--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/recorder/stringpool/jfrStringPool.hpp	Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2016, 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_JFR_RECORDER_STRINGPOOL_JFRSTRINGPOOL_HPP
+#define SHARE_VM_JFR_RECORDER_STRINGPOOL_JFRSTRINGPOOL_HPP
+
+#include "jni.h"
+#include "jfr/recorder/storage/jfrMemorySpace.hpp"
+#include "jfr/recorder/storage/jfrMemorySpaceRetrieval.hpp"
+#include "jfr/recorder/stringpool/jfrStringPoolBuffer.hpp"
+
+class JfrChunkWriter;
+class JfrStringPool;
+class Mutex;
+
+typedef JfrMemorySpace<JfrStringPoolBuffer, JfrMspaceSequentialRetrieval, JfrStringPool> JfrStringPoolMspace;
+
+//
+// Although called JfrStringPool, a more succinct description would be
+// "backing storage for the string pool located in Java"
+//
+// There are no lookups in native, only the encoding of string constants to the stream.
+//
+class JfrStringPool : public JfrCHeapObj {
+ public:
+  static bool add(bool epoch, jlong id, jstring string, JavaThread* jt);
+  size_t write();
+  size_t write_at_safepoint();
+  size_t clear();
+
+  typedef JfrStringPoolMspace::Type Buffer;
+ private:
+  JfrStringPoolMspace* _free_list_mspace;
+  Mutex* _lock;
+  JfrChunkWriter& _chunkwriter;
+
+  // mspace callback
+  void register_full(Buffer* t, Thread* thread);
+  void lock();
+  void unlock();
+  DEBUG_ONLY(bool is_locked() const;)
+
+  static Buffer* lease_buffer(Thread* thread, size_t size = 0);
+  static Buffer* flush(Buffer* old, size_t used, size_t requested, Thread* t);
+
+  JfrStringPool(JfrChunkWriter& cw);
+  ~JfrStringPool();
+
+  static JfrStringPool& instance();
+  static JfrStringPool* create(JfrChunkWriter& cw);
+  bool initialize();
+  static void destroy();
+
+  friend class JfrRecorder;
+  friend class JfrRecorderService;
+  friend class JfrStringPoolFlush;
+  friend class JfrStringPoolWriter;
+  template <typename, template <typename> class, typename>
+  friend class JfrMemorySpace;
+};
+
+#endif // SHARE_VM_JFR_RECORDER_STRINGPOOL_JFRSTRINGPOOL_HPP