Russell Fulton wrote:
> Is there a way to ensure that a particular variable really is local
> to a thread block?  I have a problem with a threaded program that
> would be explained if one of the local variable was actually global.
> I've checked everything I can think of...
>
> I miss my and local from perl which allowed me to explicitly control
> the scope of variables.

A typical problem with threads can be nicely illustrated with this:

09:21:51 [~]: ruby -e 'th=[]
> for i in 0 .. 5
>   th << Thread.new do
>     sleep(rand(5))
>     puts i
>   end
> end
> th.each {|t| t.join}
> '
2
5
5
5
5
5
09:22:21 [~]:


Problem here is that all threads share the local var 'i'.  Solution:

09:22:21 [~]: ruby -e 'th=[]
> for i in 0 .. 5
>   th << Thread.new(i) do |x|
>     sleep(rand(5))
>     puts x
>   end
> end
> th.each {|t| t.join}'
0
1
5
4
2
3

I.e. provide value(s) as arguments to Thread.new and receive them as block
parameter(s) with different name(s).

HTH

Kind regards

    robert