GIL. When the execution >> returns (or enters) python again, the GIL is reacquired. >> >> In other words, the answer to your question depends on how much time >> your threads are spending in the JVM. > > So, yes, that Python will still suffer from the issue if it has lots of > CPU-bound threads fighting to get scheduled, but time spent in the JVM > counts as I/O time, not computation time. OK, that's useful. > >> > And, a follow-up question: if one were to build a version of Python >> > 2.6 >> > with the "newgil" patch in http://bugs.python.org/issue7753 applied, >> > would it break jcc? >> >> If the GIL and threading APIs didn't change I wouldn't expect any >> issues. > > The whole point of that patch is to backport Antoine Pitrou's new GIL > from Python 3.2 to Python 2.5 - 2.7. See > http://www.dabeaz.com/python/NewGIL.pdf for an overview. So the GIL > changes. But perhaps not in a way that affects jcc. > > Bill > -- Sent from Gmail for mobile | mobile.google.com
