From: Eric Wong <normalperson@...>
Date: 2011-09-11T09:30:15+09:00
Subject: [ruby-core:39457] [Ruby 1.9 - Bug #5306] Application Hangs Due to Recent rb_thread_select Changes


Issue #5306 has been updated by Eric Wong.

File 0001-thread.c-rb_thread_select-mark-original-fd_sets-prop.patch added

Thanks for the straces, I was able to tell the EM pipe was stuck on a
false-positive and calling a blocking read() on a pipe that had no data.

Attached is a patch which should fix the issue, sorry for the bug :x

----------------------------------------
Bug #5306: Application Hangs Due to Recent rb_thread_select Changes
http://redmine.ruby-lang.org/issues/5306

Author: Charlie Savage
Status: Open
Priority: High
Assignee: 
Category: core
Target version: 1.9.3
ruby -v: ruby 1.9.3dev (2011-09-09 revision 33236) [x86_64-linux]


This commit:

4e9438bc9153f7a1f4ea0af85c8dbe359e1a55d8

Changed the implementation of rb_thread_select.  

It causes eventmachine to hang on CentOS 5.5.  Not sure what the issue is, but its easily reproduced by by running the test eventmachine/tests/test_epoll.rb.  

We noticed this because it also causes the tweetstream gem to hang.

The same setup works on Fedora 14 and an up-to-date arch linux.  Specific version information included below.

We temporarily fixed this by reverting the commit.

Since Centos is a common production environment (and the one we are using), this seems to us a blocker for 1.9.3. 

We are happy to provide any additional information or test fixes.  

Thanks - Charlie

--------------
We are running this version of CentOS:

Linux app1.zerista.com 2.6.18-238.19.1.el5.centos.plus #1 SMP Mon Jul 18 10:05:09 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux

And this version of Fedora:

Linux ammonite.internal.zerista.com 2.6.35.14-95.fc14.x86_64 #1 SMP Tue Aug 16 21:01:58 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

And this version of eventmachine:

eventmachine (1.0.0.beta.3)

And this version of tweetstream:

tweetstream (1.0.4)


-- 
http://redmine.ruby-lang.org