1 /* 2 * Copyright (c) 2011, 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 #ifndef SHARE_VM_SERVICES_DIAGNOSTICFRAMEWORK_HPP 26 #define SHARE_VM_SERVICES_DIAGNOSTICFRAMEWORK_HPP 27 28 #include "classfile/vmSymbols.hpp" 29 #include "memory/allocation.hpp" 30 #include "runtime/arguments.hpp" 31 #include "runtime/os.hpp" 32 #include "runtime/vm_version.hpp" 33 #include "runtime/vmThread.hpp" 34 #include "utilities/ostream.hpp" 35 36 37 // CmdLine is the class used to handle a command line containing a single 38 // diagnostic command and its arguments. It provides methods to access the 39 // command name and the beginning of the arguments. The class is also 40 // able to identify commented command lines and the "stop" keyword 41 class CmdLine : public StackObj { 42 private: 43 const char* _cmd; 44 size_t _cmd_len; 45 const char* _args; 46 size_t _args_len; 47 public: 48 CmdLine(const char* line, size_t len, bool no_command_name); 49 const char* args_addr() const { return _args; } 50 size_t args_len() const { return _args_len; } 51 const char* cmd_addr() const { return _cmd; } 52 size_t cmd_len() const { return _cmd_len; } 53 bool is_empty() { return _cmd_len == 0; } 54 bool is_executable() { return is_empty() || _cmd[0] != '#'; } 55 bool is_stop() { return !is_empty() && strncmp("stop", _cmd, _cmd_len) == 0; } 56 }; 57 58 // Iterator class taking a character string in input and returning a CmdLine 59 // instance for each command line. The argument delimiter has to be specified. 60 class DCmdIter : public StackObj { 61 friend class DCmd; 62 private: 63 const char* _str; 64 char _delim; 65 size_t _len; 66 size_t _cursor; 67 public: 68 69 DCmdIter(const char* str, char delim) { 70 _str = str; 71 _delim = delim; 72 _len = strlen(str); 73 _cursor = 0; 74 } 75 bool has_next() { return _cursor < _len; } 76 CmdLine next() { 77 assert(_cursor <= _len, "Cannot iterate more"); 78 size_t n = _cursor; 79 while (n < _len && _str[n] != _delim) n++; 80 CmdLine line(&(_str[_cursor]), n - _cursor, false); 81 _cursor = n + 1; 82 // The default copy constructor of CmdLine is used to return a CmdLine 83 // instance to the caller. 84 return line; 85 } 86 }; 87 88 // Iterator class to iterate over diagnostic command arguments 89 class DCmdArgIter : public ResourceObj { 90 const char* _buffer; 91 size_t _len; 92 size_t _cursor; 93 const char* _key_addr; 94 size_t _key_len; 95 const char* _value_addr; 96 size_t _value_len; 97 char _delim; 98 public: 99 DCmdArgIter(const char* buf, size_t len, char delim) { 100 _buffer = buf; 101 _len = len; 102 _delim = delim; 103 _cursor = 0; 104 } 105 bool next(TRAPS); 106 const char* key_addr() { return _key_addr; } 107 size_t key_length() { return _key_len; } 108 const char* value_addr() { return _value_addr; } 109 size_t value_length() { return _value_len; } 110 }; 111 112 // A DCmdInfo instance provides a description of a diagnostic command. It is 113 // used to export the description to the JMX interface of the framework. 114 class DCmdInfo : public ResourceObj { 115 protected: 116 const char* _name; 117 const char* _description; 118 const char* _impact; 119 int _num_arguments; 120 bool _is_enabled; 121 public: 122 DCmdInfo(const char* name, 123 const char* description, 124 const char* impact, 125 int num_arguments, 126 bool enabled) { 127 this->_name = name; 128 this->_description = description; 129 this->_impact = impact; 130 this->_num_arguments = num_arguments; 131 this->_is_enabled = enabled; 132 } 133 const char* name() const { return _name; } 134 const char* description() const { return _description; } 135 const char* impact() const { return _impact; } 136 int num_arguments() const { return _num_arguments; } 137 bool is_enabled() const { return _is_enabled; } 138 139 static bool by_name(void* name, DCmdInfo* info); 140 }; 141 142 // A DCmdArgumentInfo instance provides a description of a diagnostic command 143 // argument. It is used to export the description to the JMX interface of the 144 // framework. 145 class DCmdArgumentInfo : public ResourceObj { 146 protected: 147 const char* _name; 148 const char* _description; 149 const char* _type; 150 const char* _default_string; 151 bool _mandatory; 152 bool _option; 153 int _position; 154 public: 155 DCmdArgumentInfo(const char* name, const char* description, const char* type, 156 const char* default_string, bool mandatory, bool option) { 157 this->_name = name; 158 this->_description = description; 159 this->_type = type; 160 this->_default_string = default_string; 161 this->_option = option; 162 this->_mandatory = mandatory; 163 this->_option = option; 164 this->_position = -1; 165 } 166 DCmdArgumentInfo(const char* name, const char* description, const char* type, 167 const char* default_string, bool mandatory, bool option, 168 int position) { 169 this->_name = name; 170 this->_description = description; 171 this->_type = type; 172 this->_default_string = default_string; 173 this->_option = option; 174 this->_mandatory = mandatory; 175 this->_option = option; 176 this->_position = position; 177 } 178 const char* name() const { return _name; } 179 const char* description() const { return _description; } 180 const char* type() const { return _type; } 181 const char* default_string() const { return _default_string; } 182 bool is_mandatory() const { return _mandatory; } 183 bool is_option() const { return _option; } 184 int position() const { return _position; } 185 }; 186 187 // The DCmdParser class can be used to create an argument parser for a 188 // diagnostic command. It is not mandatory to use it to parse arguments. 189 class DCmdParser { 190 private: 191 GenDCmdArgument* _options; 192 GenDCmdArgument* _arguments_list; 193 char _delim; 194 public: 195 DCmdParser() { 196 _options = NULL; 197 _arguments_list = NULL; 198 } 199 void add_dcmd_option(GenDCmdArgument* arg); 200 void add_dcmd_argument(GenDCmdArgument* arg); 201 GenDCmdArgument* lookup_dcmd_option(const char* name, size_t len); 202 GenDCmdArgument* arguments_list() { return _arguments_list; }; 203 void check(TRAPS); 204 void parse(CmdLine* line, char delim, TRAPS); 205 void print_help(outputStream* out, const char* cmd_name); 206 void reset(TRAPS); 207 void cleanup(); 208 int num_arguments(); 209 GrowableArray<const char*>* argument_name_array(); 210 GrowableArray<DCmdArgumentInfo*>* argument_info_array(); 211 }; 212 213 // The DCmd class is the parent class of all diagnostic commands 214 // Diagnostic command instances should not be instantiated directly but 215 // created using the associated factory. The factory can be retrieved with 216 // the DCmdFactory::getFactory() method. 217 // A diagnostic command instance can either be allocated in the resource Area 218 // or in the C-heap. Allocation in the resource area is recommended when the 219 // current thread is the only one which will access the diagnostic command 220 // instance. Allocation in the C-heap is required when the diagnostic command 221 // is accessed by several threads (for instance to perform asynchronous 222 // execution). 223 // To ensure a proper cleanup, it's highly recommended to use a DCmdMark for 224 // each diagnostic command instance. In case of a C-heap allocated diagnostic 225 // command instance, the DCmdMark must be created in the context of the last 226 // thread that will access the instance. 227 class DCmd : public ResourceObj { 228 protected: 229 outputStream* _output; 230 bool _is_heap_allocated; 231 public: 232 DCmd(outputStream* output, bool heap_allocated) { 233 _output = output; 234 _is_heap_allocated = heap_allocated; 235 } 236 237 static const char* name() { return "No Name";} 238 static const char* description() { return "No Help";} 239 static const char* disabled_message() { return "Diagnostic command currently disabled"; } 240 static const char* impact() { return "Low: No impact"; } 241 static int num_arguments() { return 0; } 242 outputStream* output() { return _output; } 243 bool is_heap_allocated() { return _is_heap_allocated; } 244 virtual void print_help(const char* name) { 245 output()->print_cr("Syntax: %s", name); 246 } 247 virtual void parse(CmdLine* line, char delim, TRAPS) { 248 DCmdArgIter iter(line->args_addr(), line->args_len(), delim); 249 bool has_arg = iter.next(CHECK); 250 if (has_arg) { 251 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), 252 "Unknown argument in diagnostic command"); 253 } 254 } 255 virtual void execute(TRAPS) { } 256 virtual void reset(TRAPS) { } 257 virtual void cleanup() { } 258 259 // support for the JMX interface 260 virtual GrowableArray<const char*>* argument_name_array() { 261 GrowableArray<const char*>* array = new GrowableArray<const char*>(0); 262 return array; 263 } 264 virtual GrowableArray<DCmdArgumentInfo*>* argument_info_array() { 265 GrowableArray<DCmdArgumentInfo*>* array = new GrowableArray<DCmdArgumentInfo*>(0); 266 return array; 267 } 268 269 // main method to invoke the framework 270 static void parse_and_execute(outputStream* out, const char* cmdline, 271 char delim, TRAPS); 272 }; 273 274 class DCmdWithParser : public DCmd { 275 protected: 276 DCmdParser _dcmdparser; 277 public: 278 DCmdWithParser (outputStream *output, bool heap=false) : DCmd(output, heap) { } 279 static const char* name() { return "No Name";} 280 static const char* description() { return "No Help";} 281 static const char* disabled_message() { return "Diagnostic command currently disabled"; } 282 static const char* impact() { return "Low: No impact"; } 283 static int num_arguments() { return 0; } 284 virtual void parse(CmdLine *line, char delim, TRAPS); 285 virtual void execute(TRAPS) { } 286 virtual void reset(TRAPS); 287 virtual void cleanup(); 288 virtual void print_help(const char* name); 289 virtual GrowableArray<const char*>* argument_name_array(); 290 virtual GrowableArray<DCmdArgumentInfo*>* argument_info_array(); 291 }; 292 293 class DCmdMark : public StackObj { 294 DCmd* _ref; 295 public: 296 DCmdMark(DCmd* cmd) { _ref = cmd; } 297 ~DCmdMark() { 298 if (_ref != NULL) { 299 _ref->cleanup(); 300 if (_ref->is_heap_allocated()) { 301 delete _ref; 302 } 303 } 304 } 305 }; 306 307 // Diagnostic commands are not directly instantiated but created with a factory. 308 // Each diagnostic command class has its own factory. The DCmdFactory class also 309 // manages the status of the diagnostic command (hidden, enabled). A DCmdFactory 310 // has to be registered to make the diagnostic command available (see 311 // management.cpp) 312 class DCmdFactory: public CHeapObj { 313 private: 314 static Mutex* _dcmdFactory_lock; 315 // Pointer to the next factory in the singly-linked list of registered 316 // diagnostic commands 317 DCmdFactory* _next; 318 // When disabled, a diagnostic command cannot be executed. Any attempt to 319 // execute it will result in the printing of the disabled message without 320 // instantiating the command. 321 bool _enabled; 322 // When hidden, a diagnostic command doesn't appear in the list of commands 323 // provided by the 'help' command. 324 bool _hidden; 325 int _num_arguments; 326 static DCmdFactory* _DCmdFactoryList; 327 public: 328 DCmdFactory(int num_arguments, bool enabled, bool hidden) { 329 _next = NULL; 330 _enabled = enabled; 331 _hidden = hidden; 332 _num_arguments = num_arguments; 333 } 334 bool is_enabled() const { return _enabled; } 335 void set_enabled(bool b) { _enabled = b; } 336 bool is_hidden() const { return _hidden; } 337 void set_hidden(bool b) { _hidden = b; } 338 int num_arguments() { return _num_arguments; } 339 DCmdFactory* next() { return _next; } 340 virtual DCmd* create_Cheap_instance(outputStream* output) = 0; 341 virtual DCmd* create_resource_instance(outputStream* output) = 0; 342 virtual const char* name() const = 0; 343 virtual const char* description() const = 0; 344 virtual const char* impact() const = 0; 345 virtual const char* disabled_message() const = 0; 346 // Register a DCmdFactory to make a diagnostic command available. 347 // Once registered, a diagnostic command must not be unregistered. 348 // To prevent a diagnostic command from being executed, just set the 349 // enabled flag to false. 350 static int register_DCmdFactory(DCmdFactory* factory); 351 static DCmdFactory* factory(const char* cmd, size_t len); 352 // Returns a C-heap allocated diagnostic command for the given command line 353 static DCmd* create_global_DCmd(CmdLine &line, outputStream* out, TRAPS); 354 // Returns a resourceArea allocated diagnostic command for the given command line 355 static DCmd* create_local_DCmd(CmdLine &line, outputStream* out, TRAPS); 356 static GrowableArray<const char*>* DCmd_list(); 357 static GrowableArray<DCmdInfo*>* DCmdInfo_list(); 358 359 friend class HelpDCmd; 360 }; 361 362 // Template to easily create DCmdFactory instances. See management.cpp 363 // where this template is used to create and register factories. 364 template <class DCmdClass> class DCmdFactoryImpl : public DCmdFactory { 365 public: 366 DCmdFactoryImpl(bool enabled, bool hidden) : 367 DCmdFactory(DCmdClass::num_arguments(), enabled, hidden) { } 368 // Returns a C-heap allocated instance 369 virtual DCmd* create_Cheap_instance(outputStream* output) { 370 return new (ResourceObj::C_HEAP) DCmdClass(output, true); 371 } 372 // Returns a resourceArea allocated instance 373 virtual DCmd* create_resource_instance(outputStream* output) { 374 return new DCmdClass(output, false); 375 } 376 virtual const char* name() const { 377 return DCmdClass::name(); 378 } 379 virtual const char* description() const { 380 return DCmdClass::description(); 381 } 382 virtual const char* impact() const { 383 return DCmdClass::impact(); 384 } 385 virtual const char* disabled_message() const { 386 return DCmdClass::disabled_message(); 387 } 388 }; 389 390 // This class provides a convenient way to register Dcmds, without a need to change 391 // management.cpp every time. Body of these two methods resides in 392 // diagnosticCommand.cpp 393 394 class DCmdRegistrant : public AllStatic { 395 396 private: 397 static void register_dcmds(); 398 static void register_dcmds_ext(); 399 400 friend class Management; 401 }; 402 403 #endif // SHARE_VM_SERVICES_DIAGNOSTICFRAMEWORK_HPP