From: James Edward Gray II <james@...>
Date: 2005-11-17T00:22:33+09:00
Subject: Re: DRb Crashing

On Nov 15, 2005, at 6:50 PM, Hugh Sasse wrote:

> On Wed, 16 Nov 2005, James Edward Gray II wrote:
>
>
>> If I launch this server:
>>
>         [...]
>
>> __END__
>>
>> Then run this client:
>>
>> #!/usr/local/bin/ruby -w
>>
>> require "drb"
>> require "rinda/tuplespace"
>>
>> DRb.start_service
>> tuplespace = Rinda::TupleSpaceProxy.new(
>>  DRbObject.new_with_uri("druby://localhost:61676")
>> )
>>
>> while problem = tuplespace.take(["Problem", %r{^\d+(?: [-+*/] \d+)+ 
>> $}])
>>  tuplespace.write(["Result", "#{problem.last} = #{eval  
>> problem.last}"])
>> end
>>
>> __END__
>>
>> The client crashes, generally within a few seconds.  Adding a  
>> sleep inside the
>> server loop seems to resolve the issue.
>>
>> Anyone know why?
>>
>
> No, I don't. What happens if you match the old way? Like:
>   while problem = tuplespace.take(["Problem", nil])

The Regexp is pretty critical in this case.  It validates the data  
before an otherwise dangerous call to eval().

James Edward Gray II