From: Logan Capaldo <logancapaldo@...>
Date: 2006-02-24T08:20:56+09:00
Subject: Re: Launching Ruby scripts and the future of MVM


On Feb 23, 2006, at 5:42 PM, gwtmp01@mac.com wrote:

>
> On Feb 23, 2006, at 5:05 PM, Charles O Nutter wrote:
>> I tossed this message off to the Ruby-core list about a month ago,  
>> and
>> sent a follow-up email today. The basic idea is that if there were a
>> Kernel#run_script method or similar, all Ruby apps that want to  
>> launch
>> external scripts could do so in a platform and
>> implementation-independent way.
>
> In what way is what you are proposing different from Kernel#system?
>
> Gary Wright
>
>
>
>

system(x) # x is arbitrary shell command
run_script(x) # x is guaranteed to be a script written in ruby

This means for instance, that run_script could get away with not  
forking a new process, but rather just a new ruby VM assuming that  
the ruby implementation had that capability
  In the OPs example, using system to run another ruby script is  
going to cause a whole new JVM to be created, along with the overhead  
of a new ruby interpreter.  Apparently JRuby has the ability to have  
multiple instances of ruby per process. By incorporating this method  
into ruby, scripts that want to run other ruby scripts can run faster  
than they do currently (and no slower). In the C implementation of  
ruby of course run_script could easily be implemented in terms of  
system, but the JRuby guys would be able to implement it in a more  
performant manner for their situation. Likewise YARV could  
theoretically create a new instance of itself instead of a whole  
nother process.