1 /* 2 * Copyright (c) 1997, 2015, 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 // Class path entry (directory or zip file) 37 38 class ClassPathEntry: public CHeapObj<mtClass> { 39 private: 40 ClassPathEntry* _next; 41 public: 42 // Next entry in class path 43 ClassPathEntry* next() { return _next; } 44 void set_next(ClassPathEntry* next) { 45 // may have unlocked readers, so write atomically. 46 OrderAccess::release_store_ptr(&_next, next); 47 } 48 virtual bool is_jar_file() = 0; 49 virtual const char* name() = 0; 50 virtual bool is_lazy(); 51 // Constructor 52 ClassPathEntry(); 53 // Attempt to locate file_name through this class path entry. 54 // Returns a class file parsing stream if successfull. 55 virtual ClassFileStream* open_stream(const char* name, TRAPS) = 0; 56 // Debugging 57 NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;) 58 NOT_PRODUCT(virtual bool is_jrt() = 0;) 59 }; 60 61 62 class ClassPathDirEntry: public ClassPathEntry { 63 private: 64 const char* _dir; // Name of directory 65 public: 66 bool is_jar_file() { return false; } 67 const char* name() { return _dir; } 68 ClassPathDirEntry(const char* dir); 69 ClassFileStream* open_stream(const char* name, TRAPS); 70 // Debugging 71 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 72 NOT_PRODUCT(bool is_jrt();) 73 }; 74 75 76 // Type definitions for zip file and zip file entry 77 typedef void* jzfile; 78 typedef struct { 79 char *name; /* entry name */ 80 jlong time; /* modification time */ 81 jlong size; /* size of uncompressed data */ 82 jlong csize; /* size of compressed data (zero if uncompressed) */ 83 jint crc; /* crc of uncompressed data */ 84 char *comment; /* optional zip file comment */ 85 jbyte *extra; /* optional extra data */ 86 jlong pos; /* position of LOC header (if negative) or data */ 87 } jzentry; 88 89 90 class ClassPathZipEntry: public ClassPathEntry { 91 private: 92 jzfile* _zip; // The zip archive 93 const char* _zip_name; // Name of zip archive 94 public: 95 bool is_jar_file() { return true; } 96 const char* name() { return _zip_name; } 97 ClassPathZipEntry(jzfile* zip, const char* zip_name); 98 ~ClassPathZipEntry(); 99 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS); 100 ClassFileStream* open_stream(const char* name, TRAPS); 101 void contents_do(void f(const char* name, void* context), void* context); 102 // Debugging 103 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 104 NOT_PRODUCT(bool is_jrt();) 105 }; 106 107 108 // For lazier loading of boot class path entries 109 class LazyClassPathEntry: public ClassPathEntry { 110 private: 111 const char* _path; // dir or file 112 struct stat _st; 113 bool _has_error; 114 bool _throw_exception; 115 volatile ClassPathEntry* _resolved_entry; 116 ClassPathEntry* resolve_entry(TRAPS); 117 public: 118 bool is_jar_file(); 119 const char* name() { return _path; } 120 LazyClassPathEntry(const char* path, const struct stat* st, bool throw_exception); 121 virtual ~LazyClassPathEntry(); 122 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS); 123 124 ClassFileStream* open_stream(const char* name, TRAPS); 125 virtual bool is_lazy(); 126 // Debugging 127 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 128 NOT_PRODUCT(bool is_jrt();) 129 }; 130 131 // For java image files 132 class ImageFile; 133 class ClassPathImageEntry: public ClassPathEntry { 134 private: 135 ImageFile *_image; 136 public: 137 bool is_jar_file() { return false; } 138 bool is_open() { return _image != NULL; } 139 const char* name(); 140 ClassPathImageEntry(char* name); 141 ~ClassPathImageEntry(); 142 ClassFileStream* open_stream(const char* name, TRAPS); 143 144 // Debugging 145 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 146 NOT_PRODUCT(bool is_jrt();) 147 }; 148 149 class PackageHashtable; 150 class PackageInfo; 151 class SharedPathsMiscInfo; 152 template <MEMFLAGS F> class HashtableBucket; 153 154 class ClassLoader: AllStatic { 155 public: 156 enum SomeConstants { 157 package_hash_table_size = 31 // Number of buckets 158 }; 159 protected: 160 friend class LazyClassPathEntry; 161 162 // Performance counters 163 static PerfCounter* _perf_accumulated_time; 164 static PerfCounter* _perf_classes_inited; 165 static PerfCounter* _perf_class_init_time; 166 static PerfCounter* _perf_class_init_selftime; 167 static PerfCounter* _perf_classes_verified; 168 static PerfCounter* _perf_class_verify_time; 169 static PerfCounter* _perf_class_verify_selftime; 170 static PerfCounter* _perf_classes_linked; 171 static PerfCounter* _perf_class_link_time; 172 static PerfCounter* _perf_class_link_selftime; 173 static PerfCounter* _perf_class_parse_time; 174 static PerfCounter* _perf_class_parse_selftime; 175 static PerfCounter* _perf_sys_class_lookup_time; 176 static PerfCounter* _perf_shared_classload_time; 177 static PerfCounter* _perf_sys_classload_time; 178 static PerfCounter* _perf_app_classload_time; 179 static PerfCounter* _perf_app_classload_selftime; 180 static PerfCounter* _perf_app_classload_count; 181 static PerfCounter* _perf_define_appclasses; 182 static PerfCounter* _perf_define_appclass_time; 183 static PerfCounter* _perf_define_appclass_selftime; 184 static PerfCounter* _perf_app_classfile_bytes_read; 185 static PerfCounter* _perf_sys_classfile_bytes_read; 186 187 static PerfCounter* _sync_systemLoaderLockContentionRate; 188 static PerfCounter* _sync_nonSystemLoaderLockContentionRate; 189 static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter; 190 static PerfCounter* _sync_JVMDefineClassLockFreeCounter; 191 static PerfCounter* _sync_JNIDefineClassLockFreeCounter; 192 193 static PerfCounter* _unsafe_defineClassCallCounter; 194 static PerfCounter* _isUnsyncloadClass; 195 static PerfCounter* _load_instance_class_failCounter; 196 197 // First entry in linked list of ClassPathEntry instances 198 static ClassPathEntry* _first_entry; 199 // Last entry in linked list of ClassPathEntry instances 200 static ClassPathEntry* _last_entry; 201 static int _num_entries; 202 203 // Hash table used to keep track of loaded packages 204 static PackageHashtable* _package_hash_table; 205 static const char* _shared_archive; 206 207 // Info used by CDS 208 CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;) 209 210 // Hash function 211 static unsigned int hash(const char *s, int n); 212 // Returns the package file name corresponding to the specified package 213 // or class name, or null if not found. 214 static PackageInfo* lookup_package(const char *pkgname); 215 // Adds a new package entry for the specified class or package name and 216 // corresponding directory or jar file name. 217 static bool add_package(const char *pkgname, int classpath_index, TRAPS); 218 219 // Initialization 220 static void setup_bootstrap_search_path(); 221 static void setup_search_path(const char *class_path); 222 223 static void load_zip_library(); 224 static ClassPathEntry* create_class_path_entry(const char *path, const struct stat* st, 225 bool lazy, bool throw_exception, TRAPS); 226 227 // Canonicalizes path names, so strcmp will work properly. This is mainly 228 // to avoid confusing the zip library 229 static bool get_canonical_path(const char* orig, char* out, int len); 230 public: 231 static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg); 232 static int crc32(int crc, const char* buf, int len); 233 static bool update_class_path_entry_list(const char *path, 234 bool check_for_duplicates, 235 bool throw_exception=true); 236 static void print_bootclasspath(); 237 238 // Timing 239 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; } 240 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; } 241 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; } 242 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; } 243 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; } 244 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; } 245 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; } 246 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; } 247 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; } 248 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; } 249 static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; } 250 static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; } 251 static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; } 252 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; } 253 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; } 254 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; } 255 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; } 256 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; } 257 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; } 258 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; } 259 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; } 260 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; } 261 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; } 262 263 // Record how often system loader lock object is contended 264 static PerfCounter* sync_systemLoaderLockContentionRate() { 265 return _sync_systemLoaderLockContentionRate; 266 } 267 268 // Record how often non system loader lock object is contended 269 static PerfCounter* sync_nonSystemLoaderLockContentionRate() { 270 return _sync_nonSystemLoaderLockContentionRate; 271 } 272 273 // Record how many calls to JVM_FindLoadedClass w/o holding a lock 274 static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() { 275 return _sync_JVMFindLoadedClassLockFreeCounter; 276 } 277 278 // Record how many calls to JVM_DefineClass w/o holding a lock 279 static PerfCounter* sync_JVMDefineClassLockFreeCounter() { 280 return _sync_JVMDefineClassLockFreeCounter; 281 } 282 283 // Record how many calls to jni_DefineClass w/o holding a lock 284 static PerfCounter* sync_JNIDefineClassLockFreeCounter() { 285 return _sync_JNIDefineClassLockFreeCounter; 286 } 287 288 // Record how many calls to Unsafe_DefineClass 289 static PerfCounter* unsafe_defineClassCallCounter() { 290 return _unsafe_defineClassCallCounter; 291 } 292 293 // Record how many times SystemDictionary::load_instance_class call 294 // fails with linkageError when Unsyncloadclass flag is set. 295 static PerfCounter* load_instance_class_failCounter() { 296 return _load_instance_class_failCounter; 297 } 298 299 // Load individual .class file 300 static instanceKlassHandle load_classfile(Symbol* h_name, TRAPS); 301 302 // If the specified package has been loaded by the system, then returns 303 // the name of the directory or ZIP file that the package was loaded from. 304 // Returns null if the package was not loaded. 305 // Note: The specified name can either be the name of a class or package. 306 // If a package name is specified, then it must be "/"-separator and also 307 // end with a trailing "/". 308 static oop get_system_package(const char* name, TRAPS); 309 310 // Returns an array of Java strings representing all of the currently 311 // loaded system packages. 312 // Note: The package names returned are "/"-separated and end with a 313 // trailing "/". 314 static objArrayOop get_system_packages(TRAPS); 315 316 // Initialization 317 static void initialize(); 318 CDS_ONLY(static void initialize_shared_path();) 319 static void create_package_info_table(); 320 static void create_package_info_table(HashtableBucket<mtClass> *t, int length, 321 int number_of_entries); 322 static int compute_Object_vtable(); 323 324 static ClassPathEntry* classpath_entry(int n) { 325 ClassPathEntry* e = ClassLoader::_first_entry; 326 while (--n >= 0) { 327 assert(e != NULL, "Not that many classpath entries."); 328 e = e->next(); 329 } 330 return e; 331 } 332 333 #if INCLUDE_CDS 334 // Sharing dump and restore 335 static void copy_package_info_buckets(char** top, char* end); 336 static void copy_package_info_table(char** top, char* end); 337 338 static void check_shared_classpath(const char *path); 339 static void finalize_shared_paths_misc_info(); 340 static int get_shared_paths_misc_info_size(); 341 static void* get_shared_paths_misc_info(); 342 static bool check_shared_paths_misc_info(void* info, int size); 343 static void exit_with_path_failure(const char* error, const char* message); 344 #endif 345 346 static void trace_class_path(const char* msg, const char* name = NULL); 347 348 // VM monitoring and management support 349 static jlong classloader_time_ms(); 350 static jlong class_method_total_size(); 351 static jlong class_init_count(); 352 static jlong class_init_time_ms(); 353 static jlong class_verify_time_ms(); 354 static jlong class_link_count(); 355 static jlong class_link_time_ms(); 356 357 // indicates if class path already contains a entry (exact match by name) 358 static bool contains_entry(ClassPathEntry* entry); 359 360 // adds a class path list 361 static void add_to_list(ClassPathEntry* new_entry); 362 363 // creates a class path zip entry (returns NULL if JAR file cannot be opened) 364 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath); 365 366 // Debugging 367 static void verify() PRODUCT_RETURN; 368 369 // Force compilation of all methods in all classes in bootstrap class path (stress test) 370 #ifndef PRODUCT 371 protected: 372 static int _compile_the_world_class_counter; 373 static int _compile_the_world_method_counter; 374 public: 375 static void compile_the_world(); 376 static void compile_the_world_in(char* name, Handle loader, TRAPS); 377 static int compile_the_world_counter() { return _compile_the_world_class_counter; } 378 #endif //PRODUCT 379 }; 380 381 // PerfClassTraceTime is used to measure time for class loading related events. 382 // This class tracks cumulative time and exclusive time for specific event types. 383 // During the execution of one event, other event types (e.g. class loading and 384 // resolution) as well as recursive calls of the same event type could happen. 385 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive) 386 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime 387 // instances have been created as multiple events are happening. 388 class PerfClassTraceTime { 389 public: 390 enum { 391 CLASS_LOAD = 0, 392 PARSE_CLASS = 1, 393 CLASS_LINK = 2, 394 CLASS_VERIFY = 3, 395 CLASS_CLINIT = 4, 396 DEFINE_CLASS = 5, 397 EVENT_TYPE_COUNT = 6 398 }; 399 protected: 400 // _t tracks time from initialization to destruction of this timer instance 401 // including time for all other event types, and recursive calls of this type. 402 // When a timer is called recursively, the elapsedTimer _t would not be used. 403 elapsedTimer _t; 404 PerfLongCounter* _timep; 405 PerfLongCounter* _selftimep; 406 PerfLongCounter* _eventp; 407 // pointer to thread-local recursion counter and timer array 408 // The thread_local timers track cumulative time for specific event types 409 // exclusive of time for other event types, but including recursive calls 410 // of the same type. 411 int* _recursion_counters; 412 elapsedTimer* _timers; 413 int _event_type; 414 int _prev_active_event; 415 416 public: 417 418 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ 419 PerfLongCounter* selftimep, /* counter incremented with exclusive time */ 420 PerfLongCounter* eventp, /* event counter */ 421 int* recursion_counters, /* thread-local recursion counter array */ 422 elapsedTimer* timers, /* thread-local timer array */ 423 int type /* event type */ ) : 424 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) { 425 initialize(); 426 } 427 428 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ 429 elapsedTimer* timers, /* thread-local timer array */ 430 int type /* event type */ ) : 431 _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) { 432 initialize(); 433 } 434 435 inline void suspend() { _t.stop(); _timers[_event_type].stop(); } 436 inline void resume() { _t.start(); _timers[_event_type].start(); } 437 438 ~PerfClassTraceTime(); 439 void initialize(); 440 }; 441 442 #endif // SHARE_VM_CLASSFILE_CLASSLOADER_HPP