1 /*
   2  * Copyright (c) 2017, 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_CHECKPOINT_CONSTANT_JFRTAGSETWRITER_HPP
  26 #define SHARE_VM_JFR_CHECKPOINT_CONSTANT_JFRTAGSETWRITER_HPP
  27 
  28 #include "jfr/recorder/checkpoint/jfrCheckpointWriter.hpp"
  29 #include "memory/allocation.hpp"
  30 // to get CONTENT_TYPE defines
  31 #include "tracefiles/traceTypes.hpp"
  32 
  33 template <typename WriterImpl, u4 CONSTANT_TYPE_ID>
  34 class JfrArtifactWriterHost : public StackObj {
  35  private:
  36   WriterImpl _impl;
  37   JfrCheckpointWriter* _writer;
  38   JfrCheckpointContext _ctx;
  39   jlong _count_offset;
  40   int _count;
  41   bool _skip_header;
  42  public:
  43   JfrArtifactWriterHost(JfrCheckpointWriter* writer,
  44                         JfrArtifactSet* artifacts,
  45                         bool class_unload,
  46                         bool skip_header = false) : _impl(writer, artifacts, class_unload),
  47                                                     _writer(writer),
  48                                                     _ctx(writer->context()),
  49                                                     _count(0),
  50                                                     _skip_header(skip_header) {
  51     assert(_writer != NULL, "invariant");
  52     if (!_skip_header) {
  53       _writer->write_constant_type((JfrConstantTypeId)CONSTANT_TYPE_ID);
  54       _count_offset = _writer->reserve(sizeof(u4)); // Don't know how many yet
  55     }
  56   }
  57 
  58   ~JfrArtifactWriterHost() {
  59     if (_count == 0) {
  60       // nothing written, restore context for rewind
  61       _writer->set_context(_ctx);
  62       return;
  63     }
  64     assert(_count > 0, "invariant");
  65     if (!_skip_header) {
  66       _writer->write_number_of_constants(_count, _count_offset);
  67     }
  68   }
  69 
  70   bool operator()(typename WriterImpl::Type const & value) {
  71     this->_count += _impl(value);
  72     return true;
  73   }
  74 
  75   int count() const   { return _count; }
  76   void add(int count) { _count += count; }
  77 };
  78 
  79 typedef int(*artifact_write_operation)(JfrCheckpointWriter*, JfrArtifactSet*, const void*);
  80 
  81 template <typename T, artifact_write_operation op>
  82 class JfrArtifactWriterImplHost {
  83  private:
  84   JfrCheckpointWriter* _writer;
  85   JfrArtifactSet* _artifacts;
  86   bool _class_unload;
  87  public:
  88   typedef T Type;
  89   JfrArtifactWriterImplHost(JfrCheckpointWriter* writer, JfrArtifactSet* artifacts, bool class_unload) :
  90     _writer(writer), _artifacts(artifacts), _class_unload(class_unload) {}
  91   int operator()(T const& value) {
  92     return op(this->_writer, this->_artifacts, value);
  93   }
  94 };
  95 
  96 template <typename T, typename Predicate, artifact_write_operation op>
  97 class JfrPredicatedArtifactWriterImplHost : public JfrArtifactWriterImplHost<T, op> {
  98  private:
  99   Predicate _predicate;
 100   typedef JfrArtifactWriterImplHost<T, op> Parent;
 101  public:
 102   JfrPredicatedArtifactWriterImplHost(JfrCheckpointWriter* writer, JfrArtifactSet* artifacts, bool class_unload) :
 103     Parent(writer, artifacts, class_unload), _predicate(class_unload) {}
 104   int operator()(T const& value) {
 105     return _predicate(value) ? Parent::operator()(value) : 0;
 106   }
 107 };
 108 
 109 #endif // SHARE_VM_JFR_CHECKPOINT_CONSTANT_JFRTAGSETWRITER_HPP