Shared system routines

[barmar at mit-eddie.UUCP]

The discussion of shared libraries that occurred a while ago was 
mostly about whether library routines that just about everyone
uses should be moved into the kernal, since people didn't want
to have to deal with these issues.  It died, luckily.

BTW, shared libraries were implemented in Multics (a "pre-clone" of
Unix :-)) from day 1 (nearly twenty years ago).  We call it dynamic
linking, and I wouldn't want to live without it.  All it takes
is a bit in indirect pointers which causes a reference to fault;
the OS traps the linkage fault, unfaults the pointer to find the
symbolic name of the reference, finds the library routine, patches
the indirect pointer to reference it, and restart the instruction.
-- 
			Barry Margolin
			ARPA: barmar at MIT-Multics
			UUCP: ..!genrad!mit-eddie!barmar