--- /dev/null	2020-01-17 11:46:19.065201212 +0100
+++ new/src/hotspot/share/gc/shenandoah/heuristics/shenandoahAggressiveHeuristics.cpp	2020-01-17 17:09:40.155132130 +0100
@@ -0,0 +1,96 @@
+/*
+ * 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/heuristics/shenandoahAggressiveHeuristics.hpp"
+#include "gc/shenandoah/shenandoahCollectionSet.hpp"
+#include "gc/shenandoah/shenandoahHeapRegion.hpp"
+#include "logging/log.hpp"
+#include "logging/logTag.hpp"
+#include "runtime/os.hpp"
+
+ShenandoahAggressiveHeuristics::ShenandoahAggressiveHeuristics() : ShenandoahHeuristics() {
+  // Do not shortcut evacuation
+  SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahImmediateThreshold, 100);
+
+  // Aggressive runs with max speed for allocation, to capture races against mutator
+  SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahPacing);
+
+  // Aggressive evacuates everything, so it needs as much evac space as it can get
+  SHENANDOAH_ERGO_ENABLE_FLAG(ShenandoahEvacReserveOverflow);
+
+  // If class unloading is globally enabled, aggressive does unloading even with
+  // concurrent cycles.
+  if (ClassUnloading) {
+    SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahUnloadClassesFrequency, 1);
+  }
+
+  // Final configuration checks
+  SHENANDOAH_CHECK_FLAG_SET(ShenandoahLoadRefBarrier);
+  SHENANDOAH_CHECK_FLAG_SET(ShenandoahSATBBarrier);
+  SHENANDOAH_CHECK_FLAG_SET(ShenandoahKeepAliveBarrier);
+  SHENANDOAH_CHECK_FLAG_SET(ShenandoahCASBarrier);
+  SHENANDOAH_CHECK_FLAG_SET(ShenandoahCloneBarrier);
+}
+
+void ShenandoahAggressiveHeuristics::choose_collection_set_from_regiondata(ShenandoahCollectionSet* cset,
+                                                                           RegionData* data, size_t size,
+                                                                           size_t free) {
+  for (size_t idx = 0; idx < size; idx++) {
+    ShenandoahHeapRegion* r = data[idx]._region;
+    if (r->garbage() > 0) {
+      cset->add_region(r);
+    }
+  }
+}
+
+bool ShenandoahAggressiveHeuristics::should_start_gc() const {
+  log_info(gc)("Trigger: Start next cycle immediately");
+  return true;
+}
+
+bool ShenandoahAggressiveHeuristics::should_process_references() {
+  if (!can_process_references()) return false;
+  // Randomly process refs with 50% chance.
+  return (os::random() & 1) == 1;
+}
+
+bool ShenandoahAggressiveHeuristics::should_unload_classes() {
+  if (!can_unload_classes_normal()) return false;
+  if (has_metaspace_oom()) return true;
+  // Randomly unload classes with 50% chance.
+  return (os::random() & 1) == 1;
+}
+
+const char* ShenandoahAggressiveHeuristics::name() {
+  return "aggressive";
+}
+
+bool ShenandoahAggressiveHeuristics::is_diagnostic() {
+  return true;
+}
+
+bool ShenandoahAggressiveHeuristics::is_experimental() {
+  return false;
+}