Re: load and use a ".o" file?

[Mark H Johnson <Mark_H_Johnson@raytheon.com>]

lifetime n00b wrote:

> Mark H Johnson wrote:
> 
>>  - call xyz (dispatched to an activation function)
>>  - the activation function checks first the active segments for a 
>> symbol within them called xyz. If found, it fixes up the dispatch to 
>> go directly to that xyz and resumes execution.
>>  - if not in an active segment, it uses the search path (similar to 
>> PATH on Unix) to find a file named xyz. If found, it loads that file 
>> into a segment, makes it active, and does the work of the second step.
>>  - if no such file is found, it calls the command line interpreter 
>> with an error status. 
> 
> 
> This actually sounds a lot like using a distributed system (Annex E) 
> with both active and passive partitions on the same local machine, 
> though probably more efficient.
> 
No, they were actually subroutine calls. The compiler generated slightly 
different code for an "in segment" call and a "cross segment" call due 
to the indirection. The glue code (to do the lookup) was basically a 
system service done by the OS to facilitate activation of new segments.

By the way, when I say segment - I mean a segment of the same address 
space, not a partition. Think to the 386 processor where you have 32 k 
segments in certain processing modes. On Multics, the segments were 256 
Kwords (1 Mbyte) in size which worked quite well in practice.
   --Mark