1 /* 2 * Copyright (c) 1997, 2017, 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/jimage.hpp" 29 #include "runtime/orderAccess.hpp" 30 #include "runtime/perfData.hpp" 31 #include "utilities/exceptions.hpp" 32 #include "utilities/macros.hpp" 33 34 // The VM class loader. 35 #include <sys/stat.h> 36 37 // Name of boot "modules" image 38 #define MODULES_IMAGE_NAME "modules" 39 40 // Class path entry (directory or zip file) 41 42 class JImageFile; 43 class ClassFileStream; 44 class PackageEntry; 45 46 class ClassPathEntry : public CHeapObj<mtClass> { 47 private: 48 ClassPathEntry* volatile _next; 49 public: 50 // Next entry in class path 51 ClassPathEntry* next() const { 52 return (ClassPathEntry*) OrderAccess::load_ptr_acquire(&_next); 53 } 54 virtual ~ClassPathEntry() {} 55 void set_next(ClassPathEntry* next) { 56 // may have unlocked readers, so ensure visibility. 57 OrderAccess::release_store_ptr(&_next, next); 58 } 59 virtual bool is_jrt() = 0; 60 virtual bool is_jar_file() const = 0; 61 virtual const char* name() const = 0; 62 virtual JImageFile* jimage() const = 0; 63 // Constructor 64 ClassPathEntry() : _next(NULL) {} 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 }; 71 72 class ClassPathDirEntry: public ClassPathEntry { 73 private: 74 const char* _dir; // Name of directory 75 public: 76 bool is_jrt() { return false; } 77 bool is_jar_file() const { return false; } 78 const char* name() const { return _dir; } 79 JImageFile* jimage() const { return NULL; } 80 ClassPathDirEntry(const char* dir); 81 virtual ~ClassPathDirEntry() {} 82 ClassFileStream* open_stream(const char* name, TRAPS); 83 // Debugging 84 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 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 class ClassPathZipEntry: public ClassPathEntry { 102 enum { 103 _unknown = 0, 104 _yes = 1, 105 _no = 2 106 }; 107 private: 108 jzfile* _zip; // The zip archive 109 const char* _zip_name; // Name of zip archive 110 bool _is_boot_append; // entry coming from -Xbootclasspath/a 111 u1 _multi_versioned; // indicates if the jar file has multi-versioned entries. 112 // It can have value of "_unknown", "_yes", or "_no" 113 public: 114 bool is_jrt() { return false; } 115 bool is_jar_file() const { return true; } 116 const char* name() const { return _zip_name; } 117 JImageFile* jimage() const { return NULL; } 118 ClassPathZipEntry(jzfile* zip, const char* zip_name, bool is_boot_append); 119 virtual ~ClassPathZipEntry(); 120 u1* open_entry(const char* name, jint* filesize, bool nul_terminate, TRAPS); 121 u1* open_versioned_entry(const char* name, jint* filesize, TRAPS) NOT_CDS_RETURN_(NULL); 122 ClassFileStream* open_stream(const char* name, TRAPS); 123 void contents_do(void f(const char* name, void* context), void* context); 124 bool is_multiple_versioned(TRAPS) NOT_CDS_RETURN_(false); 125 // Debugging 126 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 127 }; 128 129 130 // For java image files 131 class ClassPathImageEntry: public ClassPathEntry { 132 private: 133 JImageFile* _jimage; 134 const char* _name; 135 public: 136 bool is_jrt(); 137 bool is_jar_file() const { return false; } 138 bool is_open() const { return _jimage != NULL; } 139 const char* name() const { return _name == NULL ? "" : _name; } 140 JImageFile* jimage() const { return _jimage; } 141 ClassPathImageEntry(JImageFile* jimage, const char* name); 142 virtual ~ClassPathImageEntry(); 143 ClassFileStream* open_stream(const char* name, TRAPS); 144 145 // Debugging 146 NOT_PRODUCT(void compile_the_world(Handle loader, TRAPS);) 147 }; 148 149 // ModuleClassPathList contains a linked list of ClassPathEntry's 150 // that have been specified for a specific module. Currently, 151 // the only way to specify a module/path pair is via the --patch-module 152 // command line option. 153 class ModuleClassPathList : public CHeapObj<mtClass> { 154 private: 155 Symbol* _module_name; 156 // First and last entries of class path entries for a specific module 157 ClassPathEntry* _module_first_entry; 158 ClassPathEntry* _module_last_entry; 159 public: 160 Symbol* module_name() const { return _module_name; } 161 ClassPathEntry* module_first_entry() const { return _module_first_entry; } 162 ModuleClassPathList(Symbol* module_name); 163 ~ModuleClassPathList(); 164 void add_to_list(ClassPathEntry* new_entry); 165 }; 166 167 class SharedPathsMiscInfo; 168 169 class ClassLoader: AllStatic { 170 public: 171 enum ClassLoaderType { 172 BOOT_LOADER = 1, /* boot loader */ 173 PLATFORM_LOADER = 2, /* PlatformClassLoader */ 174 APP_LOADER = 3 /* AppClassLoader */ 175 }; 176 protected: 177 178 // Performance counters 179 static PerfCounter* _perf_accumulated_time; 180 static PerfCounter* _perf_classes_inited; 181 static PerfCounter* _perf_class_init_time; 182 static PerfCounter* _perf_class_init_selftime; 183 static PerfCounter* _perf_classes_verified; 184 static PerfCounter* _perf_class_verify_time; 185 static PerfCounter* _perf_class_verify_selftime; 186 static PerfCounter* _perf_classes_linked; 187 static PerfCounter* _perf_class_link_time; 188 static PerfCounter* _perf_class_link_selftime; 189 static PerfCounter* _perf_class_parse_time; 190 static PerfCounter* _perf_class_parse_selftime; 191 static PerfCounter* _perf_sys_class_lookup_time; 192 static PerfCounter* _perf_shared_classload_time; 193 static PerfCounter* _perf_sys_classload_time; 194 static PerfCounter* _perf_app_classload_time; 195 static PerfCounter* _perf_app_classload_selftime; 196 static PerfCounter* _perf_app_classload_count; 197 static PerfCounter* _perf_define_appclasses; 198 static PerfCounter* _perf_define_appclass_time; 199 static PerfCounter* _perf_define_appclass_selftime; 200 static PerfCounter* _perf_app_classfile_bytes_read; 201 static PerfCounter* _perf_sys_classfile_bytes_read; 202 203 static PerfCounter* _sync_systemLoaderLockContentionRate; 204 static PerfCounter* _sync_nonSystemLoaderLockContentionRate; 205 static PerfCounter* _sync_JVMFindLoadedClassLockFreeCounter; 206 static PerfCounter* _sync_JVMDefineClassLockFreeCounter; 207 static PerfCounter* _sync_JNIDefineClassLockFreeCounter; 208 209 static PerfCounter* _unsafe_defineClassCallCounter; 210 static PerfCounter* _isUnsyncloadClass; 211 static PerfCounter* _load_instance_class_failCounter; 212 213 // The boot class path consists of 3 ordered pieces: 214 // 1. the module/path pairs specified to --patch-module 215 // --patch-module=<module>=<file>(<pathsep><file>)* 216 // 2. the base piece 217 // [jimage | build with exploded modules] 218 // 3. boot loader append path 219 // [-Xbootclasspath/a]; [jvmti appended entries] 220 // 221 // The boot loader must obey this order when attempting 222 // to load a class. 223 224 // 1. Contains the module/path pairs specified to --patch-module 225 static GrowableArray<ModuleClassPathList*>* _patch_mod_entries; 226 227 // 2. the base piece 228 // Contains the ClassPathEntry of the modular java runtime image. 229 // If no java runtime image is present, this indicates a 230 // build with exploded modules is being used instead. 231 static ClassPathEntry* _jrt_entry; 232 static GrowableArray<ModuleClassPathList*>* _exploded_entries; 233 enum { EXPLODED_ENTRY_SIZE = 80 }; // Initial number of exploded modules 234 235 // 3. the boot loader's append path 236 // [-Xbootclasspath/a]; [jvmti appended entries] 237 // Note: boot loader append path does not support named modules. 238 static ClassPathEntry* _first_append_entry; 239 // Last entry in linked list of appended ClassPathEntry instances 240 static ClassPathEntry* _last_append_entry; 241 242 // Note: _num_entries includes the java runtime image and all 243 // the entries on the _first_append_entry linked list. 244 static int _num_entries; 245 246 // number of entries in the boot class path including the 247 // java runtime image 248 static int _num_boot_entries; 249 250 // Array of module names associated with the boot class loader 251 CDS_ONLY(static GrowableArray<char*>* _boot_modules_array;) 252 253 // Array of module names associated with the platform class loader 254 CDS_ONLY(static GrowableArray<char*>* _platform_modules_array;) 255 256 // Info used by CDS 257 CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;) 258 259 // Initialization: 260 // - setup the boot loader's system class path 261 // - setup the boot loader's patch mod entries, if present 262 // - create the ModuleEntry for java.base 263 static void setup_bootstrap_search_path(); 264 static void setup_search_path(const char *class_path, bool setting_bootstrap); 265 static void setup_patch_mod_entries(); 266 static void create_javabase(); 267 268 static void load_zip_library(); 269 static void load_jimage_library(); 270 static ClassPathEntry* create_class_path_entry(const char *path, const struct stat* st, 271 bool throw_exception, 272 bool is_boot_append, TRAPS); 273 274 public: 275 276 // If the package for the fully qualified class name is in the boot 277 // loader's package entry table then add_package() sets the classpath_index 278 // field so that get_system_package() will know to return a non-null value 279 // for the package's location. And, so that the package will be added to 280 // the list of packages returned by get_system_packages(). 281 // For packages whose classes are loaded from the boot loader class path, the 282 // classpath_index indicates which entry on the boot loader class path. 283 static bool add_package(const char *fullq_class_name, s2 classpath_index, TRAPS); 284 285 // Canonicalizes path names, so strcmp will work properly. This is mainly 286 // to avoid confusing the zip library 287 static bool get_canonical_path(const char* orig, char* out, int len); 288 static const char* file_name_for_class_name(const char* class_name, 289 int class_name_len); 290 static PackageEntry* get_package_entry(const char* class_name, ClassLoaderData* loader_data, TRAPS); 291 292 public: 293 static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg); 294 static int crc32(int crc, const char* buf, int len); 295 static bool update_class_path_entry_list(const char *path, 296 bool check_for_duplicates, 297 bool is_boot_append, 298 bool throw_exception=true); 299 static void print_bootclasspath(); 300 301 // Timing 302 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; } 303 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; } 304 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; } 305 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; } 306 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; } 307 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; } 308 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; } 309 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; } 310 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; } 311 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; } 312 static PerfCounter* perf_class_parse_time() { return _perf_class_parse_time; } 313 static PerfCounter* perf_class_parse_selftime() { return _perf_class_parse_selftime; } 314 static PerfCounter* perf_sys_class_lookup_time() { return _perf_sys_class_lookup_time; } 315 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; } 316 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; } 317 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; } 318 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; } 319 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; } 320 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; } 321 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; } 322 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; } 323 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; } 324 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; } 325 326 // Record how often system loader lock object is contended 327 static PerfCounter* sync_systemLoaderLockContentionRate() { 328 return _sync_systemLoaderLockContentionRate; 329 } 330 331 // Record how often non system loader lock object is contended 332 static PerfCounter* sync_nonSystemLoaderLockContentionRate() { 333 return _sync_nonSystemLoaderLockContentionRate; 334 } 335 336 // Record how many calls to JVM_FindLoadedClass w/o holding a lock 337 static PerfCounter* sync_JVMFindLoadedClassLockFreeCounter() { 338 return _sync_JVMFindLoadedClassLockFreeCounter; 339 } 340 341 // Record how many calls to JVM_DefineClass w/o holding a lock 342 static PerfCounter* sync_JVMDefineClassLockFreeCounter() { 343 return _sync_JVMDefineClassLockFreeCounter; 344 } 345 346 // Record how many calls to jni_DefineClass w/o holding a lock 347 static PerfCounter* sync_JNIDefineClassLockFreeCounter() { 348 return _sync_JNIDefineClassLockFreeCounter; 349 } 350 351 // Record how many calls to Unsafe_DefineClass 352 static PerfCounter* unsafe_defineClassCallCounter() { 353 return _unsafe_defineClassCallCounter; 354 } 355 356 // Record how many times SystemDictionary::load_instance_class call 357 // fails with linkageError when Unsyncloadclass flag is set. 358 static PerfCounter* load_instance_class_failCounter() { 359 return _load_instance_class_failCounter; 360 } 361 362 // Modular java runtime image is present vs. a build with exploded modules 363 static bool has_jrt_entry() { return (_jrt_entry != NULL); } 364 static ClassPathEntry* get_jrt_entry() { return _jrt_entry; } 365 366 // Add a module's exploded directory to the boot loader's exploded module build list 367 static void add_to_exploded_build_list(Symbol* module_name, TRAPS); 368 369 // Attempt load of individual class from either the patched or exploded modules build lists 370 static ClassFileStream* search_module_entries(const GrowableArray<ModuleClassPathList*>* const module_list, 371 const char* const class_name, 372 const char* const file_name, TRAPS); 373 374 // Load individual .class file 375 static InstanceKlass* load_class(Symbol* class_name, bool search_append_only, TRAPS); 376 377 // If the specified package has been loaded by the system, then returns 378 // the name of the directory or ZIP file that the package was loaded from. 379 // Returns null if the package was not loaded. 380 // Note: The specified name can either be the name of a class or package. 381 // If a package name is specified, then it must be "/"-separator and also 382 // end with a trailing "/". 383 static oop get_system_package(const char* name, TRAPS); 384 385 // Returns an array of Java strings representing all of the currently 386 // loaded system packages. 387 // Note: The package names returned are "/"-separated and end with a 388 // trailing "/". 389 static objArrayOop get_system_packages(TRAPS); 390 391 // Initialization 392 static void initialize(); 393 static void classLoader_init2(TRAPS); 394 CDS_ONLY(static void initialize_shared_path();) 395 396 static int compute_Object_vtable(); 397 398 static ClassPathEntry* classpath_entry(int n) { 399 assert(n >= 0, "sanity"); 400 assert(!has_jrt_entry() || n < _num_entries, "sanity"); 401 if (n == 0) { 402 assert(has_jrt_entry(), "No class path entry at 0 for exploded module builds"); 403 return ClassLoader::_jrt_entry; 404 } else { 405 // The java runtime image is always the first entry 406 // in the FileMapInfo::_classpath_entry_table. Even though 407 // the _jrt_entry is not included in the _first_append_entry 408 // linked list, it must be accounted for when comparing the 409 // class path vs. the shared archive class path. 410 ClassPathEntry* e = ClassLoader::_first_append_entry; 411 while (--n >= 1) { 412 assert(e != NULL, "Not that many classpath entries."); 413 e = e->next(); 414 } 415 return e; 416 } 417 } 418 419 static int number_of_classpath_entries() { 420 return _num_entries; 421 } 422 423 static bool is_in_patch_mod_entries(Symbol* module_name); 424 425 #if INCLUDE_CDS 426 // Sharing dump and restore 427 428 static void check_shared_classpath(const char *path); 429 static void finalize_shared_paths_misc_info(); 430 static int get_shared_paths_misc_info_size(); 431 static void* get_shared_paths_misc_info(); 432 static bool check_shared_paths_misc_info(void* info, int size); 433 static void exit_with_path_failure(const char* error, const char* message); 434 435 static void record_shared_class_loader_type(InstanceKlass* ik, const ClassFileStream* stream); 436 #endif 437 static JImageLocationRef jimage_find_resource(JImageFile* jf, const char* module_name, 438 const char* file_name, jlong &size); 439 440 static void trace_class_path(const char* msg, const char* name = NULL); 441 442 // VM monitoring and management support 443 static jlong classloader_time_ms(); 444 static jlong class_method_total_size(); 445 static jlong class_init_count(); 446 static jlong class_init_time_ms(); 447 static jlong class_verify_time_ms(); 448 static jlong class_link_count(); 449 static jlong class_link_time_ms(); 450 451 static void set_first_append_entry(ClassPathEntry* entry); 452 453 // indicates if class path already contains a entry (exact match by name) 454 static bool contains_append_entry(const char* name); 455 456 // adds a class path list 457 static void add_to_list(ClassPathEntry* new_entry); 458 459 // creates a class path zip entry (returns NULL if JAR file cannot be opened) 460 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath, bool is_boot_append); 461 462 // add a path to class path list 463 static void add_to_list(const char* apath); 464 465 static bool string_ends_with(const char* str, const char* str_to_find); 466 467 // obtain package name from a fully qualified class name 468 // *bad_class_name is set to true if there's a problem with parsing class_name, to 469 // distinguish from a class_name with no package name, as both cases have a NULL return value 470 static const char* package_from_name(const char* const class_name, bool* bad_class_name = NULL); 471 472 static bool is_jrt(const char* name) { return string_ends_with(name, MODULES_IMAGE_NAME); } 473 474 // Debugging 475 static void verify() PRODUCT_RETURN; 476 477 // Force compilation of all methods in all classes in bootstrap class path (stress test) 478 #ifndef PRODUCT 479 protected: 480 static int _compile_the_world_class_counter; 481 static int _compile_the_world_method_counter; 482 public: 483 static void compile_the_world(); 484 static void compile_the_world_in(char* name, Handle loader, TRAPS); 485 static int compile_the_world_counter() { return _compile_the_world_class_counter; } 486 #endif //PRODUCT 487 }; 488 489 // PerfClassTraceTime is used to measure time for class loading related events. 490 // This class tracks cumulative time and exclusive time for specific event types. 491 // During the execution of one event, other event types (e.g. class loading and 492 // resolution) as well as recursive calls of the same event type could happen. 493 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive) 494 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime 495 // instances have been created as multiple events are happening. 496 class PerfClassTraceTime { 497 public: 498 enum { 499 CLASS_LOAD = 0, 500 PARSE_CLASS = 1, 501 CLASS_LINK = 2, 502 CLASS_VERIFY = 3, 503 CLASS_CLINIT = 4, 504 DEFINE_CLASS = 5, 505 EVENT_TYPE_COUNT = 6 506 }; 507 protected: 508 // _t tracks time from initialization to destruction of this timer instance 509 // including time for all other event types, and recursive calls of this type. 510 // When a timer is called recursively, the elapsedTimer _t would not be used. 511 elapsedTimer _t; 512 PerfLongCounter* _timep; 513 PerfLongCounter* _selftimep; 514 PerfLongCounter* _eventp; 515 // pointer to thread-local recursion counter and timer array 516 // The thread_local timers track cumulative time for specific event types 517 // exclusive of time for other event types, but including recursive calls 518 // of the same type. 519 int* _recursion_counters; 520 elapsedTimer* _timers; 521 int _event_type; 522 int _prev_active_event; 523 524 public: 525 526 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ 527 PerfLongCounter* selftimep, /* counter incremented with exclusive time */ 528 PerfLongCounter* eventp, /* event counter */ 529 int* recursion_counters, /* thread-local recursion counter array */ 530 elapsedTimer* timers, /* thread-local timer array */ 531 int type /* event type */ ) : 532 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) { 533 initialize(); 534 } 535 536 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ 537 elapsedTimer* timers, /* thread-local timer array */ 538 int type /* event type */ ) : 539 _timep(timep), _selftimep(NULL), _eventp(NULL), _recursion_counters(NULL), _timers(timers), _event_type(type) { 540 initialize(); 541 } 542 543 inline void suspend() { _t.stop(); _timers[_event_type].stop(); } 544 inline void resume() { _t.start(); _timers[_event_type].start(); } 545 546 ~PerfClassTraceTime(); 547 void initialize(); 548 }; 549 550 #endif // SHARE_VM_CLASSFILE_CLASSLOADER_HPP