From: Masatoshi SEKI <m_seki@...>
Date: 2000-10-28T01:41:50+09:00
Subject: [ruby-talk:5926] Re: [RFC] Towards a new synchronisation primitive


Hi,

I worte too Mutex Mix-in "MutexM". (see [ruby-list:23787])

  [RAA:MutexM] --> http://www.ruby-lang.org/en/raa-list.rhtml?name=MutexM



MutexM futures:
  * Mix-in class

  * reentrant synchronize

  * synchronized():
    define synchronized method

  * synchronize_reader, synchronize_writer, synchronize_accessor:
    define synchronized attr_reader/writer/accessor

  * in_synchronize
    raise ThreadError unless locked?


Sample code:
  class Foo
    include MutexM

    def initialize
      super
      @foo = nil
      @bar = nil
      @count = 0
    end
    synchronize_accessor(:foo)	# synchronized accessor
    lock_accessor("bar")	# accessor that raise ThredError unless locked?

    def commit
      in_synchronize		# raise ThreadError unless locked?
      p [@foo, @bar]
    end

    def sleep_and_set	    	# 
      sleep 0.5
      @foo = @foo + @foo
      sleep 0.5
      @bar = @bar + @foo
      [@foo, @bar]
    end

    synchronized :sleep_and_set	# define synchronized method
  end

  f = Foo.new
  f.foo = 1
  p f
  f.synchronize do 
    f.foo = 3		# reentrant synchronize
    f.bar = 2	
    f.commit
  end
  p f
  begin
    f.bar = 4		# raise ThreadError
  rescue ThreadError
    p $!
  end
  p f

  Thread.new do
    p f.sleep_and_set	# synchronized
  end
  sleep 0.2
  f.foo = 5

  sleep 2
  p f



From: Robert Feldt <feldt@ce.chalmers.se>
Subject: [ruby-talk:5916] Re: [RFC] Towards a new synchronisation primitive
Date: Fri, 27 Oct 2000 23:40:50 +0900

> Below is example code for Mutex and module Synchronized (using
> test_and_set), using test_and_set, so that you can do:
>     
> class MySynchedClass
>   include Synchronized
>   def my_synched_method
>     ...
>   end
>   synchronized :my_synched_method
> end
     
> It's only on the object level though. Finer granularity might be needed...
> 
> I think it correctly handles Dave's RingBuffer example but I'm not
> sure. Can someone verify?
> 
> class Mutex