From: "rklemme (Robert Klemme)" <shortcutter@...>
Date: 2012-09-30T01:32:45+09:00
Subject: [ruby-core:47740] [ruby-trunk - Bug #7087] ::ConditionVariable#wait does not work with Monitor because Monitor#sleep does not exist


Issue #7087 has been updated by rklemme (Robert Klemme).


kosaki (Motohiro KOSAKI) wrote:
> At least, this is intentional. condtion variable and monitor have different inspiration source.
> condition variable is based on POSIX CV and monitor is based on Java monitor semantics. To be
> honest, I'm not familiar Java's conditon variable.

For me the difference between Mutex and Monitor is only reentrancy.  Other than that I'd have expected them to be identical (usage and interface).

> Could you please explain the detail of your
> suggestion? Which semantics do you hope?

I would have expected that I can use a Monitor / instance which includes MonitorMixin the same way as a Mutex with ::ConditionVariable.  If that is not intended then I'd rather have an exception TypeError from ::ConditionVariable#wait indicating that a Mutex must be used than the exception about the private sleep method (which happens to be the one from Kernel).
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Bug #7087: ::ConditionVariable#wait does not work with Monitor because Monitor#sleep does not exist
https://bugs.ruby-lang.org/issues/7087#change-29794

Author: rklemme (Robert Klemme)
Status: Open
Priority: Low
Assignee: 
Category: 
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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