harmony-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Xiao-Feng Li" <xiaofeng...@gmail.com>
Subject [DRLVM][JIT] write barrier broken by new jit opts?
Date Sun, 07 Jan 2007 05:59:19 GMT
Hi, I found write barrier in DRLVM can't catch all reference fields
updates, and the problem is identified to be caused by new jit opts
that do not observe the write barrier invariant for fields updates.
For example, JIT may generate code to copy consecutive fields of an
object without invoking write barrier. In order to revive the write
barrier functionality while not sacrificing the opt performance, I'd
suggest to introduce an object remember write barrier which will be
invoked after the object is copied. So the JIT doesn't need to insert
barrier for each field store. GC has an interface
gc_heap_wrote_object(p_obj) for this case.  I think it's ok to insert
only the runtime native call at first. Then later we can consider to
inline the object remembering barrier as well as the slot remembering


View raw message