[M3commit] CVS Update: cm3

[Antony Hosking]

CVSROOT:	/usr/cvs
Changes by:	hosking at birch.	07/06/02 21:15:24

Modified files:
	cm3/m3-libs/m3core/src/runtime/common/: RT0.i3 RTCollector.m3 
	                                        RTHeapEvent.i3 
	                                        RTHeapRep.i3 

Log message:
	Use much more fine-grained read and write barriers:
	- read barrier needs only to check that object reference being loaded is not
	gray, cleaning just that one object if it is.
	- write barrier needs only to check that object is not dirty, marking that one
	object if its, and setting the page to dirty as well if it is not already.
	
	These changes pave the way for ultimate deletion of the "protected" page-level
	descriptor bit, as well as elimination of all the virtual-memory protection
	cruft which is now obsolete.  This will make for a much more maintainable and
	malleable GC subsystem.