--- /dev/null	2018-11-30 10:10:44.238550338 +0100
+++ new/src/hotspot/share/gc/shenandoah/shenandoahSATBMarkQueueSet.cpp	2018-11-30 21:09:18.576726297 +0100
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2018, Red Hat, Inc. All rights reserved.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+
+#include "gc/shenandoah/shenandoahHeap.inline.hpp"
+#include "gc/shenandoah/shenandoahSATBMarkQueueSet.hpp"
+#include "gc/shenandoah/shenandoahThreadLocalData.hpp"
+
+ShenandoahSATBMarkQueueSet::ShenandoahSATBMarkQueueSet() :
+  _heap(NULL),
+  _satb_mark_queue_buffer_allocator(ShenandoahSATBBufferSize, SATB_Q_FL_lock)
+{}
+
+void ShenandoahSATBMarkQueueSet::initialize(ShenandoahHeap* const heap,
+                                            Monitor* cbl_mon,
+                                            int process_completed_threshold,
+                                            uint buffer_enqueue_threshold_percentage,
+                                            Mutex* lock) {
+  SATBMarkQueueSet::initialize(cbl_mon,
+                               &_satb_mark_queue_buffer_allocator,
+                               process_completed_threshold,
+                               buffer_enqueue_threshold_percentage,
+                               lock);
+  _heap = heap;
+}
+
+SATBMarkQueue& ShenandoahSATBMarkQueueSet::satb_queue_for_thread(JavaThread* const t) const {
+  return ShenandoahThreadLocalData::satb_mark_queue(t);
+}
+
+static inline bool discard_entry(const void* entry, ShenandoahHeap* heap) {
+  return !heap->requires_marking(entry);
+}
+
+class ShenandoahSATBMarkQueueFilterFn {
+  ShenandoahHeap* _heap;
+
+public:
+  ShenandoahSATBMarkQueueFilterFn(ShenandoahHeap* heap) : _heap(heap) {}
+
+  // Return true if entry should be filtered out (removed), false if
+  // it should be retained.
+  bool operator()(const void* entry) const {
+    return discard_entry(entry, _heap);
+  }
+};
+
+void ShenandoahSATBMarkQueueSet::filter(SATBMarkQueue* queue) {
+  assert(_heap != NULL, "SATB queue set not initialized");
+  apply_filter(ShenandoahSATBMarkQueueFilterFn(_heap), queue);
+}
+
+bool ShenandoahSATBMarkQueue::should_enqueue_buffer() {
+  bool should_enqueue = SATBMarkQueue::should_enqueue_buffer();
+  size_t cap = capacity();
+  Thread* t = Thread::current();
+  if (ShenandoahThreadLocalData::is_force_satb_flush(t)) {
+    if (!should_enqueue && cap != index()) {
+      // Non-empty buffer is compacted, and we decided not to enqueue it.
+      // We still want 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. See JDK-8205353 for more discussion.
+      should_enqueue = true;
+    }
+    ShenandoahThreadLocalData::set_force_satb_flush(t, false);
+  }
+  return should_enqueue;
+}