Race condition in DRb: Socket not always closed in DRb.stop_service
-------------------------------------------------------------------
Key: JRUBY-2347
URL: http://jira.codehaus.org/browse/JRUBY-2347
Project: JRuby
Issue Type: Bug
Components: Core Classes/Modules
Affects Versions: JRuby 1.1
Environment: Latest JRuby 1.1 from trunk.
Reporter: Vladimir Sizikov
The following example:
{noformat}
require 'drb'
5.times {
DRb.start_service('druby://localhost:9001')
DRb.stop_service
}
{noformat}
Produces the following exception in JRuby:
/opt/work/jruby.git/lib/ruby/1.8/drb/drb.rb:865:in `new': Address already in
use - Address in use (Errno::EADDRINUSE)
from /opt/work/jruby.git/lib/ruby/1.8/drb/drb.rb:865:in `open'
from /opt/work/jruby.git/lib/ruby/1.8/drb/drb.rb:865:in `open_server'
from /opt/work/jruby.git/lib/ruby/1.8/drb/drb.rb:759:in `open_server'
from /opt/work/jruby.git/lib/ruby/1.8/drb/drb.rb:757:in `each'
from /opt/work/jruby.git/lib/ruby/1.8/drb/drb.rb:757:in `open_server'
from /opt/work/jruby.git/lib/ruby/1.8/drb/drb.rb:1339:in `initialize'
from /opt/work/jruby.git/lib/ruby/1.8/drb/drb.rb:1628:in `new'
from /opt/work/jruby.git/lib/ruby/1.8/drb/drb.rb:1628:in `start_service'
from test-drb.rb:4
from test-drb.rb:3:in `times'
from test-drb.rb:3
After some investigation it seems that the flaw is in the DRb itself, and simple
addition of sleep 1 in lib/ruby/1.8/drb/drb.rb, in method run (line 1428),
leads to the same exception even in MRI.
Basically, a new Thread is being started in the run method, it has begin-ensure
block, but in case when a thread is started but not yet entered begin-ensure,
an attempt to stop the service and to kill the thread leads to situation when
ensure block is not executed, and the following satement is not being run:
@protocol.close if @protocol
Hence, the port is not being freed.
This leads to some rubyspec failures, since the specs exhibit exactly this
behavior, starting and stopping the DRb service quickly.
--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
http://jira.codehaus.org/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
---------------------------------------------------------------------
To unsubscribe from this list, please visit:
http://xircles.codehaus.org/manage_email
