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(outputStream* out) { };

   245   virtual void parse(CmdLine* line, char delim, TRAPS) { }

   246   virtual void execute(TRAPS) { }

   247   virtual void reset(TRAPS) { }

   248   virtual void cleanup() { }

   249 

   250   // support for the JMX interface

   251   virtual GrowableArray<const char*>* argument_name_array() {

   252     GrowableArray<const char*>* array = new GrowableArray<const char*>(0);

   253     return array;

   254   }

   255   virtual GrowableArray<DCmdArgumentInfo*>* argument_info_array() {

   256     GrowableArray<DCmdArgumentInfo*>* array = new GrowableArray<DCmdArgumentInfo*>(0);

   257     return array;

   258   }

   259 

   260   // main method to invoke the framework

   261   static void parse_and_execute(outputStream* out, const char* cmdline,

   262                                 char delim, TRAPS);

   263 };

   264 

   265 class DCmdMark : public StackObj {

   266   DCmd* _ref;

   267 public:

   268   DCmdMark(DCmd* cmd) { _ref = cmd; }

   269   ~DCmdMark() {

   270     if (_ref != NULL) {

   271       _ref->cleanup();

   272       if (_ref->is_heap_allocated()) {

   273         delete _ref;

   274       }

   275     }

   276   }

   277 };

   278 

   279 // Diagnostic commands are not directly instantiated but created with a factory.

   280 // Each diagnostic command class has its own factory. The DCmdFactory class also

   281 // manages the status of the diagnostic command (hidden, enabled). A DCmdFactory

   282 // has to be registered to make the diagnostic command available (see

   283 // management.cpp)

   284 class DCmdFactory: public CHeapObj {

   285 private:

   286   static Mutex*       _dcmdFactory_lock;

   287   // Pointer to the next factory in the singly-linked list of registered

   288   // diagnostic commands

   289   DCmdFactory*        _next;

   290   // When disabled, a diagnostic command cannot be executed. Any attempt to

   291   // execute it will result in the printing of the disabled message without

   292   // instantiating the command.

   293   bool                _enabled;

   294   // When hidden, a diagnostic command doesn't appear in the list of commands

   295   // provided by the 'help' command.

   296   bool                _hidden;

   297   int                 _num_arguments;

   298   static DCmdFactory* _DCmdFactoryList;

   299 public:

   300   DCmdFactory(int num_arguments, bool enabled, bool hidden) {

   301     _next = NULL;

   302     _enabled = enabled;

   303     _hidden = hidden;

   304     _num_arguments = num_arguments;

   305   }

   306   bool is_enabled() const { return _enabled; }

   307   void set_enabled(bool b) { _enabled = b; }

   308   bool is_hidden() const { return _hidden; }

   309   void set_hidden(bool b) { _hidden = b; }

   310   int num_arguments() { return _num_arguments; }

   311   DCmdFactory* next() { return _next; }

   312   virtual DCmd* create_Cheap_instance(outputStream* output) = 0;

   313   virtual DCmd* create_resource_instance(outputStream* output) = 0;

   314   virtual const char* name() const = 0;

   315   virtual const char* description() const = 0;

   316   virtual const char* impact() const = 0;

   317   virtual const char* disabled_message() const = 0;

   318   // Register a DCmdFactory to make a diagnostic command available.

   319   // Once registered, a diagnostic command must not be unregistered.

   320   // To prevent a diagnostic command from being executed, just set the

   321   // enabled flag to false.

   322   static int register_DCmdFactory(DCmdFactory* factory);

   323   static DCmdFactory* factory(const char* cmd, size_t len);

   324   // Returns a C-heap allocated diagnostic command for the given command line

   325   static DCmd* create_global_DCmd(CmdLine &line, outputStream* out, TRAPS);

   326   // Returns a resourceArea allocated diagnostic command for the given command line

   327   static DCmd* create_local_DCmd(CmdLine &line, outputStream* out, TRAPS);

   328   static GrowableArray<const char*>* DCmd_list();

   329   static GrowableArray<DCmdInfo*>* DCmdInfo_list();

   330 

   331   friend class HelpDCmd;

   332 };

   333 

   334 // Template to easily create DCmdFactory instances. See management.cpp

   335 // where this template is used to create and register factories.

   336 template <class DCmdClass> class DCmdFactoryImpl : public DCmdFactory {

   337 public:

   338   DCmdFactoryImpl(bool enabled, bool hidden) :

   339     DCmdFactory(DCmdClass::num_arguments(), enabled, hidden) { }

   340   // Returns a C-heap allocated instance

   341   virtual DCmd* create_Cheap_instance(outputStream* output) {

   342     return new (ResourceObj::C_HEAP) DCmdClass(output, true);

   343   }

   344   // Returns a resourceArea allocated instance

   345   virtual DCmd* create_resource_instance(outputStream* output) {

   346     return new DCmdClass(output, false);

   347   }

   348   virtual const char* name() const {

   349     return DCmdClass::name();

   350   }

   351   virtual const char* description() const {

   352     return DCmdClass::description();

   353   }

   354   virtual const char* impact() const {

   355     return DCmdClass::impact();

   356   }

   357   virtual const char* disabled_message() const {

   358      return DCmdClass::disabled_message();

   359   }

   360 };

   361 

   362 #endif // SHARE_VM_SERVICES_DIAGNOSTICFRAMEWORK_HPP