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 write_at_safepoint();

    50   size_t clear();

    51 

    52   typedef JfrStringPoolMspace::Type Buffer;

    53  private:

    54   JfrStringPoolMspace* _free_list_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   DEBUG_ONLY(bool is_locked() const;)

    63 

    64   static Buffer* lease_buffer(Thread* thread, size_t size = 0);

    65   static Buffer* flush(Buffer* old, size_t used, size_t requested, Thread* t);

    66 

    67   JfrStringPool(JfrChunkWriter& cw);

    68   ~JfrStringPool();

    69 

    70   static JfrStringPool& instance();

    71   static JfrStringPool* create(JfrChunkWriter& cw);

    72   bool initialize();

    73   static void destroy();

    74 

    75   friend class JfrRecorder;

    76   friend class JfrRecorderService;

    77   friend class JfrStringPoolFlush;

    78   friend class JfrStringPoolWriter;

    79   template <typename, template <typename> class, typename>

    80   friend class JfrMemorySpace;

    81 };

    82 

    83 #endif // SHARE_VM_JFR_RECORDER_STRINGPOOL_JFRSTRINGPOOL_HPP