decoder.hpp revision 3109:db006a85bf91 
1/*
2 * Copyright (c) 1997, 2012, 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.
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23 */
24
25
26#ifndef SHARE_VM_UTILITIES_DECODER_HPP
27#define SHARE_VM_UTILITIES_DECODER_HPP
28
29#include "memory/allocation.hpp"
30#include "runtime/mutex.hpp"
31
32class AbstractDecoder : public CHeapObj {
33public:
34  // status code for decoding native C frame
35  enum decoder_status {
36         not_available = -10,  // real decoder is not available
37         no_error = 0,         // successfully decoded frames
38         out_of_memory,        // out of memory
39         file_invalid,         // invalid elf file
40         file_not_found,       // could not found symbol file (on windows), such as jvm.pdb or jvm.map
41         helper_not_found,     // could not load dbghelp.dll (Windows only)
42         helper_func_error,    // decoding functions not found (Windows only)
43         helper_init_error     // SymInitialize failed (Windows only)
44  };
45
46  // decode an pc address to corresponding function name and an offset from the beginning of
47  // the function
48  virtual bool decode(address pc, char* buf, int buflen, int* offset,
49    const char* modulepath = NULL) = 0;
50  // demangle a C++ symbol
51  virtual bool demangle(const char* symbol, char* buf, int buflen) = 0;
52  // if the decoder can decode symbols in vm
53  virtual bool can_decode_C_frame_in_vm() const = 0;
54
55  virtual decoder_status status() const {
56    return _decoder_status;
57  }
58
59  virtual bool has_error() const {
60    return is_error(_decoder_status);
61  }
62
63  static bool is_error(decoder_status status) {
64    return (status > 0);
65  }
66
67protected:
68  decoder_status  _decoder_status;
69};
70
71// Do nothing decoder
72class NullDecoder : public AbstractDecoder {
73public:
74  NullDecoder() {
75    _decoder_status = not_available;
76  }
77
78  ~NullDecoder() {};
79
80  virtual bool decode(address pc, char* buf, int buflen, int* offset,
81    const char* modulepath = NULL) {
82    return false;
83  }
84
85  virtual bool demangle(const char* symbol, char* buf, int buflen) {
86    return false;
87  }
88
89  virtual bool can_decode_C_frame_in_vm() const {
90    return false;
91  }
92};
93
94
95class Decoder : AllStatic {
96public:
97  static bool decode(address pc, char* buf, int buflen, int* offset, const char* modulepath = NULL);
98  static bool demangle(const char* symbol, char* buf, int buflen);
99  static bool can_decode_C_frame_in_vm();
100
101  // shutdown shared instance
102  static void shutdown();
103protected:
104  // shared decoder instance, _shared_instance_lock is needed
105  static AbstractDecoder* get_shared_instance();
106  // a private instance for error handler. Error handler can be
107  // triggered almost everywhere, including signal handler, where
108  // no lock can be taken. So the shared decoder can not be used
109  // in this scenario.
110  static AbstractDecoder* get_error_handler_instance();
111
112  static AbstractDecoder* create_decoder();
113private:
114  static AbstractDecoder*     _shared_decoder;
115  static AbstractDecoder*     _error_handler_decoder;
116  static NullDecoder          _do_nothing_decoder;
117
118protected:
119  static Mutex*               _shared_decoder_lock;
120};
121
122#endif // SHARE_VM_UTILITIES_DECODER_HPP
123