Comments on: trying to grok greenlets – more experiments in concurrent programming http://www.rhonabwy.com/wp/2007/12/01/trying-to-grok-greenlets-more-experiments-in-concurrent-programming/ Mac OS X, iPhone, Tech, and daily life in Seattle Fri, 12 Mar 2010 14:22:44 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: denis http://www.rhonabwy.com/wp/2007/12/01/trying-to-grok-greenlets-more-experiments-in-concurrent-programming/comment-page-1/#comment-86194 denis Wed, 04 Mar 2009 08:13:30 +0000 http://www.rhonabwy.com/wp/2007/12/01/trying-to-grok-greenlets-more-experiments-in-concurrent-programming/#comment-86194 why it does not work is because Queue and greenlets aren't designed to work together. All your greenlets, in fact, run in the same thread, so when messageQueue.get() blocks because the queue is empty it blocks every other greenlet you have, giving your program no chance to put something in the queue. in eventlet, there's coros.queue that works as expected. however, with eventlet, you don't create greenlets directly and switch() between them, instead you spawn() them (which is quite easy) and use communication primitives provided by eventlet, classes like coros.queue, coros.event. and btw, use this eventlet http://devel.ag-projects.com/~denis/cgi-bin/hgweb.cgi it's the most stable eventlet available at this point. why it does not work is because Queue and greenlets aren’t designed to work together.
All your greenlets, in fact, run in the same thread, so when messageQueue.get() blocks
because the queue is empty it blocks every other greenlet you have, giving your program
no chance to put something in the queue.

in eventlet, there’s coros.queue that works as expected. however, with eventlet, you don’t create greenlets
directly and switch() between them, instead you spawn() them (which is quite easy) and use
communication primitives provided by eventlet, classes like coros.queue, coros.event.

and btw, use this eventlet
http://devel.ag-projects.com/~denis/cgi-bin/hgweb.cgi
it’s the most stable eventlet available at this point.

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