src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp

@@ -4918,14 +4918,19 @@
       CodeBlobClosure* strong_code_cl;
 
       if (_g1h->g1_policy()->during_initial_mark_pause()) {
         // We also need to mark copied objects.
         strong_root_cl = &scan_mark_root_cl;
-        weak_root_cl   = &scan_mark_weak_root_cl;
         strong_cld_cl  = &scan_mark_cld_cl;
-        weak_cld_cl    = &scan_mark_weak_cld_cl;
         strong_code_cl = &scan_mark_code_cl;
+        if (ClassUnloadingWithConcurrentMark) {
+          weak_root_cl = &scan_mark_weak_root_cl;
+          weak_cld_cl  = &scan_mark_weak_cld_cl;
+        } else {
+          weak_root_cl = &scan_mark_root_cl;
+          weak_cld_cl  = &scan_mark_cld_cl;
+        }
       } else {
         strong_root_cl = &scan_only_root_cl;
         weak_root_cl   = &scan_only_root_cl;
         strong_cld_cl  = &scan_only_cld_cl;
         weak_cld_cl    = &scan_only_cld_cl;

@@ -4992,21 +4997,22 @@
   // First scan the shared roots.
   double ext_roots_start = os::elapsedTime();
   double closure_app_time_sec = 0.0;
 
   bool during_im = _g1h->g1_policy()->during_initial_mark_pause();
+  bool trace_metadata = during_im && ClassUnloadingWithConcurrentMark;
 
   BufferingOopClosure buf_scan_non_heap_roots(scan_non_heap_roots);
   BufferingOopClosure buf_scan_non_heap_weak_roots(scan_non_heap_weak_roots);
 
   process_roots(false, // no scoping; this is parallel code
                 SharedHeap::SO_None,
                 &buf_scan_non_heap_roots,
                 &buf_scan_non_heap_weak_roots,
                 scan_strong_clds,
-                // Initial Mark handles the weak CLDs separately.
-                (during_im ? NULL : scan_weak_clds),
+                // Unloading Initial Marks handle the weak CLDs separately.
+                (trace_metadata ? NULL : scan_weak_clds),
                 scan_strong_code);
 
   // Now the CM ref_processor roots.
   if (!_process_strong_tasks->is_task_claimed(G1H_PS_refProcessor_oops_do)) {
     // We need to treat the discovered reference lists of the

@@ -5014,11 +5020,11 @@
     // (which are added by the marking threads) on them live
     // until they can be processed at the end of marking.
     ref_processor_cm()->weak_oops_do(&buf_scan_non_heap_roots);
   }
 
-  if (during_im) {
+  if (trace_metadata) {
     // Barrier to make sure all workers passed
     // the strong CLD and strong nmethods phases.
     active_strong_roots_scope()->wait_until_all_workers_done_with_threads(n_par_threads());
 
     // Now take the complement of the strong CLDs.

@@ -6040,10 +6046,11 @@
   double end_par_time_sec;
 
   {
     StrongRootsScope srs(this);
     // InitialMark needs claim bits to keep track of the marked-through CLDs.
+    // FIXME: Needed?
     if (g1_policy()->during_initial_mark_pause()) {
       ClassLoaderDataGraph::clear_claimed_marks();
     }
 
     if (G1CollectedHeap::use_parallel_gc_threads()) {