statSampler.cpp revision 1472:c18cbe5936b8
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 31class 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 41StatSamplerTask* StatSampler::_task = NULL; 42PerfDataList* 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 */ 48void 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 */ 67void 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 */ 88void 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 */ 110void 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 */ 124void 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 */ 144void 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 */ 170const 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 208static 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 226static const char* property_counters_us[] = { 227 NULL 228}; 229 230// unstable interface, unsupported counters 231static const char* property_counters_uu[] = { 232 "sun.boot.class.path", 233 "sun.boot.library.path", 234 NULL 235}; 236 237typedef struct { 238 const char** property_list; 239 CounterNS name_space; 240} PropertyCounters; 241 242static 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 */ 257void 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 */ 287void 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 */ 329class 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 */ 339void 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 */ 355void statSampler_exit() { 356 357 if (!UsePerfData) return; 358 359 StatSampler::destroy(); 360} 361