1 /* 2 * Copyright (c) 1997, 2016, 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 "runtime/orderAccess.hpp" 29 #include "runtime/perfData.hpp" 30 #include "utilities/exceptions.hpp" 31 #include "utilities/macros.hpp" 32 33 // The VM class loader. 34 #include <sys/stat.h> 35 36 // Name of boot "modules" image 37 #define MODULES_IMAGE_NAME "modules" 38 39 // Name of the resource containing mapping from module names to defining class loader type 40 #define MODULE_LOADER_MAP "jdk/internal/vm/cds/resources/ModuleLoaderMap.dat" 41 42 // Initial sizes of the following arrays are based on the generated ModuleLoaderMap.dat 43 #define INITIAL_BOOT_MODULES_ARRAY_SIZE 30 44 #define INITIAL_PLATFORM_MODULES_ARRAY_SIZE 15 45 46 // Class path entry (directory or zip file) 47 48 class JImageFile; 49 class ClassFileStream; 50 51 class ClassPathEntry : public CHeapObj<mtClass> { 52 private: 53 ClassPathEntry* _next; 54 public: 55 // Next entry in class path 56 ClassPathEntry* next() const { return _next; } 57 void set_next(ClassPathEntry* next) { 58 // may have unlocked readers, so write atomically. 59 OrderAccess::release_store_ptr(&_next, next); 60 } 61 virtual bool is_jrt() = 0; 62 virtual bool is_jar_file() const = 0; 63 virtual const char* name() const = 0; 64 virtual JImageFile* jimage() const = 0; 65 // Constructor 66 ClassPathEntry() : _next(NULL) {} 67 // Attempt to locate file_name through this class path entry. 68 // Returns a class file parsing stream if successfull. 69 virtual ClassFileStream* open_stream(const char* name, TRAPS) = 0; 70 // Debugging 71 NOT_PRODUCT(virtual void compile_the_world(Handle loader, TRAPS) = 0;) 72 }; 73 74 class ClassPathDirEntry: public ClassPathEntry { 75 private: 76 const char* _dir; // Name of directory 77 public: 78 bool is_jrt() { return false; } 79 bool is_jar_file() const { return false; } 80 const char* name() const { return _dir; } 81 JImageFile* jimage() const { return NULL; } 82 ClassPathDirEntry(const char* dir); 83 ClassFileStream* open_stream(const char* name, TRAPS); 84 // Debugging 85 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 86 }; 87 88 89 // Type definitions for zip file and zip file entry 90 typedef void* jzfile; 91 typedef struct { 92 char *name; /* entry name */ 93 jlong time; /* modification time */ 94 jlong size; /* size of uncompressed data */ 95 jlong csize; /* size of compressed data (zero if uncompressed) */ 96 jint crc; /* crc of uncompressed data */ 97 char *comment; /* optional zip file comment */ 98 jbyte *extra; /* optional extra data */ 99 jlong pos; /* position of LOC header (if negative) or data */ 100 } jzentry; 101 102 103 class ClassPathZipEntry: public ClassPathEntry { 104 enum { 105 _unknown = 0, 106 _yes = 1, 107 _no = 2 108 }; 109 private: 110 jzfile* _zip; // The zip archive 111 const char* _zip_name; // Name of zip archive 112 bool _is_boot_append; // entry coming from -Xbootclasspath/a 113 u1 _multi_versioned; // indicates if the jar file has multi-versioned entries. 114 // It can have value of "_unknown", "_yes", or "_no" 115 public: 116 bool is_jrt() { return false; } 117 bool is_jar_file() const { return true; } 118 const char* name() const { return _zip_name; } 119 JImageFile* jimage() const { return NULL; } 120 ClassPathZipEntry(jzfile* zip, const char* zip_name, bool is_boot_append); 121 ~ClassPathZipEntry(); 122 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS); 123 u1* open_versioned_entry(const char* name, jint* filesize, TRAPS) NOT_CDS_RETURN_(NULL); 124 ClassFileStream* open_stream(const char* name, TRAPS); 125 void contents_do(void f(const char* name, void* context), void* context); 126 bool is_multiple_versioned(TRAPS) NOT_CDS_RETURN_(false); 127 // Debugging 128 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 129 }; 130 131 132 // For java image files 133 class ClassPathImageEntry: public ClassPathEntry { 134 private: 135 JImageFile* _jimage; 136 const char* _name; 137 public: 138 bool is_jrt(); 139 bool is_jar_file() const { return false; } 140 bool is_open() const { return _jimage != NULL; } 141 const char* name() const { return _name == NULL ? "" : _name; } 142 JImageFile* jimage() const { return _jimage; } 143 ClassPathImageEntry(JImageFile* jimage, const char* name); 144 ~ClassPathImageEntry(); 145 ClassFileStream* open_stream(const char* name, TRAPS); 146 147 // Debugging 148 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 149 }; 150 151 // ModuleClassPathList contains a linked list of ClassPathEntry's 152 // that have been specified for a specific module. Currently, 153 // the only way to specify a module/path pair is via the -Xpatch 154 // command line option. 155 class ModuleClassPathList : public CHeapObj<mtClass> { 156 private: 157 Symbol* _module_name; 158 // First and last entries of class path entries for a specific module 159 ClassPathEntry* _module_first_entry; 160 ClassPathEntry* _module_last_entry; 161 public: 162 Symbol* module_name() const { return _module_name; } 163 ClassPathEntry* module_first_entry() const { return _module_first_entry; } 164 ModuleClassPathList(Symbol* module_name); 165 ~ModuleClassPathList(); 166 void add_to_list(ClassPathEntry* new_entry); 167 }; 168 169 class SharedPathsMiscInfo; 170 171 class ClassLoader: AllStatic { 172 public: 173 enum ClassLoaderType { 174 BOOT_LOADER = 1, /* boot loader */ 175 PLATFORM_LOADER = 2, /* PlatformClassLoader */ 176 APP_LOADER = 3 /* AppClassLoader */ 177 }; 178 protected: 179 180 // Performance counters 181 static PerfCounter* _perf_accumulated_time; 182 static PerfCounter* _perf_classes_inited; 183 static PerfCounter* _perf_class_init_time; 184 static PerfCounter* _perf_class_init_selftime; 185 static PerfCounter* _perf_classes_verified; 186 static PerfCounter* _perf_class_verify_time; 187 static PerfCounter* _perf_class_verify_selftime; 188 static PerfCounter* _perf_classes_linked; 189 static PerfCounter* _perf_class_link_time; 190 static PerfCounter* _perf_class_link_selftime; 191 static PerfCounter* _perf_class_parse_time; 192 static PerfCounter* _perf_class_parse_selftime; 193 static PerfCounter* _perf_sys_class_lookup_time; 194 static PerfCounter* _perf_shared_classload_time; 195 static PerfCounter* _perf_sys_classload_time; 196 static PerfCounter* _perf_app_classload_time; 197 static PerfCounter* _perf_app_classload_selftime; 198 static PerfCounter* _perf_app_classload_count; 199 static PerfCounter* _perf_define_appclasses; 200 static PerfCounter* _perf_define_appclass_time; 201 static PerfCounter* _perf_define_appclass_selftime; 202 static PerfCounter* _perf_app_classfile_bytes_read; 203 static PerfCounter* _perf_sys_classfile_bytes_read; 204 205 static PerfCounter* _sync_systemLoaderLockContentionRate; 206 static PerfCounter* _sync_nonSystemLoaderLockContentionRate; 207 static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter; 208 static PerfCounter* _sync_JVMDefineClassLockFreeCounter; 209 static PerfCounter* _sync_JNIDefineClassLockFreeCounter; 210 211 static PerfCounter* _unsafe_defineClassCallCounter; 212 static PerfCounter* _isUnsyncloadClass; 213 static PerfCounter* _load_instance_class_failCounter; 214 215 // The boot class path consists of 3 ordered pieces: 216 // 1. the module/path pairs specified to -Xpatch 217 // -Xpatch:<module>=<file>(<pathsep><file>)* 218 // 2. the base piece 219 // [exploded build | jimage] 220 // 3. boot loader append path 221 // [-Xbootclasspath/a]; [jvmti appended entries] 222 // 223 // The boot loader must obey this order when attempting 224 // to load a class. 225 226 // Contains the module/path pairs specified to -Xpatch 227 static GrowableArray<ModuleClassPathList*>* _xpatch_entries; 228 229 // Contains the ClassPathEntry instances that include 230 // both the base piece and the boot loader append path. 231 static ClassPathEntry* _first_entry; 232 // Last entry in linked list of ClassPathEntry instances 233 static ClassPathEntry* _last_entry; 234 static int _num_entries; 235 236 // Marks the start of: 237 // - the boot loader's append path 238 // [-Xbootclasspath/a]; [jvmti appended entries] 239 // within the linked list of ClassPathEntry instances. 240 static ClassPathEntry* _first_append_entry; 241 242 static const char* _shared_archive; 243 244 // True if the boot path has a "modules" jimage 245 static bool _has_jimage; 246 247 // Array of module names associated with the boot class loader 248 CDS_ONLY(static GrowableArray<char*>* _boot_modules_array;) 249 250 // Array of module names associated with the platform class loader 251 CDS_ONLY(static GrowableArray<char*>* _platform_modules_array;) 252 253 // Info used by CDS 254 CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;) 255 256 // Initialization 257 static void setup_bootstrap_search_path(); 258 static void setup_search_path(const char *class_path, bool setting_bootstrap); 259 260 static void load_zip_library(); 261 static void load_jimage_library(); 262 static ClassPathEntry* create_class_path_entry(const char *path, const struct stat* st, 263 bool throw_exception, 264 bool is_boot_append, TRAPS); 265 266 public: 267 268 // If the package for the fully qualified class name is in the boot 269 // loader's package entry table then add_package() sets the classpath_index 270 // field so that get_system_package() will know to return a non-null value 271 // for the package's location. And, so that the package will be added to 272 // the list of packages returned by get_system_packages(). 273 // For packages whose classes are loaded from the boot loader class path, the 274 // classpath_index indicates which entry on the boot loader class path. 275 static bool add_package(const char *fullq_class_name, s2 classpath_index, TRAPS); 276 277 // Canonicalizes path names, so strcmp will work properly. This is mainly 278 // to avoid confusing the zip library 279 static bool get_canonical_path(const char* orig, char* out, int len); 280 static const char* file_name_for_class_name(const char* class_name, 281 int class_name_len); 282 283 public: 284 static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg); 285 static int crc32(int crc, const char* buf, int len); 286 static bool update_class_path_entry_list(const char *path, 287 bool check_for_duplicates, 288 bool mark_append_entry, 289 bool prepend_entry, 290 bool is_boot_append, 291 bool throw_exception=true); 292 static void print_bootclasspath(); 293 294 // Timing 295 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; } 296 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; } 297 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; } 298 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; } 299 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; } 300 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; } 301 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; } 302 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; } 303 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; } 304 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; } 305 static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; } 306 static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; } 307 static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; } 308 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; } 309 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; } 310 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; } 311 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; } 312 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; } 313 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; } 314 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; } 315 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; } 316 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; } 317 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; } 318 319 // Record how often system loader lock object is contended 320 static PerfCounter* sync_systemLoaderLockContentionRate() { 321 return _sync_systemLoaderLockContentionRate; 322 } 323 324 // Record how often non system loader lock object is contended 325 static PerfCounter* sync_nonSystemLoaderLockContentionRate() { 326 return _sync_nonSystemLoaderLockContentionRate; 327 } 328 329 // Record how many calls to JVM_FindLoadedClass w/o holding a lock 330 static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() { 331 return _sync_JVMFindLoadedClassLockFreeCounter; 332 } 333 334 // Record how many calls to JVM_DefineClass w/o holding a lock 335 static PerfCounter* sync_JVMDefineClassLockFreeCounter() { 336 return _sync_JVMDefineClassLockFreeCounter; 337 } 338 339 // Record how many calls to jni_DefineClass w/o holding a lock 340 static PerfCounter* sync_JNIDefineClassLockFreeCounter() { 341 return _sync_JNIDefineClassLockFreeCounter; 342 } 343 344 // Record how many calls to Unsafe_DefineClass 345 static PerfCounter* unsafe_defineClassCallCounter() { 346 return _unsafe_defineClassCallCounter; 347 } 348 349 // Record how many times SystemDictionary::load_instance_class call 350 // fails with linkageError when Unsyncloadclass flag is set. 351 static PerfCounter* load_instance_class_failCounter() { 352 return _load_instance_class_failCounter; 353 } 354 355 // Set up the module/path pairs as specified to -Xpatch 356 static void setup_xpatch_entries(); 357 358 // Sets _has_jimage to TRUE if "modules" jimage file exists 359 static void set_has_jimage(); 360 static bool has_jimage() { return _has_jimage; } 361 362 // Create the ModuleEntry for java.base 363 static void create_javabase(); 364 365 // Load individual .class file 366 static instanceKlassHandle load_class(Symbol* class_name, bool search_append_only, TRAPS); 367 368 // If the specified package has been loaded by the system, then returns 369 // the name of the directory or ZIP file that the package was loaded from. 370 // Returns null if the package was not loaded. 371 // Note: The specified name can either be the name of a class or package. 372 // If a package name is specified, then it must be "/"-separator and also 373 // end with a trailing "/". 374 static oop get_system_package(const char* name, TRAPS); 375 376 // Returns an array of Java strings representing all of the currently 377 // loaded system packages. 378 // Note: The package names returned are "/"-separated and end with a 379 // trailing "/". 380 static objArrayOop get_system_packages(TRAPS); 381 382 // Initialization 383 static void initialize(); 384 CDS_ONLY(static void initialize_shared_path();) 385 386 static int compute_Object_vtable(); 387 388 static ClassPathEntry* classpath_entry(int n) { 389 ClassPathEntry* e = ClassLoader::_first_entry; 390 while (--n >= 0) { 391 assert(e != NULL, "Not that many classpath entries."); 392 e = e->next(); 393 } 394 return e; 395 } 396 397 #if INCLUDE_CDS 398 // Sharing dump and restore 399 400 static void check_shared_classpath(const char *path); 401 static void finalize_shared_paths_misc_info(); 402 static int get_shared_paths_misc_info_size(); 403 static void* get_shared_paths_misc_info(); 404 static bool check_shared_paths_misc_info(void* info, int size); 405 static void exit_with_path_failure(const char* error, const char* message); 406 407 static s2 module_to_classloader(const char* module_name); 408 static void initialize_module_loader_map(JImageFile* jimage); 409 static s2 classloader_type(Symbol* class_name, ClassPathEntry* e, 410 int classpath_index, TRAPS); 411 #endif 412 413 static void trace_class_path(const char* msg, const char* name = NULL); 414 415 // VM monitoring and management support 416 static jlong classloader_time_ms(); 417 static jlong class_method_total_size(); 418 static jlong class_init_count(); 419 static jlong class_init_time_ms(); 420 static jlong class_verify_time_ms(); 421 static jlong class_link_count(); 422 static jlong class_link_time_ms(); 423 424 static void set_first_append_entry(ClassPathEntry* entry); 425 426 // indicates if class path already contains a entry (exact match by name) 427 static bool contains_entry(ClassPathEntry* entry); 428 429 // adds a class path list 430 static void add_to_list(ClassPathEntry* new_entry); 431 432 // prepends a class path list 433 static void prepend_to_list(ClassPathEntry* new_entry); 434 435 // creates a class path zip entry (returns NULL if JAR file cannot be opened) 436 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath, bool is_boot_append); 437 438 // add a path to class path list 439 static void add_to_list(const char* apath); 440 441 // prepend a path to class path list 442 static void prepend_to_list(const char* apath); 443 444 static bool string_ends_with(const char* str, const char* str_to_find); 445 446 // obtain package name from a fully qualified class name 447 // *bad_class_name is set to true if there's a problem with parsing class_name, to 448 // distinguish from a class_name with no package name, as both cases have a NULL return value 449 static const char* package_from_name(const char* const class_name, bool* bad_class_name = NULL); 450 451 static bool is_jrt(const char* name) { return string_ends_with(name, MODULES_IMAGE_NAME); } 452 453 // Debugging 454 static void verify() PRODUCT_RETURN; 455 456 // Force compilation of all methods in all classes in bootstrap class path (stress test) 457 #ifndef PRODUCT 458 protected: 459 static int _compile_the_world_class_counter; 460 static int _compile_the_world_method_counter; 461 public: 462 static void compile_the_world(); 463 static void compile_the_world_in(char* name, Handle loader, TRAPS); 464 static int compile_the_world_counter() { return _compile_the_world_class_counter; } 465 #endif //PRODUCT 466 }; 467 468 // PerfClassTraceTime is used to measure time for class loading related events. 469 // This class tracks cumulative time and exclusive time for specific event types. 470 // During the execution of one event, other event types (e.g. class loading and 471 // resolution) as well as recursive calls of the same event type could happen. 472 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive) 473 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime 474 // instances have been created as multiple events are happening. 475 class PerfClassTraceTime { 476 public: 477 enum { 478 CLASS_LOAD = 0, 479 PARSE_CLASS = 1, 480 CLASS_LINK = 2, 481 CLASS_VERIFY = 3, 482 CLASS_CLINIT = 4, 483 DEFINE_CLASS = 5, 484 EVENT_TYPE_COUNT = 6 485 }; 486 protected: 487 // _t tracks time from initialization to destruction of this timer instance 488 // including time for all other event types, and recursive calls of this type. 489 // When a timer is called recursively, the elapsedTimer _t would not be used. 490 elapsedTimer _t; 491 PerfLongCounter* _timep; 492 PerfLongCounter* _selftimep; 493 PerfLongCounter* _eventp; 494 // pointer to thread-local recursion counter and timer array 495 // The thread_local timers track cumulative time for specific event types 496 // exclusive of time for other event types, but including recursive calls 497 // of the same type. 498 int* _recursion_counters; 499 elapsedTimer* _timers; 500 int _event_type; 501 int _prev_active_event; 502 503 public: 504 505 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ 506 PerfLongCounter* selftimep, /* counter incremented with exclusive time */ 507 PerfLongCounter* eventp, /* event counter */ 508 int* recursion_counters, /* thread-local recursion counter array */ 509 elapsedTimer* timers, /* thread-local timer array */ 510 int type /* event type */ ) : 511 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) { 512 initialize(); 513 } 514 515 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ 516 elapsedTimer* timers, /* thread-local timer array */ 517 int type /* event type */ ) : 518 _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) { 519 initialize(); 520 } 521 522 inline void suspend() { _t.stop(); _timers[_event_type].stop(); } 523 inline void resume() { _t.start(); _timers[_event_type].start(); } 524 525 ~PerfClassTraceTime(); 526 void initialize(); 527 }; 528 529 #endif // SHARE_VM_CLASSFILE_CLASSLOADER_HPP