1 /* 2 * Copyright (c) 1997, 2015, 2017, 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 virtual ~AbstractDecoder() {} 36 37 // status code for decoding native C frame 38 enum decoder_status { 39 not_available = -10, // real decoder is not available 40 no_error = 0, // successfully decoded frames 41 out_of_memory, // out of memory 42 file_invalid, // invalid elf file 43 file_not_found, // could not found symbol file (on windows), such as jvm.pdb or jvm.map 44 helper_not_found, // could not load dbghelp.dll (Windows only) 45 helper_func_error, // decoding functions not found (Windows only) 46 helper_init_error // SymInitialize failed (Windows only) 47 }; 48 49 // decode an pc address to corresponding function name and an offset from the beginning of 50 // the function 51 // 52 // Note: the 'base' variant does not demangle names. The 53 // demangling that was done systematically in the 'modulepath' variant 54 // is now optional. 55 virtual bool decode(address pc, char* buf, int buflen, int* offset, 56 const char* modulepath = NULL, bool demangle = true) = 0; 57 virtual bool decode(address pc, char* buf, int buflen, int* offset, const void* base) = 0; 58 59 // demangle a C++ symbol 60 virtual bool demangle(const char* symbol, char* buf, int buflen) = 0; 61 // if the decoder can decode symbols in vm 62 virtual bool can_decode_C_frame_in_vm() const = 0; 63 64 virtual decoder_status status() const { 65 return _decoder_status; 66 } 67 68 virtual bool has_error() const { 69 return is_error(_decoder_status); 70 } 71 72 static bool is_error(decoder_status status) { 73 return (status > 0); 74 } 75 76 protected: 77 decoder_status _decoder_status; 78 }; 79 80 // Do nothing decoder 81 class NullDecoder : public AbstractDecoder { 82 public: 83 NullDecoder() { 84 _decoder_status = not_available; 85 } 86 87 virtual ~NullDecoder() {}; 88 89 virtual bool decode(address pc, char* buf, int buflen, int* offset, 90 const char* modulepath, bool demangle) { 91 return false; 92 } 93 94 virtual bool decode(address pc, char* buf, int buflen, int* offset, const void* base) { 95 return false; 96 } 97 98 virtual bool demangle(const char* symbol, char* buf, int buflen) { 99 return false; 100 } 101 102 virtual bool can_decode_C_frame_in_vm() const { 103 return false; 104 } 105 }; 106 107 108 class Decoder : AllStatic { 109 public: 110 static bool decode(address pc, char* buf, int buflen, int* offset, const char* modulepath = NULL, bool demangle = true); 111 static bool decode(address pc, char* buf, int buflen, int* offset, bool demangle) { 112 return decode(pc, buf, buflen, offset, (const char*) NULL, demangle); 113 } 114 static bool decode(address pc, char* buf, int buflen, int* offset, const void* base); 115 static bool demangle(const char* symbol, char* buf, int buflen); 116 static bool can_decode_C_frame_in_vm(); 117 118 // shutdown shared instance 119 static void shutdown(); 120 protected: 121 // shared decoder instance, _shared_instance_lock is needed 122 static AbstractDecoder* get_shared_instance(); 123 // a private instance for error handler. Error handler can be 124 // triggered almost everywhere, including signal handler, where 125 // no lock can be taken. So the shared decoder can not be used 126 // in this scenario. 127 static AbstractDecoder* get_error_handler_instance(); 128 129 static AbstractDecoder* create_decoder(); 130 private: 131 static AbstractDecoder* _shared_decoder; 132 static AbstractDecoder* _error_handler_decoder; 133 static NullDecoder _do_nothing_decoder; 134 135 protected: 136 static Mutex* _shared_decoder_lock; 137 static Mutex* shared_decoder_lock(); 138 139 friend class DecoderLocker; 140 }; 141 142 class DecoderLocker : public MutexLockerEx { 143 AbstractDecoder* _decoder; 144 inline bool is_first_error_thread(); 145 public: 146 DecoderLocker(); 147 AbstractDecoder* decoder() { 148 return _decoder; 149 } 150 }; 151 152 #endif // SHARE_VM_UTILITIES_DECODER_HPP