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 // The impact() method returns a description of the intrusiveness of the diagnostic
242 // command on the Java Virtual Machine behavior. The rational for this method is that some
243 // diagnostic commands can seriously disrupt the behavior of the Java Virtual Machine
244 // (for instance a Thread Dump for an application with several tens of thousands of threads,
245 // or a Head Dump with a 40GB+ heap size) and other diagnostic commands have no serious
246 // impact on the JVM (for instance, getting the command line arguments or the JVM version).
247 // The recommended format for the description is <impact level>: [longer description],
248 // where the impact level is selected among this list: {Low, Medium, High}. The optional
249 // longer description can provide more specific details like the fact that Thread Dump
250 // impact depends on the heap size.
251 static const char* impact() { return "Low: No impact"; }
252 static int num_arguments() { return 0; }
253 outputStream* output() { return _output; }
254 bool is_heap_allocated() { return _is_heap_allocated; }
255 virtual void print_help(const char* name) {
256 output()->print_cr("Syntax: %s", name);
257 }
258 virtual void parse(CmdLine* line, char delim, TRAPS) {
259 DCmdArgIter iter(line->args_addr(), line->args_len(), delim);
260 bool has_arg = iter.next(CHECK);
261 if (has_arg) {
262 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
263 "Argument list of diagnostic command should be empty.");
264 }
265 }
266 virtual void execute(TRAPS) { }
267 virtual void reset(TRAPS) { }
268 virtual void cleanup() { }
269
270 // support for the JMX interface
271 virtual GrowableArray<const char*>* argument_name_array() {
272 GrowableArray<const char*>* array = new GrowableArray<const char*>(0);
273 return array;
274 }
275 virtual GrowableArray<DCmdArgumentInfo*>* argument_info_array() {
276 GrowableArray<DCmdArgumentInfo*>* array = new GrowableArray<DCmdArgumentInfo*>(0);
277 return array;
278 }
279
280 // main method to invoke the framework
281 static void parse_and_execute(outputStream* out, const char* cmdline,
282 char delim, TRAPS);
283 };
284
285 class DCmdWithParser : public DCmd {
286 protected:
287 DCmdParser _dcmdparser;
288 public:
289 DCmdWithParser (outputStream *output, bool heap=false) : DCmd(output, heap) { }
290 static const char* name() { return "No Name";}
291 static const char* description() { return "No Help";}
292 static const char* disabled_message() { return "Diagnostic command currently disabled"; }
293 static const char* impact() { return "Low: No impact"; }
294 static int num_arguments() { return 0; }
295 virtual void parse(CmdLine *line, char delim, TRAPS);
296 virtual void execute(TRAPS) { }
297 virtual void reset(TRAPS);
298 virtual void cleanup();
299 virtual void print_help(const char* name);
300 virtual GrowableArray<const char*>* argument_name_array();
301 virtual GrowableArray<DCmdArgumentInfo*>* argument_info_array();
302 };
303
304 class DCmdMark : public StackObj {
305 DCmd* _ref;
306 public:
307 DCmdMark(DCmd* cmd) { _ref = cmd; }
308 ~DCmdMark() {
309 if (_ref != NULL) {
310 _ref->cleanup();
311 if (_ref->is_heap_allocated()) {
312 delete _ref;
313 }
314 }
315 }
316 };
317
318 // Diagnostic commands are not directly instantiated but created with a factory.
319 // Each diagnostic command class has its own factory. The DCmdFactory class also
320 // manages the status of the diagnostic command (hidden, enabled). A DCmdFactory
321 // has to be registered to make the diagnostic command available (see
322 // management.cpp)
323 class DCmdFactory: public CHeapObj {
324 private:
325 static Mutex* _dcmdFactory_lock;
326 // Pointer to the next factory in the singly-linked list of registered
327 // diagnostic commands
328 DCmdFactory* _next;
329 // When disabled, a diagnostic command cannot be executed. Any attempt to
330 // execute it will result in the printing of the disabled message without
331 // instantiating the command.
332 bool _enabled;
333 // When hidden, a diagnostic command doesn't appear in the list of commands
334 // provided by the 'help' command.
335 bool _hidden;
336 int _num_arguments;
337 static DCmdFactory* _DCmdFactoryList;
338 public:
339 DCmdFactory(int num_arguments, bool enabled, bool hidden) {
340 _next = NULL;
341 _enabled = enabled;
342 _hidden = hidden;
343 _num_arguments = num_arguments;
344 }
345 bool is_enabled() const { return _enabled; }
346 void set_enabled(bool b) { _enabled = b; }
347 bool is_hidden() const { return _hidden; }
348 void set_hidden(bool b) { _hidden = b; }
349 int num_arguments() { return _num_arguments; }
350 DCmdFactory* next() { return _next; }
351 virtual DCmd* create_Cheap_instance(outputStream* output) = 0;
352 virtual DCmd* create_resource_instance(outputStream* output) = 0;
353 virtual const char* name() const = 0;
354 virtual const char* description() const = 0;
355 virtual const char* impact() const = 0;
356 virtual const char* disabled_message() const = 0;
357 // Register a DCmdFactory to make a diagnostic command available.
358 // Once registered, a diagnostic command must not be unregistered.
359 // To prevent a diagnostic command from being executed, just set the
360 // enabled flag to false.
361 static int register_DCmdFactory(DCmdFactory* factory);
362 static DCmdFactory* factory(const char* cmd, size_t len);
363 // Returns a C-heap allocated diagnostic command for the given command line
364 static DCmd* create_global_DCmd(CmdLine &line, outputStream* out, TRAPS);
365 // Returns a resourceArea allocated diagnostic command for the given command line
366 static DCmd* create_local_DCmd(CmdLine &line, outputStream* out, TRAPS);
367 static GrowableArray<const char*>* DCmd_list();
368 static GrowableArray<DCmdInfo*>* DCmdInfo_list();
369
370 friend class HelpDCmd;
371 };
372
373 // Template to easily create DCmdFactory instances. See management.cpp
374 // where this template is used to create and register factories.
375 template <class DCmdClass> class DCmdFactoryImpl : public DCmdFactory {
376 public:
377 DCmdFactoryImpl(bool enabled, bool hidden) :
378 DCmdFactory(DCmdClass::num_arguments(), enabled, hidden) { }
379 // Returns a C-heap allocated instance
380 virtual DCmd* create_Cheap_instance(outputStream* output) {
381 return new (ResourceObj::C_HEAP) DCmdClass(output, true);
382 }
383 // Returns a resourceArea allocated instance
384 virtual DCmd* create_resource_instance(outputStream* output) {
385 return new DCmdClass(output, false);
386 }
387 virtual const char* name() const {
388 return DCmdClass::name();
389 }
390 virtual const char* description() const {
391 return DCmdClass::description();
392 }
393 virtual const char* impact() const {
394 return DCmdClass::impact();
395 }
396 virtual const char* disabled_message() const {
397 return DCmdClass::disabled_message();
398 }
399 };
400
401 // This class provides a convenient way to register Dcmds, without a need to change
402 // management.cpp every time. Body of these two methods resides in
403 // diagnosticCommand.cpp
404
405 class DCmdRegistrant : public AllStatic {
406
407 private:
408 static void register_dcmds();
409 static void register_dcmds_ext();
410
411 friend class Management;
412 };
413
414 #endif // SHARE_VM_SERVICES_DIAGNOSTICFRAMEWORK_HPP
--- EOF ---