--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1RootProcessor.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2015, 2017, 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.
+ *
+ */
+
+#ifndef SHARE_VM_GC_G1_G1ROOTPROCESSOR_HPP
+#define SHARE_VM_GC_G1_G1ROOTPROCESSOR_HPP
+
+#include "gc/shared/strongRootsScope.hpp"
+#include "memory/allocation.hpp"
+#include "runtime/mutex.hpp"
+
+class CLDClosure;
+class CodeBlobClosure;
+class G1CollectedHeap;
+class G1EvacuationRootClosures;
+class G1GCPhaseTimes;
+class G1RootClosures;
+class Monitor;
+class OopClosure;
+class SubTasksDone;
+
+// Scoped object to assist in applying oop, CLD and code blob closures to
+// root locations. Handles claiming of different root scanning tasks
+// and takes care of global state for root scanning via a StrongRootsScope.
+// In the parallel case there is a shared G1RootProcessor object where all
+// worker thread call the process_roots methods.
+class G1RootProcessor : public StackObj {
+  G1CollectedHeap* _g1h;
+  SubTasksDone _process_strong_tasks;
+  StrongRootsScope _srs;
+
+  // Used to implement the Thread work barrier.
+  Monitor _lock;
+  volatile jint _n_workers_discovered_strong_classes;
+
+  enum G1H_process_roots_tasks {
+    G1RP_PS_Universe_oops_do,
+    G1RP_PS_JNIHandles_oops_do,
+    G1RP_PS_ObjectSynchronizer_oops_do,
+    G1RP_PS_Management_oops_do,
+    G1RP_PS_SystemDictionary_oops_do,
+    G1RP_PS_ClassLoaderDataGraph_oops_do,
+    G1RP_PS_jvmti_oops_do,
+    G1RP_PS_CodeCache_oops_do,
+    G1RP_PS_aot_oops_do,
+    G1RP_PS_filter_satb_buffers,
+    G1RP_PS_refProcessor_oops_do,
+    // Leave this one last.
+    G1RP_PS_NumElements
+  };
+
+  void worker_has_discovered_all_strong_classes();
+  void wait_until_all_strong_classes_discovered();
+
+  void process_all_roots(OopClosure* oops,
+                         CLDClosure* clds,
+                         CodeBlobClosure* blobs,
+                         bool process_string_table);
+
+  void process_java_roots(G1RootClosures* closures,
+                          G1GCPhaseTimes* phase_times,
+                          uint worker_i);
+
+  void process_vm_roots(G1RootClosures* closures,
+                        G1GCPhaseTimes* phase_times,
+                        uint worker_i);
+
+  void process_string_table_roots(G1RootClosures* closures,
+                                  G1GCPhaseTimes* phase_times,
+                                  uint worker_i);
+
+  void process_code_cache_roots(CodeBlobClosure* code_closure,
+                                G1GCPhaseTimes* phase_times,
+                                uint worker_i);
+
+public:
+  G1RootProcessor(G1CollectedHeap* g1h, uint n_workers);
+
+  // Apply closures to the strongly and weakly reachable roots in the system
+  // in a single pass.
+  // Record and report timing measurements for sub phases using the worker_i
+  void evacuate_roots(G1EvacuationRootClosures* closures, uint worker_i);
+
+  // Apply oops, clds and blobs to all strongly reachable roots in the system
+  void process_strong_roots(OopClosure* oops,
+                            CLDClosure* clds,
+                            CodeBlobClosure* blobs);
+
+  // Apply oops, clds and blobs to strongly and weakly reachable roots in the system
+  void process_all_roots(OopClosure* oops,
+                         CLDClosure* clds,
+                         CodeBlobClosure* blobs);
+
+  // Apply oops, clds and blobs to strongly and weakly reachable roots in the system,
+  // the only thing different from process_all_roots is that we skip the string table
+  // to avoid keeping every string live when doing class unloading.
+  void process_all_roots_no_string_table(OopClosure* oops,
+                                         CLDClosure* clds,
+                                         CodeBlobClosure* blobs);
+
+  // Number of worker threads used by the root processor.
+  uint n_workers() const;
+};
+
+#endif // SHARE_VM_GC_G1_G1ROOTPROCESSOR_HPP