decoder.hpp revision 8550:b8a3be10a4ed 
1/*
2 * Copyright (c) 1997, 2015, 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#include "runtime/mutexLocker.hpp"
32
33class AbstractDecoder : public CHeapObj<mtInternal> {
34public:
35  // status code for decoding native C frame
36  enum decoder_status {
37         not_available = -10,  // real decoder is not available
38         no_error = 0,         // successfully decoded frames
39         out_of_memory,        // out of memory
40         file_invalid,         // invalid elf file
41         file_not_found,       // could not found symbol file (on windows), such as jvm.pdb or jvm.map
42         helper_not_found,     // could not load dbghelp.dll (Windows only)
43         helper_func_error,    // decoding functions not found (Windows only)
44         helper_init_error     // SymInitialize failed (Windows only)
45  };
46
47  // decode an pc address to corresponding function name and an offset from the beginning of
48  // the function
49  //
50  // Note: the 'base' variant does not demangle names. The
51  // demangling that was done systematically in the 'modulepath' variant
52  // is now optional.
53  virtual bool decode(address pc, char* buf, int buflen, int* offset,
54                      const char* modulepath = NULL, bool demangle = true) = 0;
55  virtual bool decode(address pc, char* buf, int buflen, int* offset, const void* base) = 0;
56
57  // demangle a C++ symbol
58  virtual bool demangle(const char* symbol, char* buf, int buflen) = 0;
59  // if the decoder can decode symbols in vm
60  virtual bool can_decode_C_frame_in_vm() const = 0;
61
62  virtual decoder_status status() const {
63    return _decoder_status;
64  }
65
66  virtual bool has_error() const {
67    return is_error(_decoder_status);
68  }
69
70  static bool is_error(decoder_status status) {
71    return (status > 0);
72  }
73
74protected:
75  decoder_status  _decoder_status;
76};
77
78// Do nothing decoder
79class NullDecoder : public AbstractDecoder {
80public:
81  NullDecoder() {
82    _decoder_status = not_available;
83  }
84
85  ~NullDecoder() {};
86
87  virtual bool decode(address pc, char* buf, int buflen, int* offset,
88                      const char* modulepath, bool demangle) {
89    return false;
90  }
91
92  virtual bool decode(address pc, char* buf, int buflen, int* offset, const void* base) {
93    return false;
94  }
95
96  virtual bool demangle(const char* symbol, char* buf, int buflen) {
97    return false;
98  }
99
100  virtual bool can_decode_C_frame_in_vm() const {
101    return false;
102  }
103};
104
105
106class Decoder : AllStatic {
107public:
108  static bool decode(address pc, char* buf, int buflen, int* offset, const char* modulepath = NULL, bool demangle = true);
109  static bool decode(address pc, char* buf, int buflen, int* offset, bool demangle) {
110    return decode(pc, buf, buflen, offset, (const char*) NULL, demangle);
111  }
112  static bool decode(address pc, char* buf, int buflen, int* offset, const void* base);
113  static bool demangle(const char* symbol, char* buf, int buflen);
114  static bool can_decode_C_frame_in_vm();
115
116  // shutdown shared instance
117  static void shutdown();
118protected:
119  // shared decoder instance, _shared_instance_lock is needed
120  static AbstractDecoder* get_shared_instance();
121  // a private instance for error handler. Error handler can be
122  // triggered almost everywhere, including signal handler, where
123  // no lock can be taken. So the shared decoder can not be used
124  // in this scenario.
125  static AbstractDecoder* get_error_handler_instance();
126
127  static AbstractDecoder* create_decoder();
128private:
129  static AbstractDecoder*     _shared_decoder;
130  static AbstractDecoder*     _error_handler_decoder;
131  static NullDecoder          _do_nothing_decoder;
132
133protected:
134  static Mutex*               _shared_decoder_lock;
135  static Mutex* shared_decoder_lock();
136
137  friend class DecoderLocker;
138};
139
140class DecoderLocker : public MutexLockerEx {
141  AbstractDecoder* _decoder;
142  inline bool is_first_error_thread();
143public:
144  DecoderLocker();
145  AbstractDecoder* decoder() {
146    return _decoder;
147  }
148};
149
150#endif // SHARE_VM_UTILITIES_DECODER_HPP
151