1 /*
2 * Copyright (c) 2001, 2008, 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 "incls/_precompiled.incl"
26 # include "incls/_statSampler.cpp.incl"
27
28 // --------------------------------------------------------
29 // StatSamplerTask
30
31 class StatSamplerTask : public PeriodicTask {
32 public:
33 StatSamplerTask(int interval_time) : PeriodicTask(interval_time) {}
34 void task() { StatSampler::collect_sample(); }
35 };
36
37
38 //----------------------------------------------------------
39 // Implementation of StatSampler
40
41 StatSamplerTask* StatSampler::_task = NULL;
42 PerfDataList* StatSampler::_sampled = NULL;
43
44 /*
45 * the initialize method is called from the engage() method
46 * and is responsible for initializing various global variables.
47 */
48 void StatSampler::initialize() {
49
50 if (!UsePerfData) return;
51
52 // create performance data that could not be created prior
53 // to vm_init_globals() or otherwise have no logical home.
54
55 create_misc_perfdata();
56
57 // get copy of the sampled list
58 _sampled = PerfDataManager::sampled();
59
60 }
61
62 /*
63 * The engage() method is called at initialization time via
64 * Thread::create_vm() to initialize the StatSampler and
65 * register it with the WatcherThread as a periodic task.
66 */
67 void StatSampler::engage() {
68
69 if (!UsePerfData) return;
70
71 if (!is_active()) {
72
73 initialize();
74
75 // start up the periodic task
76 _task = new StatSamplerTask(PerfDataSamplingInterval);
77 _task->enroll();
78 }
79 }
80
81
82 /*
83 * the disengage() method is responsible for deactivating the periodic
84 * task and, if logging was enabled, for logging the final sample. This
85 * method is called from before_exit() in java.cpp and is only called
86 * after the WatcherThread has been stopped.
87 */
88 void StatSampler::disengage() {
89
90 if (!UsePerfData) return;
91
92 if (!is_active())
93 return;
94
95 // remove StatSamplerTask
96 _task->disenroll();
97 delete _task;
98 _task = NULL;
99
100 // force a final sample
101 sample_data(_sampled);
102 }
103
104 /*
105 * the destroy method is responsible for releasing any resources used by
106 * the StatSampler prior to shutdown of the VM. this method is called from
107 * before_exit() in java.cpp and is only called after the WatcherThread
108 * has stopped.
109 */
110 void StatSampler::destroy() {
111
112 if (!UsePerfData) return;
113
114 if (_sampled != NULL) {
115 delete(_sampled);
116 _sampled = NULL;
117 }
118 }
119
120 /*
121 * The sample_data() method is responsible for sampling the
122 * the data value for each PerfData instance in the given list.
123 */
124 void StatSampler::sample_data(PerfDataList* list) {
125
126 assert(list != NULL, "null list unexpected");
127
128 for (int index = 0; index < list->length(); index++) {
129 PerfData* item = list->at(index);
130 item->sample();
131 }
132 }
133
134 /*
135 * the collect_sample() method is the method invoked by the
136 * WatcherThread via the PeriodicTask::task() method. This method
137 * is responsible for collecting data samples from sampled
138 * PerfData instances every PerfDataSamplingInterval milliseconds.
139 * It is also responsible for logging the requested set of
140 * PerfData instances every _sample_count milliseconds. While
141 * logging data, it will output a column header after every _print_header
142 * rows of data have been logged.
143 */
144 void StatSampler::collect_sample() {
145
146 // future - check for new PerfData objects. PerfData objects might
147 // get added to the PerfDataManager lists after we have already
148 // built our local copies.
149 //
150 // if (PerfDataManager::count() > previous) {
151 // // get a new copy of the sampled list
152 // if (_sampled != NULL) {
153 // delete(_sampled);
154 // _sampled = NULL;
155 // }
156 // _sampled = PerfDataManager::sampled();
157 // }
158
159 assert(_sampled != NULL, "list not initialized");
160
161 sample_data(_sampled);
162 }
163
164 /*
165 * method to upcall into Java to return the value of the specified
166 * property as a utf8 string, or NULL if does not exist. The caller
167 * is responsible for setting a ResourceMark for proper cleanup of
168 * the utf8 strings.
169 */
170 const char* StatSampler::get_system_property(const char* name, TRAPS) {
171
172 // setup the arguments to getProperty
173 Handle key_str = java_lang_String::create_from_str(name, CHECK_NULL);
174
175 // return value
176 JavaValue result(T_OBJECT);
177
178 // public static String getProperty(String key, String def);
179 JavaCalls::call_static(&result,
180 KlassHandle(THREAD, SystemDictionary::System_klass()),
181 vmSymbolHandles::getProperty_name(),
182 vmSymbolHandles::string_string_signature(),
183 key_str,
184 CHECK_NULL);
185
186 oop value_oop = (oop)result.get_jobject();
187 if (value_oop == NULL) {
188 return NULL;
189 }
190
191 // convert Java String to utf8 string
192 char* value = java_lang_String::as_utf8_string(value_oop);
193
194 return value;
195 }
196
197 /*
198 * The list of System Properties that have corresponding PerfData
199 * string instrumentation created by retrieving the named property's
200 * value from System.getProperty() and unconditionally creating a
201 * PerfStringConstant object initialized to the retreived value. This
202 * is not an exhustive list of Java properties with corresponding string
203 * instrumentation as the create_system_property_instrumentation() method
204 * creates other property based instrumentation conditionally.
205 */
206
207 // stable interface, supported counters
208 static const char* property_counters_ss[] = {
209 "java.vm.specification.version",
210 "java.vm.specification.name",
211 "java.vm.specification.vendor",
212 "java.vm.version",
213 "java.vm.name",
214 "java.vm.vendor",
215 "java.vm.info",
216 "java.library.path",
217 "java.class.path",
218 "java.endorsed.dirs",
219 "java.ext.dirs",
220 "java.version",
221 "java.home",
222 NULL
223 };
224
225 // unstable interface, supported counters
226 static const char* property_counters_us[] = {
227 NULL
228 };
229
230 // unstable interface, unsupported counters
231 static const char* property_counters_uu[] = {
232 "sun.boot.class.path",
233 "sun.boot.library.path",
234 NULL
235 };
236
237 typedef struct {
238 const char** property_list;
239 CounterNS name_space;
240 } PropertyCounters;
241
242 static PropertyCounters property_counters[] = {
243 { property_counters_ss, JAVA_PROPERTY },
244 { property_counters_us, COM_PROPERTY },
245 { property_counters_uu, SUN_PROPERTY },
246 { NULL, SUN_PROPERTY }
247 };
248
249
250 /*
251 * Method to create PerfData string instruments that contain the values
252 * of various system properties. String instruments are created for each
253 * property specified in the property lists provided in property_counters[].
254 * Property counters have a counter name space prefix prepended to the
255 * property name as indicated in property_counters[].
256 */
257 void StatSampler::create_system_property_instrumentation(TRAPS) {
258
259 ResourceMark rm;
260
261 for (int i = 0; property_counters[i].property_list != NULL; i++) {
262
263 for (int j = 0; property_counters[i].property_list[j] != NULL; j++) {
264
265 const char* property_name = property_counters[i].property_list[j];
266 assert(property_name != NULL, "property name should not be NULL");
267
268 const char* value = get_system_property(property_name, CHECK);
269
270 // the property must exist
271 assert(value != NULL, "property name should be valid");
272
273 if (value != NULL) {
274 // create the property counter
275 PerfDataManager::create_string_constant(property_counters[i].name_space,
276 property_name, value, CHECK);
277 }
278 }
279 }
280 }
281
282 /*
283 * The create_misc_perfdata() method provides a place to create
284 * PerfData instances that would otherwise have no better place
285 * to exist.
286 */
287 void StatSampler::create_misc_perfdata() {
288
289 ResourceMark rm;
290 EXCEPTION_MARK;
291
292 // numeric constants
293
294 // frequency of the native high resolution timer
295 PerfDataManager::create_constant(SUN_OS, "hrt.frequency",
296 PerfData::U_Hertz, os::elapsed_frequency(),
297 CHECK);
298
299 // string constants
300
301 // create string instrumentation for various Java properties.
302 create_system_property_instrumentation(CHECK);
303
304 // hotspot flags (from .hotspotrc) and args (from command line)
305 //
306 PerfDataManager::create_string_constant(JAVA_RT, "vmFlags",
307 Arguments::jvm_flags(), CHECK);
308 PerfDataManager::create_string_constant(JAVA_RT, "vmArgs",
309 Arguments::jvm_args(), CHECK);
310
311 // java class name/jar file and arguments to main class
312 // note: name is cooridnated with launcher and Arguments.cpp
313 PerfDataManager::create_string_constant(SUN_RT, "javaCommand",
314 Arguments::java_command(), CHECK);
315
316 // the Java VM Internal version string
317 PerfDataManager::create_string_constant(SUN_RT, "internalVersion",
318 VM_Version::internal_vm_info_string(),
319 CHECK);
320
321 // create sampled instrumentation objects
322 create_sampled_perfdata();
323 }
324
325 /*
326 * helper class to provide for sampling of the elapsed_counter value
327 * maintained in the OS class.
328 */
329 class HighResTimeSampler : public PerfSampleHelper {
330 public:
331 jlong take_sample() { return os::elapsed_counter(); }
332 };
333
334 /*
335 * the create_sampled_perdata() method provides a place to instantiate
336 * sampled PerfData instances that would otherwise have no better place
337 * to exist.
338 */
339 void StatSampler::create_sampled_perfdata() {
340
341 EXCEPTION_MARK;
342
343 // setup sampling of the elapsed time counter maintained in the
344 // the os class. This counter can be used as either a time stamp
345 // for each logged entry or as a liveness indicator for the VM.
346 PerfSampleHelper* psh = new HighResTimeSampler();
347 PerfDataManager::create_counter(SUN_OS, "hrt.ticks",
348 PerfData::U_Ticks, psh, CHECK);
349 }
350
351 /*
352 * the statSampler_exit() function is called from os_init.cpp on
353 * exit of the vm.
354 */
355 void statSampler_exit() {
356
357 if (!UsePerfData) return;
358
359 StatSampler::destroy();
360 }