1 /*
   2  * Copyright (c) 1997, 2013, 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 #include "precompiled.hpp"
  26 #include "prims/jvm.h"
  27 #include "runtime/os.hpp"
  28 #include "utilities/decoder.hpp"
  29 #include "utilities/vmError.hpp"
  30 
  31 #if defined(_WINDOWS)
  32   #include "decoder_windows.hpp"
  33 #elif defined(__APPLE__)
  34   #include "decoder_machO.hpp"
  35 #elif defined(AIX)
  36   #include "decoder_aix.hpp"
  37 #else
  38   #include "decoder_elf.hpp"
  39 #endif
  40 
  41 AbstractDecoder*  Decoder::_shared_decoder = NULL;
  42 AbstractDecoder*  Decoder::_error_handler_decoder = NULL;
  43 NullDecoder       Decoder::_do_nothing_decoder;
  44 Mutex*            Decoder::_shared_decoder_lock = new Mutex(Mutex::native,
  45                                 "SharedDecoderLock");
  46 
  47 AbstractDecoder* Decoder::get_shared_instance() {
  48   assert(_shared_decoder_lock != NULL && _shared_decoder_lock->owned_by_self(),
  49     "Require DecoderLock to enter");
  50 
  51   if (_shared_decoder == NULL) {
  52     _shared_decoder = create_decoder();
  53   }
  54   return _shared_decoder;
  55 }
  56 
  57 AbstractDecoder* Decoder::get_error_handler_instance() {
  58   if (_error_handler_decoder == NULL) {
  59     _error_handler_decoder = create_decoder();
  60   }
  61   return _error_handler_decoder;
  62 }
  63 
  64 
  65 AbstractDecoder* Decoder::create_decoder() {
  66   AbstractDecoder* decoder;
  67 #if defined(_WINDOWS)
  68   decoder = new (std::nothrow) WindowsDecoder();
  69 #elif defined (__APPLE__)
  70   decoder = new (std::nothrow)MachODecoder();
  71 #elif defined(AIX)
  72   decoder = new (std::nothrow)AIXDecoder();
  73 #else
  74   decoder = new (std::nothrow)ElfDecoder();
  75 #endif
  76 
  77   if (decoder == NULL || decoder->has_error()) {
  78     if (decoder != NULL) {
  79       delete decoder;
  80     }
  81     decoder = &_do_nothing_decoder;
  82   }
  83   return decoder;
  84 }
  85 
  86 inline bool DecoderLocker::is_first_error_thread() {
  87   return (os::current_thread_id() == VMError::get_first_error_tid());
  88 }
  89 
  90 DecoderLocker::DecoderLocker() :
  91   MutexLockerEx(DecoderLocker::is_first_error_thread() ?
  92                 NULL : Decoder::shared_decoder_lock(), true) {
  93   _decoder = is_first_error_thread() ?
  94     Decoder::get_error_handler_instance() : Decoder::get_shared_instance();
  95   assert(_decoder != NULL, "null decoder");
  96 }
  97 
  98 Mutex* Decoder::shared_decoder_lock() {
  99   assert(_shared_decoder_lock != NULL, "Just check");
 100   return _shared_decoder_lock;
 101 }
 102 
 103 bool Decoder::decode(address addr, char* buf, int buflen, int* offset, const char* modulepath) {
 104   assert(_shared_decoder_lock != NULL, "Just check");
 105   bool error_handling_thread = os::current_thread_id() == VMError::first_error_tid;
 106   MutexLockerEx locker(error_handling_thread ? NULL : _shared_decoder_lock, true);
 107   AbstractDecoder* decoder = error_handling_thread ?
 108     get_error_handler_instance(): get_shared_instance();
 109   assert(decoder != NULL, "null decoder");
 110 
 111   return decoder->decode(addr, buf, buflen, offset, modulepath);
 112 }
 113 
 114 bool Decoder::decode(address addr, char* buf, int buflen, int* offset, const void* base) {
 115   assert(_shared_decoder_lock != NULL, "Just check");
 116   bool error_handling_thread = os::current_thread_id() == VMError::first_error_tid;
 117   MutexLockerEx locker(error_handling_thread ? NULL : _shared_decoder_lock, true);
 118   AbstractDecoder* decoder = error_handling_thread ?
 119     get_error_handler_instance(): get_shared_instance();
 120   assert(decoder != NULL, "null decoder");
 121 
 122   return decoder->decode(addr, buf, buflen, offset, base);
 123 }
 124 
 125 
 126 bool Decoder::demangle(const char* symbol, char* buf, int buflen) {
 127   assert(_shared_decoder_lock != NULL, "Just check");
 128   bool error_handling_thread = os::current_thread_id() == VMError::first_error_tid;
 129   MutexLockerEx locker(error_handling_thread ? NULL : _shared_decoder_lock, true);
 130   AbstractDecoder* decoder = error_handling_thread ?
 131     get_error_handler_instance(): get_shared_instance();
 132   assert(decoder != NULL, "null decoder");
 133   return decoder->demangle(symbol, buf, buflen);
 134 }
 135 
 136 bool Decoder::can_decode_C_frame_in_vm() {
 137   assert(_shared_decoder_lock != NULL, "Just check");
 138   bool error_handling_thread = os::current_thread_id() == VMError::first_error_tid;
 139   MutexLockerEx locker(error_handling_thread ? NULL : _shared_decoder_lock, true);
 140   AbstractDecoder* decoder = error_handling_thread ?
 141     get_error_handler_instance(): get_shared_instance();
 142   assert(decoder != NULL, "null decoder");
 143   return decoder->can_decode_C_frame_in_vm();
 144 }
 145 
 146 /*
 147  * Shutdown shared decoder and replace it with
 148  * _do_nothing_decoder. Do nothing with error handler
 149  * instance, since the JVM is going down.
 150  */
 151 void Decoder::shutdown() {
 152   assert(_shared_decoder_lock != NULL, "Just check");
 153   MutexLockerEx locker(_shared_decoder_lock, true);
 154 
 155   if (_shared_decoder != NULL &&
 156     _shared_decoder != &_do_nothing_decoder) {
 157     delete _shared_decoder;
 158   }
 159 
 160   _shared_decoder = &_do_nothing_decoder;
 161 }
 162