1 /* 2 * Copyright (c) 1997, 2024, 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_CLASSFILE_CLASSLOADER_HPP 26 #define SHARE_CLASSFILE_CLASSLOADER_HPP 27 28 #include "jimage.hpp" 29 #include "runtime/handles.hpp" 30 #include "runtime/perfDataTypes.hpp" 31 #include "utilities/exceptions.hpp" 32 #include "utilities/macros.hpp" 33 #include "utilities/zipLibrary.hpp" 34 35 // The VM class loader. 36 #include <sys/stat.h> 37 38 // Name of boot "modules" image 39 #define MODULES_IMAGE_NAME "modules" 40 41 // Class path entry (directory or zip file) 42 43 class JImageFile; 44 class ClassFileStream; 45 class PackageEntry; 46 template <typename T> class GrowableArray; 47 48 class ClassPathEntry : public CHeapObj<mtClass> { 49 private: 50 ClassPathEntry* volatile _next; 51 protected: 52 const char* copy_path(const char*path); 53 public: 54 ClassPathEntry* next() const; 55 virtual ~ClassPathEntry() {} 56 void set_next(ClassPathEntry* next); 57 58 virtual bool is_modules_image() const { return false; } 59 virtual bool is_jar_file() const { return false; } 60 // Is this entry created from the "Class-path" attribute from a JAR Manifest? 61 virtual bool from_class_path_attr() const { return false; } 62 virtual const char* name() const = 0; 63 virtual JImageFile* jimage() const { return nullptr; } 64 virtual void close_jimage() {} 65 // Constructor 66 ClassPathEntry() : _next(nullptr) {} 67 // Attempt to locate file_name through this class path entry. 68 // Returns a class file parsing stream if successful. 69 virtual ClassFileStream* open_stream(JavaThread* current, const char* name) = 0; 70 // Open the stream for a specific class loader 71 virtual ClassFileStream* open_stream_for_loader(JavaThread* current, const char* name, ClassLoaderData* loader_data) { 72 return open_stream(current, name); 73 } 74 }; 75 76 class ClassPathDirEntry: public ClassPathEntry { 77 private: 78 const char* _dir; // Name of directory 79 public: 80 const char* name() const { return _dir; } 81 ClassPathDirEntry(const char* dir) { 82 _dir = copy_path(dir); 83 } 84 virtual ~ClassPathDirEntry(); 85 ClassFileStream* open_stream(JavaThread* current, const char* name); 86 }; 87 88 class ClassPathZipEntry: public ClassPathEntry { 89 private: 90 jzfile* _zip; // The zip archive 91 const char* _zip_name; // Name of zip archive 92 bool _from_class_path_attr; // From the "Class-path" attribute of a jar file 93 public: 94 bool is_jar_file() const { return true; } 95 bool from_class_path_attr() const { return _from_class_path_attr; } 96 const char* name() const { return _zip_name; } 97 ClassPathZipEntry(jzfile* zip, const char* zip_name, bool from_class_path_attr); 98 virtual ~ClassPathZipEntry(); 99 bool has_entry(JavaThread* current, const char* name); 100 u1* open_entry(JavaThread* current, const char* name, jint* filesize, bool nul_terminate); 101 ClassFileStream* open_stream(JavaThread* current, const char* name); 102 }; 103 104 105 // For java image files 106 class ClassPathImageEntry: public ClassPathEntry { 107 private: 108 const char* _name; 109 DEBUG_ONLY(static ClassPathImageEntry* _singleton;) 110 public: 111 bool is_modules_image() const; 112 const char* name() const { return _name == nullptr ? "" : _name; } 113 JImageFile* jimage() const; 114 JImageFile* jimage_non_null() const; 115 void close_jimage(); 116 ClassPathImageEntry(JImageFile* jimage, const char* name); 117 virtual ~ClassPathImageEntry() { ShouldNotReachHere(); } 118 ClassFileStream* open_stream(JavaThread* current, const char* name); 119 ClassFileStream* open_stream_for_loader(JavaThread* current, const char* name, ClassLoaderData* loader_data); 120 }; 121 122 // ModuleClassPathList contains a linked list of ClassPathEntry's 123 // that have been specified for a specific module. Currently, 124 // the only way to specify a module/path pair is via the --patch-module 125 // command line option. 126 class ModuleClassPathList : public CHeapObj<mtClass> { 127 private: 128 Symbol* _module_name; 129 // First and last entries of class path entries for a specific module 130 ClassPathEntry* _module_first_entry; 131 ClassPathEntry* _module_last_entry; 132 public: 133 Symbol* module_name() const { return _module_name; } 134 ClassPathEntry* module_first_entry() const { return _module_first_entry; } 135 ModuleClassPathList(Symbol* module_name); 136 ~ModuleClassPathList(); 137 void add_to_list(ClassPathEntry* new_entry); 138 }; 139 140 class ClassLoader: AllStatic { 141 public: 142 enum ClassLoaderType { 143 OTHER = 0, 144 BOOT_LOADER = 1, /* boot loader */ 145 PLATFORM_LOADER = 2, /* PlatformClassLoader */ 146 APP_LOADER = 3 /* AppClassLoader */ 147 }; 148 protected: 149 150 // Performance counters 151 static PerfCounter* _perf_accumulated_time; 152 static PerfCounter* _perf_classes_inited; 153 static PerfCounter* _perf_class_init_time; 154 static PerfCounter* _perf_class_init_selftime; 155 static PerfCounter* _perf_class_init_bytecodes_count; 156 static PerfCounter* _perf_classes_verified; 157 static PerfCounter* _perf_class_verify_time; 158 static PerfCounter* _perf_class_verify_selftime; 159 static PerfCounter* _perf_classes_linked; 160 static PerfCounter* _perf_class_link_time; 161 static PerfCounter* _perf_class_link_selftime; 162 static PerfCounter* _perf_shared_classload_time; 163 static PerfCounter* _perf_sys_classload_time; 164 static PerfCounter* _perf_app_classload_time; 165 static PerfCounter* _perf_app_classload_selftime; 166 static PerfCounter* _perf_app_classload_count; 167 static PerfCounter* _perf_define_appclasses; 168 static PerfCounter* _perf_define_appclass_time; 169 static PerfCounter* _perf_define_appclass_selftime; 170 static PerfCounter* _perf_app_classfile_bytes_read; 171 static PerfCounter* _perf_sys_classfile_bytes_read; 172 static PerfCounter* _perf_preload_total_time; 173 static PerfCounter* _perf_preload_time; 174 static PerfCounter* _perf_prelink_time; 175 static PerfCounter* _perf_preinit_time; 176 static PerfCounter* _perf_preresolve_time; 177 static PerfCounter* _perf_ik_link_methods_time; 178 static PerfCounter* _perf_method_adapters_time; 179 static PerfCounter* _perf_ik_link_methods_count; 180 static PerfCounter* _perf_method_adapters_count; 181 182 static PerfTickCounters* _perf_resolve_indy_time; 183 static PerfTickCounters* _perf_resolve_invokehandle_time; 184 static PerfTickCounters* _perf_resolve_mh_time; 185 static PerfTickCounters* _perf_resolve_mt_time; 186 187 static PerfCounter* _perf_resolve_indy_count; 188 static PerfCounter* _perf_resolve_invokehandle_count; 189 static PerfCounter* _perf_resolve_mh_count; 190 static PerfCounter* _perf_resolve_mt_count; 191 192 static PerfCounter* _unsafe_defineClassCallCounter; 193 194 // Count the time taken to hash the scondary superclass arrays. 195 static PerfCounter* _perf_secondary_hash_time; 196 197 // The boot class path consists of 3 ordered pieces: 198 // 1. the module/path pairs specified to --patch-module 199 // --patch-module=<module>=<file>(<pathsep><file>)* 200 // 2. the base piece 201 // [jimage | build with exploded modules] 202 // 3. boot loader append path 203 // [-Xbootclasspath/a]; [jvmti appended entries] 204 // 205 // The boot loader must obey this order when attempting 206 // to load a class. 207 208 // 1. Contains the module/path pairs specified to --patch-module 209 static GrowableArray<ModuleClassPathList*>* _patch_mod_entries; 210 211 // 2. the base piece 212 // Contains the ClassPathEntry of the modular java runtime image. 213 // If no java runtime image is present, this indicates a 214 // build with exploded modules is being used instead. 215 static ClassPathEntry* _jrt_entry; 216 static GrowableArray<ModuleClassPathList*>* _exploded_entries; 217 enum { EXPLODED_ENTRY_SIZE = 80 }; // Initial number of exploded modules 218 219 // 3. the boot loader's append path 220 // [-Xbootclasspath/a]; [jvmti appended entries] 221 // Note: boot loader append path does not support named modules. 222 static ClassPathEntry* volatile _first_append_entry_list; 223 static ClassPathEntry* first_append_entry() { 224 return Atomic::load_acquire(&_first_append_entry_list); 225 } 226 227 // Last entry in linked list of appended ClassPathEntry instances 228 static ClassPathEntry* volatile _last_append_entry; 229 230 // Info used by CDS 231 CDS_ONLY(static ClassPathEntry* _app_classpath_entries;) 232 CDS_ONLY(static ClassPathEntry* _last_app_classpath_entry;) 233 CDS_ONLY(static ClassPathEntry* _module_path_entries;) 234 CDS_ONLY(static ClassPathEntry* _last_module_path_entry;) 235 CDS_ONLY(static void setup_app_search_path(JavaThread* current, const char* class_path);) 236 CDS_ONLY(static void setup_module_search_path(JavaThread* current, const char* path);) 237 static bool add_to_app_classpath_entries(JavaThread* current, 238 ClassPathEntry* entry, 239 bool check_for_duplicates); 240 CDS_ONLY(static void add_to_module_path_entries(const char* path, 241 ClassPathEntry* entry);) 242 243 public: 244 CDS_ONLY(static ClassPathEntry* app_classpath_entries() {return _app_classpath_entries;}) 245 CDS_ONLY(static ClassPathEntry* module_path_entries() {return _module_path_entries;}) 246 247 static bool has_bootclasspath_append() { return first_append_entry() != nullptr; } 248 249 protected: 250 // Initialization: 251 // - setup the boot loader's system class path 252 // - setup the boot loader's patch mod entries, if present 253 // - create the ModuleEntry for java.base 254 static void setup_bootstrap_search_path(JavaThread* current); 255 static void setup_bootstrap_search_path_impl(JavaThread* current, const char *class_path); 256 static void setup_patch_mod_entries(); 257 static void create_javabase(); 258 259 static void* dll_lookup(void* lib, const char* name, const char* path); 260 static void load_java_library(); 261 static void load_jimage_library(); 262 263 public: 264 static void* zip_library_handle(); 265 static jzfile* open_zip_file(const char* canonical_path, char** error_msg, JavaThread* thread); 266 static ClassPathEntry* create_class_path_entry(JavaThread* current, 267 const char *path, const struct stat* st, 268 bool is_boot_append, 269 bool from_class_path_attr); 270 271 // Canonicalizes path names, so strcmp will work properly. This is mainly 272 // to avoid confusing the zip library 273 static char* get_canonical_path(const char* orig, Thread* thread); 274 static const char* file_name_for_class_name(const char* class_name, 275 int class_name_len); 276 static PackageEntry* get_package_entry(Symbol* pkg_name, ClassLoaderData* loader_data); 277 static int crc32(int crc, const char* buf, int len); 278 static bool update_class_path_entry_list(JavaThread* current, 279 const char *path, 280 bool check_for_duplicates, 281 bool is_boot_append, 282 bool from_class_path_attr); 283 static void print_bootclasspath(); 284 285 // Timing 286 static PerfCounter* perf_accumulated_time() { return _perf_accumulated_time; } 287 static PerfCounter* perf_classes_inited() { return _perf_classes_inited; } 288 static PerfCounter* perf_class_init_time() { return _perf_class_init_time; } 289 static PerfCounter* perf_class_init_selftime() { return _perf_class_init_selftime; } 290 static PerfCounter* perf_classes_verified() { return _perf_classes_verified; } 291 static PerfCounter* perf_class_verify_time() { return _perf_class_verify_time; } 292 static PerfCounter* perf_class_verify_selftime() { return _perf_class_verify_selftime; } 293 static PerfCounter* perf_classes_linked() { return _perf_classes_linked; } 294 static PerfCounter* perf_class_link_time() { return _perf_class_link_time; } 295 static PerfCounter* perf_class_link_selftime() { return _perf_class_link_selftime; } 296 static PerfCounter* perf_shared_classload_time() { return _perf_shared_classload_time; } 297 static PerfCounter* perf_secondary_hash_time() { 298 return _perf_secondary_hash_time; 299 } 300 static PerfCounter* perf_sys_classload_time() { return _perf_sys_classload_time; } 301 static PerfCounter* perf_app_classload_time() { return _perf_app_classload_time; } 302 static PerfCounter* perf_app_classload_selftime() { return _perf_app_classload_selftime; } 303 static PerfCounter* perf_app_classload_count() { return _perf_app_classload_count; } 304 static PerfCounter* perf_define_appclasses() { return _perf_define_appclasses; } 305 static PerfCounter* perf_define_appclass_time() { return _perf_define_appclass_time; } 306 static PerfCounter* perf_define_appclass_selftime() { return _perf_define_appclass_selftime; } 307 static PerfCounter* perf_app_classfile_bytes_read() { return _perf_app_classfile_bytes_read; } 308 static PerfCounter* perf_sys_classfile_bytes_read() { return _perf_sys_classfile_bytes_read; } 309 310 static PerfCounter* perf_preload_total_time() { return _perf_preload_total_time; } 311 static PerfCounter* perf_preload_time() { return _perf_preload_time; } 312 static PerfCounter* perf_prelink_time() { return _perf_prelink_time; } 313 static PerfCounter* perf_preinit_time() { return _perf_preinit_time; } 314 static PerfCounter* perf_preresolve_time() { return _perf_preresolve_time; } 315 static PerfCounter* perf_ik_link_methods_time() { return _perf_ik_link_methods_time; } 316 static PerfCounter* perf_method_adapters_time() { return _perf_method_adapters_time; } 317 static PerfCounter* perf_ik_link_methods_count() { return _perf_ik_link_methods_count; } 318 static PerfCounter* perf_method_adapters_count() { return _perf_method_adapters_count; } 319 320 static PerfTickCounters* perf_resolve_invokedynamic_time() { return _perf_resolve_indy_time; } 321 static PerfTickCounters* perf_resolve_invokehandle_time() { return _perf_resolve_invokehandle_time; } 322 static PerfTickCounters* perf_resolve_method_handle_time() { return _perf_resolve_mh_time; } 323 static PerfTickCounters* perf_resolve_method_type_time() { return _perf_resolve_mt_time; } 324 325 static PerfCounter* perf_resolve_invokedynamic_count() { return _perf_resolve_indy_count; } 326 static PerfCounter* perf_resolve_invokehandle_count() { return _perf_resolve_invokehandle_count; } 327 static PerfCounter* perf_resolve_method_handle_count() { return _perf_resolve_mh_count; } 328 static PerfCounter* perf_resolve_method_type_count() { return _perf_resolve_mt_count; } 329 330 static PerfCounter* perf_class_init_bytecodes_count() { return _perf_class_init_bytecodes_count; } 331 332 static void print_counters(); 333 334 // Record how many calls to Unsafe_DefineClass 335 static PerfCounter* unsafe_defineClassCallCounter() { 336 return _unsafe_defineClassCallCounter; 337 } 338 339 // Modular java runtime image is present vs. a build with exploded modules 340 static bool has_jrt_entry() { return (_jrt_entry != nullptr); } 341 static ClassPathEntry* get_jrt_entry() { return _jrt_entry; } 342 static void close_jrt_image(); 343 344 // Add a module's exploded directory to the boot loader's exploded module build list 345 static void add_to_exploded_build_list(JavaThread* current, Symbol* module_name); 346 347 // Search the module list for the class file stream based on the file name and java package 348 static ClassFileStream* search_module_entries(JavaThread* current, 349 const GrowableArray<ModuleClassPathList*>* const module_list, 350 PackageEntry* pkg_entry, // Java package entry derived from the class name 351 const char* const file_name); 352 353 // Load individual .class file 354 static InstanceKlass* load_class(Symbol* class_name, PackageEntry* pkg_entry, bool search_append_only, TRAPS); 355 356 // If the specified package has been loaded by the system, then returns 357 // the name of the directory or ZIP file that the package was loaded from. 358 // Returns null if the package was not loaded. 359 // Note: The specified name can either be the name of a class or package. 360 // If a package name is specified, then it must be "/"-separator and also 361 // end with a trailing "/". 362 static oop get_system_package(const char* name, TRAPS); 363 364 // Returns an array of Java strings representing all of the currently 365 // loaded system packages. 366 // Note: The package names returned are "/"-separated and end with a 367 // trailing "/". 368 static objArrayOop get_system_packages(TRAPS); 369 370 // Initialization 371 static void initialize(TRAPS); 372 static void classLoader_init2(JavaThread* current); 373 CDS_ONLY(static void initialize_shared_path(JavaThread* current);) 374 CDS_ONLY(static void initialize_module_path(TRAPS);) 375 376 static int compute_Object_vtable(); 377 378 static ClassPathEntry* classpath_entry(int n); 379 380 static bool is_in_patch_mod_entries(Symbol* module_name); 381 382 #if INCLUDE_CDS 383 // Sharing dump and restore 384 385 // Helper function used by CDS code to get the number of boot classpath 386 // entries during shared classpath setup time. 387 static int num_boot_classpath_entries(); 388 389 static ClassPathEntry* get_next_boot_classpath_entry(ClassPathEntry* e); 390 391 // Helper function used by CDS code to get the number of app classpath 392 // entries during shared classpath setup time. 393 static int num_app_classpath_entries(); 394 395 // Helper function used by CDS code to get the number of module path 396 // entries during shared classpath setup time. 397 static int num_module_path_entries(); 398 static void exit_with_path_failure(const char* error, const char* message); 399 static char* skip_uri_protocol(char* source); 400 static void record_result(JavaThread* current, InstanceKlass* ik, 401 const ClassFileStream* stream, bool redefined); 402 #endif 403 404 static char* lookup_vm_options(); 405 406 // Determines if the named module is present in the 407 // modules jimage file or in the exploded modules directory. 408 static bool is_module_observable(const char* module_name); 409 410 static JImageLocationRef jimage_find_resource(JImageFile* jf, const char* module_name, 411 const char* file_name, jlong &size); 412 413 static void trace_class_path(const char* msg, const char* name = nullptr); 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 static jlong class_init_bytecodes_count(); 424 425 // adds a class path to the boot append entries 426 static void add_to_boot_append_entries(ClassPathEntry* new_entry); 427 428 // creates a class path zip entry (returns null if JAR file cannot be opened) 429 static ClassPathZipEntry* create_class_path_zip_entry(const char *apath); 430 431 static bool string_ends_with(const char* str, const char* str_to_find); 432 433 // Extract package name from a fully qualified class name 434 // *bad_class_name is set to true if there's a problem with parsing class_name, to 435 // distinguish from a class_name with no package name, as both cases have a null return value 436 static Symbol* package_from_class_name(const Symbol* class_name, bool* bad_class_name = nullptr); 437 438 // Debugging 439 static void verify() PRODUCT_RETURN; 440 }; 441 442 // PerfClassTraceTime is used to measure time for class loading related events. 443 // This class tracks cumulative time and exclusive time for specific event types. 444 // During the execution of one event, other event types (e.g. class loading and 445 // resolution) as well as recursive calls of the same event type could happen. 446 // Only one elapsed timer (cumulative) and one thread-local self timer (exclusive) 447 // (i.e. only one event type) are active at a time even multiple PerfClassTraceTime 448 // instances have been created as multiple events are happening. 449 class PerfClassTraceTime { 450 public: 451 enum { 452 CLASS_LOAD = 0, 453 CLASS_LINK = 1, 454 CLASS_VERIFY = 2, 455 CLASS_CLINIT = 3, 456 DEFINE_CLASS = 4, 457 EVENT_TYPE_COUNT = 5 458 }; 459 protected: 460 // _t tracks time from initialization to destruction of this timer instance 461 // including time for all other event types, and recursive calls of this type. 462 // When a timer is called recursively, the elapsedTimer _t would not be used. 463 elapsedTimer _t; 464 PerfLongCounter* _timep; 465 PerfLongCounter* _selftimep; 466 PerfLongCounter* _eventp; 467 // pointer to thread-local recursion counter and timer array 468 // The thread_local timers track cumulative time for specific event types 469 // exclusive of time for other event types, but including recursive calls 470 // of the same type. 471 int* _recursion_counters; 472 elapsedTimer* _timers; 473 int _event_type; 474 int _prev_active_event; 475 476 public: 477 478 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ 479 PerfLongCounter* selftimep, /* counter incremented with exclusive time */ 480 PerfLongCounter* eventp, /* event counter */ 481 int* recursion_counters, /* thread-local recursion counter array */ 482 elapsedTimer* timers, /* thread-local timer array */ 483 int type /* event type */ ) : 484 _timep(timep), _selftimep(selftimep), _eventp(eventp), _recursion_counters(recursion_counters), _timers(timers), _event_type(type) { 485 initialize(); 486 } 487 488 inline PerfClassTraceTime(PerfLongCounter* timep, /* counter incremented with inclusive time */ 489 elapsedTimer* timers, /* thread-local timer array */ 490 int type /* event type */ ) : 491 _timep(timep), _selftimep(nullptr), _eventp(nullptr), _recursion_counters(nullptr), _timers(timers), _event_type(type) { 492 initialize(); 493 } 494 495 ~PerfClassTraceTime(); 496 void initialize(); 497 }; 498 499 #endif // SHARE_CLASSFILE_CLASSLOADER_HPP