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.
22 *
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
33 class AbstractDecoder : public CHeapObj<mtInternal> {
34 public:
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
74 protected:
75 decoder_status _decoder_status;
76 };
77
78 // Do nothing decoder
79 class NullDecoder : public AbstractDecoder {
80 public:
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
106 class Decoder : AllStatic {
107 public:
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();
118 protected:
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();
128 private:
129 static AbstractDecoder* _shared_decoder;
130 static AbstractDecoder* _error_handler_decoder;
131 static NullDecoder _do_nothing_decoder;
132
133 protected:
134 static Mutex* _shared_decoder_lock;
135 static Mutex* shared_decoder_lock();
136
137 friend class DecoderLocker;
138 };
139
140 class DecoderLocker : public MutexLockerEx {
141 AbstractDecoder* _decoder;
142 inline bool is_first_error_thread();
143 public:
144 DecoderLocker();
145 AbstractDecoder* decoder() {
146 return _decoder;
147 }
148 };
149
150 #endif // SHARE_VM_UTILITIES_DECODER_HPP