--- a/hotspot/src/share/vm/gc/g1/g1RootClosures.cpp	Wed Nov 25 17:32:44 2015 +0000
+++ b/hotspot/src/share/vm/gc/g1/g1RootClosures.cpp	Wed Nov 25 21:54:05 2015 +0100
@@ -23,62 +23,7 @@
  */
 
 #include "precompiled.hpp"
-
-#include "gc/g1/bufferingOopClosure.hpp"
-#include "gc/g1/g1CodeBlobClosure.hpp"
-#include "gc/g1/g1CollectedHeap.hpp"
-#include "gc/g1/g1OopClosures.inline.hpp"
-#include "gc/g1/g1RootClosures.hpp"
-
-class G1ParScanThreadState;
-
-// Simple holder object for a complete set of closures used by the G1 evacuation code.
-template <G1Mark Mark>
-class G1SharedClosures VALUE_OBJ_CLASS_SPEC {
-public:
-  G1ParCopyClosure<G1BarrierNone,  Mark> _oops;
-  G1ParCopyClosure<G1BarrierKlass, Mark> _oop_in_klass;
-  G1KlassScanClosure                     _klass_in_cld_closure;
-  CLDToKlassAndOopClosure                _clds;
-  G1CodeBlobClosure                      _codeblobs;
-  BufferingOopClosure                    _buffered_oops;
-
-  G1SharedClosures(G1CollectedHeap* g1h, G1ParScanThreadState* pss, bool process_only_dirty_klasses, bool must_claim_cld) :
-    _oops(g1h, pss),
-    _oop_in_klass(g1h, pss),
-    _klass_in_cld_closure(&_oop_in_klass, process_only_dirty_klasses),
-    _clds(&_klass_in_cld_closure, &_oops, must_claim_cld),
-    _codeblobs(&_oops),
-    _buffered_oops(&_oops) {}
-};
-
-class G1EvacuationClosures : public G1EvacuationRootClosures {
-  G1SharedClosures<G1MarkNone> _closures;
-
-public:
-  G1EvacuationClosures(G1CollectedHeap* g1h,
-                       G1ParScanThreadState* pss,
-                       bool gcs_are_young) :
-      _closures(g1h, pss, gcs_are_young, /* must_claim_cld */ false) {}
-
-  OopClosure* weak_oops()   { return &_closures._buffered_oops; }
-  OopClosure* strong_oops() { return &_closures._buffered_oops; }
-
-  CLDClosure* weak_clds()             { return &_closures._clds; }
-  CLDClosure* strong_clds()           { return &_closures._clds; }
-  CLDClosure* thread_root_clds()      { return NULL; }
-  CLDClosure* second_pass_weak_clds() { return NULL; }
-
-  CodeBlobClosure* strong_codeblobs()      { return &_closures._codeblobs; }
-  CodeBlobClosure* weak_codeblobs()        { return &_closures._codeblobs; }
-
-  void flush()                 { _closures._buffered_oops.done(); }
-  double closure_app_seconds() { return _closures._buffered_oops.closure_app_seconds(); }
-
-  OopClosure* raw_strong_oops() { return &_closures._oops; }
-
-  bool trace_metadata()         { return false; }
-};
+#include "gc/g1/g1RootClosures.inline.hpp"
 
 // Closures used during initial mark.
 // The treatment of "weak" roots is selectable through the template parameter,
@@ -137,13 +82,19 @@
 };
 
 G1EvacuationRootClosures* G1EvacuationRootClosures::create_root_closures(G1ParScanThreadState* pss, G1CollectedHeap* g1h) {
+  G1EvacuationRootClosures* res = create_root_closures_ext(pss, g1h);
+  if (res != NULL) {
+    return res;
+  }
+
   if (g1h->collector_state()->during_initial_mark_pause()) {
     if (ClassUnloadingWithConcurrentMark) {
-      return new G1InitalMarkClosures<G1MarkPromotedFromRoot>(g1h, pss);
+      res = new G1InitalMarkClosures<G1MarkPromotedFromRoot>(g1h, pss);
     } else {
-      return new G1InitalMarkClosures<G1MarkFromRoot>(g1h, pss);
+      res = new G1InitalMarkClosures<G1MarkFromRoot>(g1h, pss);
     }
   } else {
-    return new G1EvacuationClosures(g1h, pss, g1h->collector_state()->gcs_are_young());
+    res = new G1EvacuationClosures(g1h, pss, g1h->collector_state()->gcs_are_young());
   }
+  return res;
 }

--- a/hotspot/src/share/vm/gc/g1/g1RootClosures.hpp	Wed Nov 25 17:32:44 2015 +0000
+++ b/hotspot/src/share/vm/gc/g1/g1RootClosures.hpp	Wed Nov 25 21:54:05 2015 +0100
@@ -49,6 +49,7 @@
 };
 
 class G1EvacuationRootClosures : public G1RootClosures {
+  static G1EvacuationRootClosures* create_root_closures_ext(G1ParScanThreadState* pss, G1CollectedHeap* g1h);
 public:
   // Flush any buffered state and deferred processing
   virtual void flush() = 0;

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc/g1/g1RootClosures.inline.hpp	Wed Nov 25 21:54:05 2015 +0100
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * 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 "gc/g1/bufferingOopClosure.hpp"
+#include "gc/g1/g1CodeBlobClosure.hpp"
+#include "gc/g1/g1CollectedHeap.hpp"
+#include "gc/g1/g1OopClosures.inline.hpp"
+#include "gc/g1/g1RootClosures.hpp"
+
+// Simple holder object for a complete set of closures used by the G1 evacuation code.
+template <G1Mark Mark>
+class G1SharedClosures VALUE_OBJ_CLASS_SPEC {
+public:
+  G1ParCopyClosure<G1BarrierNone,  Mark> _oops;
+  G1ParCopyClosure<G1BarrierKlass, Mark> _oop_in_klass;
+  G1KlassScanClosure                     _klass_in_cld_closure;
+  CLDToKlassAndOopClosure                _clds;
+  G1CodeBlobClosure                      _codeblobs;
+  BufferingOopClosure                    _buffered_oops;
+
+  G1SharedClosures(G1CollectedHeap* g1h, G1ParScanThreadState* pss, bool process_only_dirty_klasses, bool must_claim_cld) :
+    _oops(g1h, pss),
+    _oop_in_klass(g1h, pss),
+    _klass_in_cld_closure(&_oop_in_klass, process_only_dirty_klasses),
+    _clds(&_klass_in_cld_closure, &_oops, must_claim_cld),
+    _codeblobs(&_oops),
+    _buffered_oops(&_oops) {}
+};
+
+class G1EvacuationClosures : public G1EvacuationRootClosures {
+  G1SharedClosures<G1MarkNone> _closures;
+
+public:
+  G1EvacuationClosures(G1CollectedHeap* g1h,
+                       G1ParScanThreadState* pss,
+                       bool gcs_are_young) :
+      _closures(g1h, pss, gcs_are_young, /* must_claim_cld */ false) {}
+
+  OopClosure* weak_oops()   { return &_closures._buffered_oops; }
+  OopClosure* strong_oops() { return &_closures._buffered_oops; }
+
+  CLDClosure* weak_clds()             { return &_closures._clds; }
+  CLDClosure* strong_clds()           { return &_closures._clds; }
+  CLDClosure* thread_root_clds()      { return NULL; }
+  CLDClosure* second_pass_weak_clds() { return NULL; }
+
+  CodeBlobClosure* strong_codeblobs()      { return &_closures._codeblobs; }
+  CodeBlobClosure* weak_codeblobs()        { return &_closures._codeblobs; }
+
+  void flush()                 { _closures._buffered_oops.done(); }
+  double closure_app_seconds() { return _closures._buffered_oops.closure_app_seconds(); }
+
+  OopClosure* raw_strong_oops() { return &_closures._oops; }
+
+  bool trace_metadata()         { return false; }
+};

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc/g1/g1RootClosures_ext.cpp	Wed Nov 25 21:54:05 2015 +0100
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * 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/g1/g1RootClosures.hpp"
+
+G1EvacuationRootClosures* G1EvacuationRootClosures::create_root_closures_ext(G1ParScanThreadState* pss, G1CollectedHeap* g1h) {
+  return NULL;
+}