1 /* 2 * Copyright (c) 1997, 2010, 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_CLASSFILE_CLASSLOADER_HPP 26 #define SHARE_VM_CLASSFILE_CLASSLOADER_HPP 27 28 #include "classfile/classFileParser.hpp" 29 #include "runtime/perfData.hpp" 30 31 // The VM class loader. 32 #include <sys/stat.h> 33 34 35 // Meta-index (optional, to be able to skip opening boot classpath jar files) 36 class MetaIndex: public CHeapObj { 37 private: 38 char** _meta_package_names; 39 int _num_meta_package_names; 40 public: 41 MetaIndex(char** meta_package_names, int num_meta_package_names); 42 ~MetaIndex(); 43 bool may_contain(const char* class_name); 44 }; 45 46 47 // Class path entry (directory or zip file) 48 49 class ClassPathEntry: public CHeapObj { 50 private: 51 ClassPathEntry* _next; 52 public: 53 // Next entry in class path 54 ClassPathEntry* next() { return _next; } 55 void set_next(ClassPathEntry* next) { 56 // may have unlocked readers, so write atomically. 57 OrderAccess::release_store_ptr(&_next, next); 58 } 59 virtual bool is_jar_file() = 0; 60 virtual const char* name() = 0; 61 virtual bool is_lazy(); 62 // Constructor 63 ClassPathEntry(); 64 // Attempt to locate file_name through this class path entry. 65 // Returns a class file parsing stream if successfull. 66 virtual ClassFileStream* open_stream(const char* name) = 0; 67 // Debugging 68 NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;) 69 NOT_PRODUCT(virtual bool is_rt_jar() = 0;) 70 }; 71 72 73 class ClassPathDirEntry: public ClassPathEntry { 74 private: 75 char* _dir; // Name of directory 76 public: 77 bool is_jar_file() { return false; } 78 const char* name() { return _dir; } 79 ClassPathDirEntry(char* dir); 80 ClassFileStream* open_stream(const char* name); 81 // Debugging 82 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 83 NOT_PRODUCT(bool is_rt_jar();) 84 }; 85 86 87 // Type definitions for zip file and zip file entry 88 typedef void* jzfile; 89 typedef struct { 90 char *name; /* entry name */ 91 jlong time; /* modification time */ 92 jlong size; /* size of uncompressed data */ 93 jlong csize; /* size of compressed data (zero if uncompressed) */ 94 jint crc; /* crc of uncompressed data */ 95 char *comment; /* optional zip file comment */ 96 jbyte *extra; /* optional extra data */ 97 jlong pos; /* position of LOC header (if negative) or data */ 98 } jzentry; 99 100 101 class ClassPathZipEntry: public ClassPathEntry { 102 private: 103 jzfile* _zip; // The zip archive 104 char* _zip_name; // Name of zip archive 105 public: 106 bool is_jar_file() { return true; } 107 const char* name() { return _zip_name; } 108 ClassPathZipEntry(jzfile* zip, const char* zip_name); 109 ~ClassPathZipEntry(); 110 ClassFileStream* open_stream(const char* name); 111 void contents_do(void f(const char* name, void* context), void* context); 112 // Debugging 113 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 114 NOT_PRODUCT(void compile_the_world12(Handle loader, TRAPS);) // JDK 1.2 version 115 NOT_PRODUCT(void compile_the_world13(Handle loader, TRAPS);) // JDK 1.3 version 116 NOT_PRODUCT(bool is_rt_jar();) 117 NOT_PRODUCT(bool is_rt_jar12();) 118 NOT_PRODUCT(bool is_rt_jar13();) 119 }; 120 121 122 // For lazier loading of boot class path entries 123 class LazyClassPathEntry: public ClassPathEntry { 124 private: 125 char* _path; // dir or file 126 struct stat _st; 127 MetaIndex* _meta_index; 128 volatile ClassPathEntry* _resolved_entry; 129 ClassPathEntry* resolve_entry(); 130 public: 131 bool is_jar_file(); 132 const char* name() { return _path; } 133 LazyClassPathEntry(char* path, struct stat st); 134 ClassFileStream* open_stream(const char* name); 135 void set_meta_index(MetaIndex* meta_index) { _meta_index = meta_index; } 136 virtual bool is_lazy(); 137 // Debugging 138 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 139 NOT_PRODUCT(bool is_rt_jar();) 140 }; 141 142 class PackageHashtable; 143 class PackageInfo; 144 class HashtableBucket; 145 146 class ClassLoader: AllStatic { 147 public: 148 enum SomeConstants { 149 package_hash_table_size = 31 // Number of buckets 150 }; 151 private: 152 friend class LazyClassPathEntry; 153 154 // Performance counters 155 static PerfCounter* _perf_accumulated_time; 156 static PerfCounter* _perf_classes_inited; 157 static PerfCounter* _perf_class_init_time; 158 static PerfCounter* _perf_class_init_selftime; 159 static PerfCounter* _perf_classes_verified; 160 static PerfCounter* _perf_class_verify_time; 161 static PerfCounter* _perf_class_verify_selftime; 162 static PerfCounter* _perf_classes_linked; 163 static PerfCounter* _perf_class_link_time; 164 static PerfCounter* _perf_class_link_selftime; 165 static PerfCounter* _perf_class_parse_time; 166 static PerfCounter* _perf_class_parse_selftime; 167 static PerfCounter* _perf_sys_class_lookup_time; 168 static PerfCounter* _perf_shared_classload_time; 169 static PerfCounter* _perf_sys_classload_time; 170 static PerfCounter* _perf_app_classload_time; 171 static PerfCounter* _perf_app_classload_selftime; 172 static PerfCounter* _perf_app_classload_count; 173 static PerfCounter* _perf_define_appclasses; 174 static PerfCounter* _perf_define_appclass_time; 175 static PerfCounter* _perf_define_appclass_selftime; 176 static PerfCounter* _perf_app_classfile_bytes_read; 177 static PerfCounter* _perf_sys_classfile_bytes_read; 178 179 static PerfCounter* _sync_systemLoaderLockContentionRate; 180 static PerfCounter* _sync_nonSystemLoaderLockContentionRate; 181 static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter; 182 static PerfCounter* _sync_JVMDefineClassLockFreeCounter; 183 static PerfCounter* _sync_JNIDefineClassLockFreeCounter; 184 185 static PerfCounter* _unsafe_defineClassCallCounter; 186 static PerfCounter* _isUnsyncloadClass; 187 static PerfCounter* _load_instance_class_failCounter; 188 189 // First entry in linked list of ClassPathEntry instances 190 static ClassPathEntry* _first_entry; 191 // Last entry in linked list of ClassPathEntry instances 192 static ClassPathEntry* _last_entry; 193 // Hash table used to keep track of loaded packages 194 static PackageHashtable* _package_hash_table; 195 static const char* _shared_archive; 196 197 // Hash function 198 static unsigned int hash(const char *s, int n); 199 // Returns the package file name corresponding to the specified package 200 // or class name, or null if not found. 201 static PackageInfo* lookup_package(const char *pkgname); 202 // Adds a new package entry for the specified class or package name and 203 // corresponding directory or jar file name. 204 static bool add_package(const char *pkgname, int classpath_index, TRAPS); 205 206 // Initialization 207 static void setup_meta_index(); 208 static void setup_bootstrap_search_path(); 209 static void load_zip_library(); 210 static void create_class_path_entry(char *path, struct stat st, ClassPathEntry **new_entry, bool lazy); 211 212 // Canonicalizes path names, so strcmp will work properly. This is mainly 213 // to avoid confusing the zip library 214 static bool get_canonical_path(char* orig, char* out, int len); 215 public: 216 // Used by the kernel jvm. 217 static void update_class_path_entry_list(const char *path, 218 bool check_for_duplicates); 219 static void print_bootclasspath(); 220 221 // Timing 222 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; } 223 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; } 224 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; } 225 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; } 226 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; } 227 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; } 228 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; } 229 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; } 230 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; } 231 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; } 232 static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; } 233 static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; } 234 static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; } 235 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; } 236 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; } 237 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; } 238 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; } 239 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; } 240 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; } 241 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; } 242 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; } 243 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; } 244 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; } 245 246 // Record how often system loader lock object is contended 247 static PerfCounter* sync_systemLoaderLockContentionRate() { 248 return _sync_systemLoaderLockContentionRate; 249 } 250 251 // Record how often non system loader lock object is contended 252 static PerfCounter* sync_nonSystemLoaderLockContentionRate() { 253 return _sync_nonSystemLoaderLockContentionRate; 254 } 255 256 // Record how many calls to JVM_FindLoadedClass w/o holding a lock 257 static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() { 258 return _sync_JVMFindLoadedClassLockFreeCounter; 259 } 260 261 // Record how many calls to JVM_DefineClass w/o holding a lock 262 static PerfCounter* sync_JVMDefineClassLockFreeCounter() { 263 return _sync_JVMDefineClassLockFreeCounter; 264 } 265 266 // Record how many calls to jni_DefineClass w/o holding a lock 267 static PerfCounter* sync_JNIDefineClassLockFreeCounter() { 268 return _sync_JNIDefineClassLockFreeCounter; 269 } 270 271 // Record how many calls to Unsafe_DefineClass 272 static PerfCounter* unsafe_defineClassCallCounter() { 273 return _unsafe_defineClassCallCounter; 274 } 275 276 // Record how many times SystemDictionary::load_instance_class call 277 // fails with linkageError when Unsyncloadclass flag is set. 278 static PerfCounter* load_instance_class_failCounter() { 279 return _load_instance_class_failCounter; 280 } 281 282 // Load individual .class file 283 static instanceKlassHandle load_classfile(symbolHandle h_name, TRAPS); 284 285 // If the specified package has been loaded by the system, then returns 286 // the name of the directory or ZIP file that the package was loaded from. 287 // Returns null if the package was not loaded. 288 // Note: The specified name can either be the name of a class or package. 289 // If a package name is specified, then it must be "/"-separator and also 290 // end with a trailing "/". 291 static oop get_system_package(const char* name, TRAPS); 292 293 // Returns an array of Java strings representing all of the currently 294 // loaded system packages. 295 // Note: The package names returned are "/"-separated and end with a 296 // trailing "/". 297 static objArrayOop get_system_packages(TRAPS); 298 299 // Initialization 300 static void initialize(); 301 static void create_package_info_table(); 302 static void create_package_info_table(HashtableBucket *t, int length, 303 int number_of_entries); 304 static int compute_Object_vtable(); 305 306 static ClassPathEntry* classpath_entry(int n) { 307 ClassPathEntry* e = ClassLoader::_first_entry; 308 while (--n >= 0) { 309 assert(e != NULL, "Not that many classpath entries."); 310 e = e->next(); 311 } 312 return e; 313 } 314 315 // Sharing dump and restore 316 static void copy_package_info_buckets(char** top, char* end); 317 static void copy_package_info_table(char** top, char* end); 318 319 // VM monitoring and management support 320 static jlong classloader_time_ms(); 321 static jlong class_method_total_size(); 322 static jlong class_init_count(); 323 static jlong class_init_time_ms(); 324 static jlong class_verify_time_ms(); 325 static jlong class_link_count(); 326 static jlong class_link_time_ms(); 327 328 // indicates if class path already contains a entry (exact match by name) 329 static bool contains_entry(ClassPathEntry* entry); 330 331 // adds a class path list 332 static void add_to_list(ClassPathEntry* new_entry); 333 334 // creates a class path zip entry (returns NULL if JAR file cannot be opened) 335 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath); 336 337 // Debugging 338 static void verify() PRODUCT_RETURN; 339 340 // Force compilation of all methods in all classes in bootstrap class path (stress test) 341 #ifndef PRODUCT 342 private: 343 static int _compile_the_world_counter; 344 public: 345 static void compile_the_world(); 346 static void compile_the_world_in(char* name, Handle loader, TRAPS); 347 static int compile_the_world_counter() { return _compile_the_world_counter; } 348 #endif //PRODUCT 349 }; 350 351 // PerfClassTraceTime is used to measure time for class loading related events. 352 // This class tracks cumulative time and exclusive time for specific event types. 353 // During the execution of one event, other event types (e.g. class loading and 354 // resolution) as well as recursive calls of the same event type could happen. 355 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive) 356 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime 357 // instances have been created as multiple events are happening. 358 class PerfClassTraceTime { 359 public: 360 enum { 361 CLASS_LOAD = 0, 362 PARSE_CLASS = 1, 363 CLASS_LINK = 2, 364 CLASS_VERIFY = 3, 365 CLASS_CLINIT = 4, 366 DEFINE_CLASS = 5, 367 EVENT_TYPE_COUNT = 6 368 }; 369 protected: 370 // _t tracks time from initialization to destruction of this timer instance 371 // including time for all other event types, and recursive calls of this type. 372 // When a timer is called recursively, the elapsedTimer _t would not be used. 373 elapsedTimer _t; 374 PerfLongCounter* _timep; 375 PerfLongCounter* _selftimep; 376 PerfLongCounter* _eventp; 377 // pointer to thread-local recursion counter and timer array 378 // The thread_local timers track cumulative time for specific event types 379 // exclusive of time for other event types, but including recursive calls 380 // of the same type. 381 int* _recursion_counters; 382 elapsedTimer* _timers; 383 int _event_type; 384 int _prev_active_event; 385 386 public: 387 388 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ 389 PerfLongCounter* selftimep, /* counter incremented with exclusive time */ 390 PerfLongCounter* eventp, /* event counter */ 391 int* recursion_counters, /* thread-local recursion counter array */ 392 elapsedTimer* timers, /* thread-local timer array */ 393 int type /* event type */ ) : 394 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) { 395 initialize(); 396 } 397 398 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ 399 elapsedTimer* timers, /* thread-local timer array */ 400 int type /* event type */ ) : 401 _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) { 402 initialize(); 403 } 404 405 void initialize() { 406 if (!UsePerfData) return; 407 408 if (_eventp != NULL) { 409 // increment the event counter 410 _eventp->inc(); 411 } 412 413 // stop the current active thread-local timer to measure inclusive time 414 _prev_active_event = -1; 415 for (int i=0; i < EVENT_TYPE_COUNT; i++) { 416 if (_timers[i].is_active()) { 417 assert(_prev_active_event == -1, "should have only one active timer"); 418 _prev_active_event = i; 419 _timers[i].stop(); 420 } 421 } 422 423 if (_recursion_counters == NULL || (_recursion_counters[_event_type])++ == 0) { 424 // start the inclusive timer if not recursively called 425 _t.start(); 426 } 427 428 // start thread-local timer of the given event type 429 if (!_timers[_event_type].is_active()) { 430 _timers[_event_type].start(); 431 } 432 } 433 434 inline void suspend() { _t.stop(); _timers[_event_type].stop(); } 435 inline void resume() { _t.start(); _timers[_event_type].start(); } 436 437 ~PerfClassTraceTime() { 438 if (!UsePerfData) return; 439 440 // stop the thread-local timer as the event completes 441 // and resume the thread-local timer of the event next on the stack 442 _timers[_event_type].stop(); 443 jlong selftime = _timers[_event_type].ticks(); 444 445 if (_prev_active_event >= 0) { 446 _timers[_prev_active_event].start(); 447 } 448 449 if (_recursion_counters != NULL && --(_recursion_counters[_event_type]) > 0) return; 450 451 // increment the counters only on the leaf call 452 _t.stop(); 453 _timep->inc(_t.ticks()); 454 if (_selftimep != NULL) { 455 _selftimep->inc(selftime); 456 } 457 // add all class loading related event selftime to the accumulated time counter 458 ClassLoader::perf_accumulated_time()->inc(selftime); 459 460 // reset the timer 461 _timers[_event_type].reset(); 462 } 463 }; 464 465 466 #endif // SHARE_VM_CLASSFILE_CLASSLOADER_HPP