[gclist] GC points and GC map

Okehee Goh ogoh@asu.edu
Fri, 07 Feb 2003 09:33:45 -0700

 I'm not sure whether this list is active enough to post questions. If not,
please take my apology.
 I have questions regarding GC map and GC points to implement Exact GC( not
conservative GC).

 When I read the paper[2], there seem GC points that can tolerate GC.
Despite not considering exact GC, still there are some points which can't
tolerate GC on multi-threaded system?
 According to the paper [1] ( or [2]), in order to implement Exact GC, it
seems to need to place GC points on some instructions that generate GC map
(or stack map -- contains a set of registers and stack locations that refer
to live objects in heap)
 So, GC points and GC map are just necessary to support Exact GC? Otherwise,
it is also relevant to implement incremental GC?

 Actually I'm trying to design incremental GC which shows deterministic
behavior on multi-threaded system of single processor. It mean that one
thread runs at a time. Sill there are some points that can't tolerate GC
when GC thread tries to run by preempting other work threads?

 I appreciate any opinion. ( Forgive if this question is too basic)



[1]Ole Agesen. GC Points in a Threaded Environment. SMLI TR-98-70. Sun
Microsystems, Palo Alto, CA, December 1998.
[2] http://wwws.sun.com/software/communitysource/j2me/cdc/
[3] J. M. Stichnoth, G.-Y. Lueh, and M. Cierniak. Support for Garbage
Collection at Every Instruction in a Java Compiler. Proceedings of the ACM
Conference on Programming Language Design and Implementation, May 1999, pp.

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