1 /*

     2  * Copyright (c) 2017, 2019, 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_JFR_WRITERS_JFRTYPEWRITERHOST_HPP

    26 #define SHARE_JFR_WRITERS_JFRTYPEWRITERHOST_HPP

    27 

    28 #include "jfr/recorder/checkpoint/jfrCheckpointWriter.hpp"

    29 #include "jfr/utilities/jfrTypes.hpp"

    30 #include "memory/allocation.hpp"

    31 

    32 template <typename WriterImpl, u4 ID>

    33 class JfrTypeWriterHost : public StackObj {

    34  private:

    35   WriterImpl _impl;

    36   JfrCheckpointWriter* _writer;

    37   JfrCheckpointContext _ctx;

    38   int64_t _count_offset;

    39   int _count;

    40   bool _skip_header;

    41  public:

    42   JfrTypeWriterHost(JfrCheckpointWriter* writer,

    43                     bool class_unload = false,

    44                     bool skip_header = false) : _impl(writer, class_unload),

    45                                                 _writer(writer),

    46                                                 _ctx(writer->context()),

    47                                                 _count(0),

    48                                                 _skip_header(skip_header) {

    49     assert(_writer != NULL, "invariant");

    50     if (!_skip_header) {

    51       _writer->write_type((JfrTypeId)ID);

    52       _count_offset = _writer->reserve(sizeof(u4)); // Don't know how many yet

    53     }

    54   }

    55 

    56   ~JfrTypeWriterHost() {

    57     if (_count == 0) {

    58       // nothing written, restore context for rewind

    59       _writer->set_context(_ctx);

    60       return;

    61     }

    62     assert(_count > 0, "invariant");

    63     if (!_skip_header) {

    64       _writer->write_count(_count, _count_offset);

    65     }

    66   }

    67 

    68   bool operator()(typename WriterImpl::Type const & value) {

    69     this->_count += _impl(value);

    70     return true;

    71   }

    72 

    73   int count() const   { return _count; }

    74   void add(int count) { _count += count; }

    75 };

    76 

    77 typedef int(*type_write_operation)(JfrCheckpointWriter*, const void*);

    78 

    79 template <typename T, type_write_operation op>

    80 class JfrTypeWriterImplHost {

    81  private:

    82   JfrCheckpointWriter* _writer;

    83  public:

    84   typedef T Type;

    85   JfrTypeWriterImplHost(JfrCheckpointWriter* writer, bool class_unload = false) : _writer(writer) {}

    86   int operator()(T const& value) {

    87     return op(this->_writer, value);

    88   }

    89 };

    90 

    91 template <typename T, typename Predicate, type_write_operation op>

    92 class JfrPredicatedTypeWriterImplHost : public JfrTypeWriterImplHost<T, op> {

    93  private:

    94   Predicate _predicate;

    95   typedef JfrTypeWriterImplHost<T, op> Parent;

    96  public:

    97   JfrPredicatedTypeWriterImplHost(JfrCheckpointWriter* writer, bool class_unload = false) :

    98     Parent(writer), _predicate(class_unload) {}

    99   int operator()(T const& value) {

   100     return _predicate(value) ? Parent::operator()(value) : 0;

   101   }

   102 };

   103 

   104 #endif // SHARE_JFR_WRITERS_JFRTYPEWRITERHOST_HPP