rev 3388 : imported patch dcmd-fixes

   1 /*
   2  * Copyright (c) 2012, 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     _delim = ' ';
 199   }
 200   void add_dcmd_option(GenDCmdArgument* arg);
 201   void add_dcmd_argument(GenDCmdArgument* arg);
 202   GenDCmdArgument* lookup_dcmd_option(const char* name, size_t len);
 203   GenDCmdArgument* arguments_list() { return _arguments_list; };
 204   void check(TRAPS);
 205   void parse(CmdLine* line, char delim, TRAPS);
 206   void print_help(outputStream* out, const char* cmd_name);
 207   void reset(TRAPS);
 208   void cleanup();
 209   int num_arguments();
 210   GrowableArray<const char*>* argument_name_array();
 211   GrowableArray<DCmdArgumentInfo*>* argument_info_array();
 212 };
 213 
 214 // The DCmd class is the parent class of all diagnostic commands
 215 // Diagnostic command instances should not be instantiated directly but
 216 // created using the associated factory. The factory can be retrieved with
 217 // the DCmdFactory::getFactory() method.
 218 // A diagnostic command instance can either be allocated in the resource Area
 219 // or in the C-heap. Allocation in the resource area is recommended when the
 220 // current thread is the only one which will access the diagnostic command
 221 // instance. Allocation in the C-heap is required when the diagnostic command
 222 // is accessed by several threads (for instance to perform asynchronous
 223 // execution).
 224 // To ensure a proper cleanup, it's highly recommended to use a DCmdMark for
 225 // each diagnostic command instance. In case of a C-heap allocated diagnostic
 226 // command instance, the DCmdMark must be created in the context of the last
 227 // thread that will access the instance.
 228 class DCmd : public ResourceObj {
 229 protected:
 230   outputStream* _output;
 231   bool          _is_heap_allocated;
 232 public:
 233   DCmd(outputStream* output, bool heap_allocated) {
 234     _output = output;
 235     _is_heap_allocated = heap_allocated;
 236   }
 237 
 238   static const char* name() { return "No Name";}
 239   static const char* description() { return "No Help";}
 240   static const char* disabled_message() { return "Diagnostic command currently disabled"; }










 241   static const char* impact() { return "Low: No impact"; }
 242   static int num_arguments() { return 0; }
 243   outputStream* output() { return _output; }
 244   bool is_heap_allocated()  { return _is_heap_allocated; }
 245   virtual void print_help(const char* name) {
 246     output()->print_cr("Syntax: %s", name);
 247   }
 248   virtual void parse(CmdLine* line, char delim, TRAPS) {
 249     DCmdArgIter iter(line->args_addr(), line->args_len(), delim);
 250     bool has_arg = iter.next(CHECK);
 251     if (has_arg) {
 252       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 253                 "Unknown argument in diagnostic command");
 254     }
 255   }
 256   virtual void execute(TRAPS) { }
 257   virtual void reset(TRAPS) { }
 258   virtual void cleanup() { }
 259 
 260   // support for the JMX interface
 261   virtual GrowableArray<const char*>* argument_name_array() {
 262     GrowableArray<const char*>* array = new GrowableArray<const char*>(0);
 263     return array;
 264   }
 265   virtual GrowableArray<DCmdArgumentInfo*>* argument_info_array() {
 266     GrowableArray<DCmdArgumentInfo*>* array = new GrowableArray<DCmdArgumentInfo*>(0);
 267     return array;
 268   }
 269 
 270   // main method to invoke the framework
 271   static void parse_and_execute(outputStream* out, const char* cmdline,
 272                                 char delim, TRAPS);
 273 };
 274 
 275 class DCmdWithParser : public DCmd {
 276 protected:
 277   DCmdParser _dcmdparser;
 278 public:
 279   DCmdWithParser (outputStream *output, bool heap=false) : DCmd(output, heap) { }
 280   static const char* name() { return "No Name";}
 281   static const char* description() { return "No Help";}
 282   static const char* disabled_message() { return "Diagnostic command currently disabled"; }
 283   static const char* impact() { return "Low: No impact"; }
 284   static int num_arguments() { return 0; }
 285   virtual void parse(CmdLine *line, char delim, TRAPS);
 286   virtual void execute(TRAPS) { }
 287   virtual void reset(TRAPS);
 288   virtual void cleanup();
 289   virtual void print_help(const char* name);
 290   virtual GrowableArray<const char*>* argument_name_array();
 291   virtual GrowableArray<DCmdArgumentInfo*>* argument_info_array();
 292 };
 293 
 294 class DCmdMark : public StackObj {
 295   DCmd* _ref;
 296 public:
 297   DCmdMark(DCmd* cmd) { _ref = cmd; }
 298   ~DCmdMark() {
 299     if (_ref != NULL) {
 300       _ref->cleanup();
 301       if (_ref->is_heap_allocated()) {
 302         delete _ref;
 303       }
 304     }
 305   }
 306 };
 307 
 308 // Diagnostic commands are not directly instantiated but created with a factory.
 309 // Each diagnostic command class has its own factory. The DCmdFactory class also
 310 // manages the status of the diagnostic command (hidden, enabled). A DCmdFactory
 311 // has to be registered to make the diagnostic command available (see
 312 // management.cpp)
 313 class DCmdFactory: public CHeapObj {
 314 private:
 315   static Mutex*       _dcmdFactory_lock;
 316   // Pointer to the next factory in the singly-linked list of registered
 317   // diagnostic commands
 318   DCmdFactory*        _next;
 319   // When disabled, a diagnostic command cannot be executed. Any attempt to
 320   // execute it will result in the printing of the disabled message without
 321   // instantiating the command.
 322   bool                _enabled;
 323   // When hidden, a diagnostic command doesn't appear in the list of commands
 324   // provided by the 'help' command.
 325   bool                _hidden;
 326   int                 _num_arguments;
 327   static DCmdFactory* _DCmdFactoryList;
 328 public:
 329   DCmdFactory(int num_arguments, bool enabled, bool hidden) {
 330     _next = NULL;
 331     _enabled = enabled;
 332     _hidden = hidden;
 333     _num_arguments = num_arguments;
 334   }
 335   bool is_enabled() const { return _enabled; }
 336   void set_enabled(bool b) { _enabled = b; }
 337   bool is_hidden() const { return _hidden; }
 338   void set_hidden(bool b) { _hidden = b; }
 339   int num_arguments() { return _num_arguments; }
 340   DCmdFactory* next() { return _next; }
 341   virtual DCmd* create_Cheap_instance(outputStream* output) = 0;
 342   virtual DCmd* create_resource_instance(outputStream* output) = 0;
 343   virtual const char* name() const = 0;
 344   virtual const char* description() const = 0;
 345   virtual const char* impact() const = 0;
 346   virtual const char* disabled_message() const = 0;
 347   // Register a DCmdFactory to make a diagnostic command available.
 348   // Once registered, a diagnostic command must not be unregistered.
 349   // To prevent a diagnostic command from being executed, just set the
 350   // enabled flag to false.
 351   static int register_DCmdFactory(DCmdFactory* factory);
 352   static DCmdFactory* factory(const char* cmd, size_t len);
 353   // Returns a C-heap allocated diagnostic command for the given command line
 354   static DCmd* create_global_DCmd(CmdLine &line, outputStream* out, TRAPS);
 355   // Returns a resourceArea allocated diagnostic command for the given command line
 356   static DCmd* create_local_DCmd(CmdLine &line, outputStream* out, TRAPS);
 357   static GrowableArray<const char*>* DCmd_list();
 358   static GrowableArray<DCmdInfo*>* DCmdInfo_list();
 359 
 360   friend class HelpDCmd;
 361 };
 362 
 363 // Template to easily create DCmdFactory instances. See management.cpp
 364 // where this template is used to create and register factories.
 365 template <class DCmdClass> class DCmdFactoryImpl : public DCmdFactory {
 366 public:
 367   DCmdFactoryImpl(bool enabled, bool hidden) :
 368     DCmdFactory(DCmdClass::num_arguments(), enabled, hidden) { }
 369   // Returns a C-heap allocated instance
 370   virtual DCmd* create_Cheap_instance(outputStream* output) {
 371     return new (ResourceObj::C_HEAP) DCmdClass(output, true);
 372   }
 373   // Returns a resourceArea allocated instance
 374   virtual DCmd* create_resource_instance(outputStream* output) {
 375     return new DCmdClass(output, false);
 376   }
 377   virtual const char* name() const {
 378     return DCmdClass::name();
 379   }
 380   virtual const char* description() const {
 381     return DCmdClass::description();
 382   }
 383   virtual const char* impact() const {
 384     return DCmdClass::impact();
 385   }
 386   virtual const char* disabled_message() const {
 387      return DCmdClass::disabled_message();
 388   }
 389 };
 390 
 391 // This class provides a convenient way to register Dcmds, without a need to change
 392 // management.cpp every time. Body of these two methods resides in
 393 // diagnosticCommand.cpp
 394 
 395 class DCmdRegistrant : public AllStatic {
 396 
 397 private:
 398     static void register_dcmds();
 399     static void register_dcmds_ext();
 400 
 401     friend class Management;
 402 };
 403 
 404 #endif // SHARE_VM_SERVICES_DIAGNOSTICFRAMEWORK_HPP
--- EOF ---