1 /*
   2  * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_JFR_RECORDER_STRINGPOOL_JFRSTRINGPOOL_HPP
  26 #define SHARE_VM_JFR_RECORDER_STRINGPOOL_JFRSTRINGPOOL_HPP
  27 
  28 #include "jni.h"
  29 #include "jfr/recorder/storage/jfrMemorySpace.hpp"
  30 #include "jfr/recorder/storage/jfrMemorySpaceRetrieval.hpp"
  31 #include "jfr/recorder/stringpool/jfrStringPoolBuffer.hpp"
  32 
  33 class JfrChunkWriter;
  34 class JfrStringPool;
  35 class Mutex;
  36 
  37 typedef JfrMemorySpace<JfrStringPoolBuffer, JfrMspaceSequentialRetrieval, JfrStringPool> JfrStringPoolMspace;
  38 
  39 //
  40 // Although called JfrStringPool, a more succinct description would be
  41 // "backing storage for the string pool located in Java"
  42 //
  43 // There are no lookups in native, only the encoding of string constants to the stream.
  44 //
  45 class JfrStringPool : public JfrCHeapObj {
  46  public:
  47   static bool add(bool epoch, jlong id, jstring string, JavaThread* jt);
  48   size_t write();
  49   size_t clear();
  50 
  51   typedef JfrStringPoolMspace::Type Buffer;
  52  private:
  53   JfrStringPoolMspace* _free_list_mspace;
  54   JfrStringPoolMspace* _transient_mspace;
  55   Mutex* _lock;
  56   JfrChunkWriter& _chunkwriter;
  57 
  58   // mspace callback
  59   void register_full(Buffer* t, Thread* thread);
  60   void lock();
  61   void unlock();
  62 
  63   static Buffer* lease_buffer(Thread* thread, size_t size = 0);
  64   static Buffer* flush(Buffer* old, size_t used, size_t requested, Thread* t);
  65 
  66   JfrStringPool(JfrChunkWriter& cw);
  67   ~JfrStringPool();
  68 
  69   static JfrStringPool& instance();
  70   static JfrStringPool* create(JfrChunkWriter& cw);
  71   bool initialize();
  72   static void destroy();
  73 
  74   friend class JfrRecorder;
  75   friend class JfrRecorderService;
  76   friend class JfrStringPoolFlush;
  77   friend class JfrStringPoolWriter;
  78   template <typename, template <typename> class, typename>
  79   friend class JfrMemorySpace;
  80 };
  81 
  82 #endif // SHARE_VM_JFR_RECORDER_STRINGPOOL_JFRSTRINGPOOL_HPP