--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1ConcurrentMarkThread.hpp	Tue Apr 03 12:05:49 2018 +0200
@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2001, 2018, 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_G1CONCURRENTMARKTHREAD_HPP
+#define SHARE_VM_GC_G1_G1CONCURRENTMARKTHREAD_HPP
+
+#include "gc/shared/concurrentGCPhaseManager.hpp"
+#include "gc/shared/concurrentGCThread.hpp"
+
+class G1ConcurrentMark;
+class G1Policy;
+
+// The concurrent mark thread triggers the various steps of the concurrent marking
+// cycle, including various marking cleanup.
+class G1ConcurrentMarkThread: public ConcurrentGCThread {
+  friend class VMStructs;
+
+  double _vtime_start;  // Initial virtual time.
+  double _vtime_accum;  // Accumulated virtual time.
+  double _vtime_mark_accum;
+
+  G1ConcurrentMark* _cm;
+
+  enum State {
+    Idle,
+    Started,
+    InProgress
+  };
+
+  volatile State _state;
+
+  // WhiteBox testing support.
+  ConcurrentGCPhaseManager::Stack _phase_manager_stack;
+
+  void sleep_before_next_cycle();
+  // Delay marking to meet MMU.
+  void delay_to_keep_mmu(G1Policy* g1_policy, bool remark);
+  double mmu_sleep_time(G1Policy* g1_policy, bool remark);
+
+  void run_service();
+  void stop_service();
+
+ public:
+  // Constructor
+  G1ConcurrentMarkThread(G1ConcurrentMark* cm);
+
+  // Total virtual time so far for this thread and concurrent marking tasks.
+  double vtime_accum();
+  // Marking virtual time so far this thread and concurrent marking tasks.
+  double vtime_mark_accum();
+
+  G1ConcurrentMark* cm()   { return _cm; }
+
+  void set_idle()          { assert(_state != Started, "must not be starting a new cycle"); _state = Idle; }
+  bool idle()              { return _state == Idle; }
+  void set_started()       { assert(_state == Idle, "cycle in progress"); _state = Started; }
+  bool started()           { return _state == Started; }
+  void set_in_progress()   { assert(_state == Started, "must be starting a cycle"); _state = InProgress; }
+  bool in_progress()       { return _state == InProgress; }
+
+  // Returns true from the moment a marking cycle is
+  // initiated (during the initial-mark pause when started() is set)
+  // to the moment when the cycle completes (just after the next
+  // marking bitmap has been cleared and in_progress() is
+  // cleared). While during_cycle() is true we will not start another cycle
+  // so that cycles do not overlap. We cannot use just in_progress()
+  // as the CM thread might take some time to wake up before noticing
+  // that started() is set and set in_progress().
+  bool during_cycle()      { return !idle(); }
+
+  // WhiteBox testing support.
+  const char* const* concurrent_phases() const;
+  bool request_concurrent_phase(const char* phase);
+
+  ConcurrentGCPhaseManager::Stack* phase_manager_stack() {
+    return &_phase_manager_stack;
+  }
+};
+
+#endif // SHARE_VM_GC_G1_G1CONCURRENTMARKTHREAD_HPP