From: "Sandor Szücs" <sandor.szuecs@...>
Date: 2009-05-09T21:32:20+09:00
Subject: Re: Thread and Mutex in Ruby 1.8.7


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


hth. Sandor Szücs
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