[Boost-build] BJam parallel support

From: Alex Besogonov (cyberax_at_[hidden])
Date: 2006-05-15 00:40:30

I'm thinking to add parallel execution support to BJam other than 
parallel actions execution.

Something like this:
===================
...
process_id = [ FORK ] ;
if process_id = 0
{
        #We're inside the child process
        TELL [ GET_PARENT ] : "Hello, world!" ;
        EXIT 0 ;
} else
{
        #We're still inside the parent
        WAIT_FOR $(process_id) ;
        message = [ GET_MESSAGE $(process_id) ] ;
        ECHO $(message) ; #Should print 'Hello, world!'
}
...
===================
All 'forking' will be done logically inside the interpreter, so no 
support from operating system will be necessary (threads/vfork will be 
used in case they are available).

I think it can be useful to do building while constructing dependency 
graph at the same time.

Any thoughts?

-- 
With respect,
             Alex Besogonov (cyberax_at_[hidden])