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

rev 10535 : [backport] SATB buffer filtering/compaction hides unmarked objects until final-mark
rev 10548 : [backport] Forceful SATB buffer flushes should be time-periodic, not traffic-dependent

*** 175,184 ****
--- 175,200 ----
    size_t sz = _sz;
    size_t all_entries = sz / oopSize;
    size_t retained_entries = (sz - _index) / oopSize;
    size_t perc = retained_entries * 100 / all_entries;
    bool should_enqueue = perc > (size_t) G1SATBBufferEnqueueingThresholdPercent;
+ 
+   if (UseShenandoahGC) {
+     Thread* t = Thread::current();
+     if (t->is_force_satb_flush()) {
+       if (!should_enqueue && sz != _index) {
+         // Non-empty buffer is compacted, and we decided not to enqueue it.
+         // Shenandoah still wants to know about leftover work in that buffer eventually.
+         // This avoid dealing with these leftovers during the final-mark, after the buffers
+         // are drained completely.
+         // TODO: This can be extended to handle G1 too
+         should_enqueue = true;
+       }
+       t->set_force_satb_flush(false);
+     }
+   }
+ 
    return should_enqueue;
  }
  
  void ObjPtrQueue::apply_closure_and_empty(SATBBufferClosure* cl) {
    assert(SafepointSynchronize::is_at_safepoint(),