From: "headius (Charles Nutter)" <headius@...>
Date: 2012-10-23T00:55:57+09:00
Subject: [ruby-core:48151] [ruby-trunk - Bug #7087] ::ConditionVariable#wait does not work with Monitor because Monitor#sleep does not exist


Issue #7087 has been updated by headius (Charles Nutter).


A few JRuby tidbits that might help shed some light.

Java's per-object monitors are reentrant, as already stated. They do not, however, provide a mechanism for querying who has locked, how many are waiting, etc. Because of that, JRuby implements Mutex using ReentrantLock and just ensures the same thread cannot lock the same Mutex twice:

https://github.com/jruby/jruby/blob/master/src/org/jruby/ext/thread/Mutex.java

The standard 'thread' library ConditionVariable is implemented atop Mutex, as in Ruby: https://github.com/jruby/jruby/blob/master/src/org/jruby/ext/thread/ConditionVariable.java

And we use the same monitor.rb as 1.9.3.
----------------------------------------
Bug #7087: ::ConditionVariable#wait does not work with Monitor because Monitor#sleep does not exist
https://bugs.ruby-lang.org/issues/7087#change-31226

Author: rklemme (Robert Klemme)
Status: Open
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: lib
Target version: 
ruby -v: ruby 1.9.3p194 (2012-04-20) [i686-linux]


See program attached to bug #7086: timeout_4 always throws:

ERROR: method "timeout_4": #<NoMethodError: private method `sleep' called for #<Monitor:0x87e49f8>>

$ irb19 -r monitor
irb(main):001:0> Monitor.new.method(:sleep)
=> #<Method: Monitor(Kernel)#sleep>
irb(main):002:0> Monitor.instance_methods.grep /sleep/
=> []


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