6978187: G1: assert(ParallelGCThreads> 1 || n_yielded() == _hrrs->occupied()) strikes again Summary: An evacuation failure while copying the roots caused an object, A, to be forwarded to itself. During the subsequent RSet updating a reference to A was processed causing the reference to be added to the RSet of A's heap region. As a result of adding to the remembered set we ran into the issue described in 6930581 - the sparse table expanded and the RSet scanning code walked the cards in one instance of RHashTable (_cur) while the occupied() counts the cards in the expanded table (_next). Reviewed-by: tonyp, iveresov

--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Mon Nov 15 16:25:14 2010 -0800
+++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Tue Nov 16 14:07:33 2010 -0800
@@ -795,6 +795,7 @@
     _worker_i(worker_i),
     _g1h(g1)
   { }
+
   bool doHeapRegion(HeapRegion* r) {
     if (!r->continuesHumongous()) {
       _cl.set_from(r);