1 /* 2 * Copyright (c) 1997, 2014, 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 #include "utilities/macros.hpp" 31 32 // The VM class loader. 33 #include <sys/stat.h> 34 35 36 // Meta-index (optional, to be able to skip opening boot classpath jar files) 37 class MetaIndex: public CHeapObj<mtClass> { 38 private: 39 char** _meta_package_names; 40 int _num_meta_package_names; 41 public: 42 MetaIndex(char** meta_package_names, int num_meta_package_names); 43 ~MetaIndex(); 44 bool may_contain(const char* class_name); 45 }; 46 47 48 // Class path entry (directory or zip file) 49 50 class ClassPathEntry: public CHeapObj<mtClass> { 51 private: 52 ClassPathEntry* _next; 53 public: 54 // Next entry in class path 55 ClassPathEntry* next() { return _next; } 56 void set_next(ClassPathEntry* next) { 57 // may have unlocked readers, so write atomically. 58 OrderAccess::release_store_ptr(&_next, next); 59 } 60 virtual bool is_jar_file() = 0; 61 virtual const char* name() = 0; 62 virtual bool is_lazy(); 63 // Constructor 64 ClassPathEntry(); 65 // Attempt to locate file_name through this class path entry. 66 // Returns a class file parsing stream if successfull. 67 virtual ClassFileStream* open_stream(const char* name, TRAPS) = 0; 68 // Debugging 69 NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;) 70 NOT_PRODUCT(virtual bool is_jrt() = 0;) 71 }; 72 73 74 class ClassPathDirEntry: public ClassPathEntry { 75 private: 76 const char* _dir; // Name of directory 77 public: 78 bool is_jar_file() { return false; } 79 const char* name() { return _dir; } 80 ClassPathDirEntry(const char* dir); 81 ClassFileStream* open_stream(const char* name, TRAPS); 82 // Debugging 83 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 84 NOT_PRODUCT(bool is_jrt();) 85 }; 86 87 88 // Type definitions for zip file and zip file entry 89 typedef void* jzfile; 90 typedef struct { 91 char *name; /* entry name */ 92 jlong time; /* modification time */ 93 jlong size; /* size of uncompressed data */ 94 jlong csize; /* size of compressed data (zero if uncompressed) */ 95 jint crc; /* crc of uncompressed data */ 96 char *comment; /* optional zip file comment */ 97 jbyte *extra; /* optional extra data */ 98 jlong pos; /* position of LOC header (if negative) or data */ 99 } jzentry; 100 101 102 class ClassPathZipEntry: public ClassPathEntry { 103 private: 104 jzfile* _zip; // The zip archive 105 const char* _zip_name; // Name of zip archive 106 public: 107 bool is_jar_file() { return true; } 108 const char* name() { return _zip_name; } 109 ClassPathZipEntry(jzfile* zip, const char* zip_name); 110 ~ClassPathZipEntry(); 111 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS); 112 ClassFileStream* open_stream(const char* name, TRAPS); 113 void contents_do(void f(const char* name, void* context), void* context); 114 // Debugging 115 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 116 NOT_PRODUCT(bool is_jrt();) 117 }; 118 119 120 // For lazier loading of boot class path entries 121 class LazyClassPathEntry: public ClassPathEntry { 122 private: 123 const char* _path; // dir or file 124 struct stat _st; 125 MetaIndex* _meta_index; 126 bool _has_error; 127 bool _throw_exception; 128 volatile ClassPathEntry* _resolved_entry; 129 ClassPathEntry* resolve_entry(TRAPS); 130 public: 131 bool is_jar_file(); 132 const char* name() { return _path; } 133 LazyClassPathEntry(const char* path, const struct stat* st, bool throw_exception); 134 virtual ~LazyClassPathEntry(); 135 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS); 136 137 ClassFileStream* open_stream(const char* name, TRAPS); 138 void set_meta_index(MetaIndex* meta_index) { _meta_index = meta_index; } 139 virtual bool is_lazy(); 140 // Debugging 141 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 142 NOT_PRODUCT(bool is_jrt();) 143 }; 144 145 // For java image files 146 class ImageFile; 147 class ClassPathImageEntry: public ClassPathEntry { 148 private: 149 ImageFile *_image; 150 public: 151 bool is_jar_file() { return false; } 152 bool is_open() { return _image != NULL; } 153 const char* name(); 154 ClassPathImageEntry(char* name); 155 ~ClassPathImageEntry(); 156 ClassFileStream* open_stream(const char* name, TRAPS); 157 158 // Debugging 159 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 160 NOT_PRODUCT(bool is_jrt();) 161 }; 162 163 class PackageHashtable; 164 class PackageInfo; 165 class SharedPathsMiscInfo; 166 template <MEMFLAGS F> class HashtableBucket; 167 168 class ClassLoader: AllStatic { 169 public: 170 enum SomeConstants { 171 package_hash_table_size = 31 // Number of buckets 172 }; 173 protected: 174 friend class LazyClassPathEntry; 175 176 // Performance counters 177 static PerfCounter* _perf_accumulated_time; 178 static PerfCounter* _perf_classes_inited; 179 static PerfCounter* _perf_class_init_time; 180 static PerfCounter* _perf_class_init_selftime; 181 static PerfCounter* _perf_classes_verified; 182 static PerfCounter* _perf_class_verify_time; 183 static PerfCounter* _perf_class_verify_selftime; 184 static PerfCounter* _perf_classes_linked; 185 static PerfCounter* _perf_class_link_time; 186 static PerfCounter* _perf_class_link_selftime; 187 static PerfCounter* _perf_class_parse_time; 188 static PerfCounter* _perf_class_parse_selftime; 189 static PerfCounter* _perf_sys_class_lookup_time; 190 static PerfCounter* _perf_shared_classload_time; 191 static PerfCounter* _perf_sys_classload_time; 192 static PerfCounter* _perf_app_classload_time; 193 static PerfCounter* _perf_app_classload_selftime; 194 static PerfCounter* _perf_app_classload_count; 195 static PerfCounter* _perf_define_appclasses; 196 static PerfCounter* _perf_define_appclass_time; 197 static PerfCounter* _perf_define_appclass_selftime; 198 static PerfCounter* _perf_app_classfile_bytes_read; 199 static PerfCounter* _perf_sys_classfile_bytes_read; 200 201 static PerfCounter* _sync_systemLoaderLockContentionRate; 202 static PerfCounter* _sync_nonSystemLoaderLockContentionRate; 203 static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter; 204 static PerfCounter* _sync_JVMDefineClassLockFreeCounter; 205 static PerfCounter* _sync_JNIDefineClassLockFreeCounter; 206 207 static PerfCounter* _unsafe_defineClassCallCounter; 208 static PerfCounter* _isUnsyncloadClass; 209 static PerfCounter* _load_instance_class_failCounter; 210 211 // First entry in linked list of ClassPathEntry instances 212 static ClassPathEntry* _first_entry; 213 // Last entry in linked list of ClassPathEntry instances 214 static ClassPathEntry* _last_entry; 215 static int _num_entries; 216 217 // Hash table used to keep track of loaded packages 218 static PackageHashtable* _package_hash_table; 219 static const char* _shared_archive; 220 221 // Info used by CDS 222 CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;) 223 224 // Hash function 225 static unsigned int hash(const char *s, int n); 226 // Returns the package file name corresponding to the specified package 227 // or class name, or null if not found. 228 static PackageInfo* lookup_package(const char *pkgname); 229 // Adds a new package entry for the specified class or package name and 230 // corresponding directory or jar file name. 231 static bool add_package(const char *pkgname, int classpath_index, TRAPS); 232 233 // Initialization 234 static void setup_bootstrap_meta_index(); 235 static void setup_meta_index(const char* meta_index_path, const char* meta_index_dir, 236 int start_index); 237 static void setup_bootstrap_search_path(); 238 static void setup_search_path(const char *class_path); 239 240 static void load_zip_library(); 241 static ClassPathEntry* create_class_path_entry(const char *path, const struct stat* st, 242 bool lazy, bool throw_exception, TRAPS); 243 244 // Canonicalizes path names, so strcmp will work properly. This is mainly 245 // to avoid confusing the zip library 246 static bool get_canonical_path(const char* orig, char* out, int len); 247 public: 248 static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg); 249 static int crc32(int crc, const char* buf, int len); 250 static bool update_class_path_entry_list(const char *path, 251 bool check_for_duplicates, 252 bool throw_exception=true); 253 static void print_bootclasspath(); 254 255 // Timing 256 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; } 257 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; } 258 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; } 259 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; } 260 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; } 261 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; } 262 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; } 263 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; } 264 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; } 265 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; } 266 static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; } 267 static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; } 268 static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; } 269 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; } 270 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; } 271 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; } 272 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; } 273 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; } 274 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; } 275 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; } 276 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; } 277 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; } 278 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; } 279 280 // Record how often system loader lock object is contended 281 static PerfCounter* sync_systemLoaderLockContentionRate() { 282 return _sync_systemLoaderLockContentionRate; 283 } 284 285 // Record how often non system loader lock object is contended 286 static PerfCounter* sync_nonSystemLoaderLockContentionRate() { 287 return _sync_nonSystemLoaderLockContentionRate; 288 } 289 290 // Record how many calls to JVM_FindLoadedClass w/o holding a lock 291 static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() { 292 return _sync_JVMFindLoadedClassLockFreeCounter; 293 } 294 295 // Record how many calls to JVM_DefineClass w/o holding a lock 296 static PerfCounter* sync_JVMDefineClassLockFreeCounter() { 297 return _sync_JVMDefineClassLockFreeCounter; 298 } 299 300 // Record how many calls to jni_DefineClass w/o holding a lock 301 static PerfCounter* sync_JNIDefineClassLockFreeCounter() { 302 return _sync_JNIDefineClassLockFreeCounter; 303 } 304 305 // Record how many calls to Unsafe_DefineClass 306 static PerfCounter* unsafe_defineClassCallCounter() { 307 return _unsafe_defineClassCallCounter; 308 } 309 310 // Record how many times SystemDictionary::load_instance_class call 311 // fails with linkageError when Unsyncloadclass flag is set. 312 static PerfCounter* load_instance_class_failCounter() { 313 return _load_instance_class_failCounter; 314 } 315 316 // Load individual .class file 317 static instanceKlassHandle load_classfile(Symbol* h_name, TRAPS); 318 319 // If the specified package has been loaded by the system, then returns 320 // the name of the directory or ZIP file that the package was loaded from. 321 // Returns null if the package was not loaded. 322 // Note: The specified name can either be the name of a class or package. 323 // If a package name is specified, then it must be "/"-separator and also 324 // end with a trailing "/". 325 static oop get_system_package(const char* name, TRAPS); 326 327 // Returns an array of Java strings representing all of the currently 328 // loaded system packages. 329 // Note: The package names returned are "/"-separated and end with a 330 // trailing "/". 331 static objArrayOop get_system_packages(TRAPS); 332 333 // Initialization 334 static void initialize(); 335 CDS_ONLY(static void initialize_shared_path();) 336 static void create_package_info_table(); 337 static void create_package_info_table(HashtableBucket<mtClass> *t, int length, 338 int number_of_entries); 339 static int compute_Object_vtable(); 340 341 static ClassPathEntry* classpath_entry(int n) { 342 ClassPathEntry* e = ClassLoader::_first_entry; 343 while (--n >= 0) { 344 assert(e != NULL, "Not that many classpath entries."); 345 e = e->next(); 346 } 347 return e; 348 } 349 350 #if INCLUDE_CDS 351 // Sharing dump and restore 352 static void copy_package_info_buckets(char** top, char* end); 353 static void copy_package_info_table(char** top, char* end); 354 355 static void check_shared_classpath(const char *path); 356 static void finalize_shared_paths_misc_info(); 357 static int get_shared_paths_misc_info_size(); 358 static void* get_shared_paths_misc_info(); 359 static bool check_shared_paths_misc_info(void* info, int size); 360 static void exit_with_path_failure(const char* error, const char* message); 361 #endif 362 363 static void trace_class_path(const char* msg, const char* name = NULL); 364 365 // VM monitoring and management support 366 static jlong classloader_time_ms(); 367 static jlong class_method_total_size(); 368 static jlong class_init_count(); 369 static jlong class_init_time_ms(); 370 static jlong class_verify_time_ms(); 371 static jlong class_link_count(); 372 static jlong class_link_time_ms(); 373 374 // indicates if class path already contains a entry (exact match by name) 375 static bool contains_entry(ClassPathEntry* entry); 376 377 // adds a class path list 378 static void add_to_list(ClassPathEntry* new_entry); 379 380 // creates a class path zip entry (returns NULL if JAR file cannot be opened) 381 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath); 382 383 // Debugging 384 static void verify() PRODUCT_RETURN; 385 386 // Force compilation of all methods in all classes in bootstrap class path (stress test) 387 #ifndef PRODUCT 388 protected: 389 static int _compile_the_world_class_counter; 390 static int _compile_the_world_method_counter; 391 public: 392 static void compile_the_world(); 393 static void compile_the_world_in(char* name, Handle loader, TRAPS); 394 static int compile_the_world_counter() { return _compile_the_world_class_counter; } 395 #endif //PRODUCT 396 }; 397 398 // PerfClassTraceTime is used to measure time for class loading related events. 399 // This class tracks cumulative time and exclusive time for specific event types. 400 // During the execution of one event, other event types (e.g. class loading and 401 // resolution) as well as recursive calls of the same event type could happen. 402 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive) 403 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime 404 // instances have been created as multiple events are happening. 405 class PerfClassTraceTime { 406 public: 407 enum { 408 CLASS_LOAD = 0, 409 PARSE_CLASS = 1, 410 CLASS_LINK = 2, 411 CLASS_VERIFY = 3, 412 CLASS_CLINIT = 4, 413 DEFINE_CLASS = 5, 414 EVENT_TYPE_COUNT = 6 415 }; 416 protected: 417 // _t tracks time from initialization to destruction of this timer instance 418 // including time for all other event types, and recursive calls of this type. 419 // When a timer is called recursively, the elapsedTimer _t would not be used. 420 elapsedTimer _t; 421 PerfLongCounter* _timep; 422 PerfLongCounter* _selftimep; 423 PerfLongCounter* _eventp; 424 // pointer to thread-local recursion counter and timer array 425 // The thread_local timers track cumulative time for specific event types 426 // exclusive of time for other event types, but including recursive calls 427 // of the same type. 428 int* _recursion_counters; 429 elapsedTimer* _timers; 430 int _event_type; 431 int _prev_active_event; 432 433 public: 434 435 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ 436 PerfLongCounter* selftimep, /* counter incremented with exclusive time */ 437 PerfLongCounter* eventp, /* event counter */ 438 int* recursion_counters, /* thread-local recursion counter array */ 439 elapsedTimer* timers, /* thread-local timer array */ 440 int type /* event type */ ) : 441 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) { 442 initialize(); 443 } 444 445 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ 446 elapsedTimer* timers, /* thread-local timer array */ 447 int type /* event type */ ) : 448 _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) { 449 initialize(); 450 } 451 452 inline void suspend() { _t.stop(); _timers[_event_type].stop(); } 453 inline void resume() { _t.start(); _timers[_event_type].start(); } 454 455 ~PerfClassTraceTime(); 456 void initialize(); 457 }; 458 459 #endif // SHARE_VM_CLASSFILE_CLASSLOADER_HPP