From: Mike Bethany <mikbe.tk@...>
Date: 2011-06-18T08:19:37+09:00
Subject: Re: Threadsafing a mixin module without using self.new or initialize.

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On Fri, Jun 17, 2011 at 5:45 PM, Robert Klemme
<shortcutter@googlemail.com>wrote:


> Since this is a mixin module I can't use initialize to create the mutex
>> instance variable
>>
>
> Why not?
>
> module Anything
>  def initialize(*a,&b)
>    super
>    @lock = Mutex.new
>    @data = []
>  end
> end
>
> class Other
>  include Anything
>
>  def initialize
>    super # important!
>    @another_var = 15
>  end
> end
>
>
[smacks forehead] Doh! I'm still learning Ruby, didn't even think about
that. I like the initialize method MUCH better. If they forget to include
the super it'll raise an exception when they go to use it so I just need to
make sure I document and emphasize that fact really well.



> That approach does not scale well if you have lots of instances created
> concurrently.  If anything fails you can add a method which creates the
> mutex and which is called before the instance is used by multiple threads -
> as simple as that.  But I'd prefer the approach with #initialize.
>

Yeah, I thought about that and it was why I didn't really like my solution.
Limiting creation at the class level could be a major bottleneck. Plus it
just felt hackey; but not in a good way.


> Kind regards
>
>        robert
>
> --
> remember.guy do |as, often| as.you_can - without end
> http://blog.rubybestpractices.**com/ <http://blog.rubybestpractices.com/>


Thanks for the help!

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