--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/runtime/safepointMechanism.hpp	Thu Aug 31 10:00:28 2017 +0200
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 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_RUNTIME_SAFEPOINTMECHANISM_HPP
+#define SHARE_VM_RUNTIME_SAFEPOINTMECHANISM_HPP
+
+#include "runtime/globals.hpp"
+#include "utilities/globalDefinitions.hpp"
+#include "utilities/macros.hpp"
+#include "utilities/sizes.hpp"
+
+// This is the abstracted interface for the safepoint implementation
+class SafepointMechanism : public AllStatic {
+  enum PollingType {
+    _global_page_poll,
+    _thread_local_poll
+  };
+  static PollingType _polling_type;
+  static void* _poll_armed_value;
+  static void* _poll_disarmed_value;
+  static void set_uses_thread_local_poll()            { _polling_type     = _thread_local_poll; }
+
+  static void* poll_armed_value()                     { return _poll_armed_value; }
+  static void* poll_disarmed_value()                  { return _poll_disarmed_value; }
+
+  static inline bool local_poll_armed(JavaThread* thread);
+
+  static inline bool local_poll(Thread* thread);
+  static inline bool global_poll();
+
+  static inline void block_if_requested_local_poll(JavaThread *thread);
+
+  static void default_initialize();
+  static void initialize_serialize_page();
+
+  static void pd_initialize() NOT_AIX({ default_initialize(); });
+
+  // By adding 8 to the base address of the protected polling page we can differentiate
+  // between the armed and disarmed value by masking out this bit.
+  const static intptr_t _poll_bit = 8;
+public:
+  static intptr_t poll_bit() { return _poll_bit; }
+
+  static bool uses_global_page_poll() { return _polling_type == _global_page_poll; }
+  static bool uses_thread_local_poll() { return _polling_type == _thread_local_poll; }
+
+  static bool supports_thread_local_poll() {
+#ifdef THREAD_LOCAL_POLL
+    return true;
+#else
+    return false;
+#endif
+  }
+
+  // Call this method to see if this thread has depending poll and appropriate action should be taken
+  static inline bool poll(Thread* thread);
+
+  // Blocks a thread until safepoint is completed
+  static inline void block_if_requested(JavaThread* thread);
+
+  static inline void arm_local_poll(JavaThread* thread);
+  static inline void disarm_local_poll(JavaThread* thread);
+
+  // Setup the selected safepoint mechanism
+  static void initialize();
+  static void initialize_header(JavaThread* thread);
+};
+
+#endif // SHARE_VM_RUNTIME_SAFEPOINTMECHANISM_HPP