From: Robert Klemme <shortcutter@...>
Date: 2009-05-10T21:10:05+09:00
Subject: Re: Thread and Mutex in Ruby 1.8.7

On 09.05.2009 14:32, Sandor Szücs wrote:
> On 05.05.2009, at 14:35, Guillaume Gdo wrote:
> 
>> mutex=Mutex.new
>> mutex.synchronize do
>>   mutex.synchronize do
>>     puts "A"
>>     puts "B"
>>   end
>> end
> 
> Mutex is not reentrant.
> 
> irb> m=Mutex.new
> irb> m.synchronize do
> irb>  puts "foo"
> irb>  m.synchronize do
> irb>   puts "bar"
> irb>  end
> irb> end
> foo
> ThreadError: thread 0x341ac tried to join itself
>          from (irb):4:in `synchronize'
>          from (irb):4
>          from (irb):2:in `synchronize'
>          from (irb):2
> 
> 
>> Nevertheless my thread have a lock on the mutex. How to reuse it ?
> 
> 
> Use Monitor instead of Mutex.
> 
> irb> m=Monitor.new
> irb> m.synchronize do
> irb>   puts "foo"
> irb>   m.synchronize do
> irb>    puts "reentrant"
> irb>   end
> irb> end
> foo
> reentrant

And then there is also MonitorMixin which adds monitor functionality to 
every class or instance.

Kind regards

	robert


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