--- a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp	Thu Sep 04 18:40:43 2008 -0700
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp	Wed Sep 17 16:49:18 2008 +0400
@@ -790,7 +790,7 @@
 }
 
 
-HeapWord* CompactibleFreeListSpace::block_start(const void* p) const {
+HeapWord* CompactibleFreeListSpace::block_start_const(const void* p) const {
   NOT_PRODUCT(verify_objects_initialized());
   return _bt.block_start(p);
 }
@@ -2286,9 +2286,9 @@
 }
 
 void CompactibleFreeListSpace::verifyIndexedFreeList(size_t size) const {
-  guarantee(size % 2 == 0, "Odd slots should be empty");
-  for (FreeChunk* fc = _indexedFreeList[size].head(); fc != NULL;
-    fc = fc->next()) {
+  FreeChunk* fc =  _indexedFreeList[size].head();
+  guarantee((size % 2 == 0) || fc == NULL, "Odd slots should be empty");
+  for (; fc != NULL; fc = fc->next()) {
     guarantee(fc->size() == size, "Size inconsistency");
     guarantee(fc->isFree(), "!free?");
     guarantee(fc->next() == NULL || fc->next()->prev() == fc, "Broken list");
@@ -2790,10 +2790,11 @@
   assert(n_threads > 0, "Unexpected n_threads argument");
   const size_t task_size = rescan_task_size();
   size_t n_tasks = (used_region().word_size() + task_size - 1)/task_size;
-  assert((used_region().start() + (n_tasks - 1)*task_size <
-          used_region().end()) &&
-         (used_region().start() + n_tasks*task_size >=
-          used_region().end()), "n_task calculation incorrect");
+  assert((n_tasks == 0) == used_region().is_empty(), "n_tasks incorrect");
+  assert(n_tasks == 0 ||
+         ((used_region().start() + (n_tasks - 1)*task_size < used_region().end()) &&
+          (used_region().start() + n_tasks*task_size >= used_region().end())),
+         "n_tasks calculation incorrect");
   SequentialSubTasksDone* pst = conc_par_seq_tasks();
   assert(!pst->valid(), "Clobbering existing data?");
   pst->set_par_threads(n_threads);
@@ -2833,7 +2834,7 @@
   assert(n_tasks == 0 ||
          ((span.start() + (n_tasks - 1)*task_size < span.end()) &&
           (span.start() + n_tasks*task_size >= span.end())),
-         "n_task calculation incorrect");
+         "n_tasks calculation incorrect");
   SequentialSubTasksDone* pst = conc_par_seq_tasks();
   assert(!pst->valid(), "Clobbering existing data?");
   pst->set_par_threads(n_threads);