1 /* 2 * Copyright (c) 1997, 2011, 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_SYSTEMDICTIONARY_HPP 26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP 27 28 #include "classfile/classFileStream.hpp" 29 #include "classfile/classLoader.hpp" 30 #include "oops/objArrayOop.hpp" 31 #include "oops/symbol.hpp" 32 #include "runtime/java.hpp" 33 #include "runtime/reflectionUtils.hpp" 34 #include "utilities/hashtable.hpp" 35 36 // The system dictionary stores all loaded classes and maps: 37 // 38 // [class name,class loader] -> class i.e. [Symbol*,oop] -> klassOop 39 // 40 // Classes are loaded lazily. The default VM class loader is 41 // represented as NULL. 42 43 // The underlying data structure is an open hash table with a fixed number 44 // of buckets. During loading the loader object is locked, (for the VM loader 45 // a private lock object is used). Class loading can thus be done concurrently, 46 // but only by different loaders. 47 // 48 // During loading a placeholder (name, loader) is temporarily placed in 49 // a side data structure, and is used to detect ClassCircularityErrors 50 // and to perform verification during GC. A GC can occur in the midst 51 // of class loading, as we call out to Java, have to take locks, etc. 52 // 53 // When class loading is finished, a new entry is added to the system 54 // dictionary and the place holder is removed. Note that the protection 55 // domain field of the system dictionary has not yet been filled in when 56 // the "real" system dictionary entry is created. 57 // 58 // Clients of this class who are interested in finding if a class has 59 // been completely loaded -- not classes in the process of being loaded -- 60 // can read the SystemDictionary unlocked. This is safe because 61 // - entries are only deleted at safepoints 62 // - readers cannot come to a safepoint while actively examining 63 // an entry (an entry cannot be deleted from under a reader) 64 // - entries must be fully formed before they are available to concurrent 65 // readers (we must ensure write ordering) 66 // 67 // Note that placeholders are deleted at any time, as they are removed 68 // when a class is completely loaded. Therefore, readers as well as writers 69 // of placeholders must hold the SystemDictionary_lock. 70 // 71 72 class Dictionary; 73 class PlaceholderTable; 74 class LoaderConstraintTable; 75 class HashtableBucket; 76 class ResolutionErrorTable; 77 class SymbolPropertyTable; 78 79 // Certain classes are preloaded, such as java.lang.Object and java.lang.String. 80 // They are all "well-known", in the sense that no class loader is allowed 81 // to provide a different definition. 82 // 83 // These klasses must all have names defined in vmSymbols. 84 85 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 86 87 // Each well-known class has a short klass name (like object_klass), 88 // a vmSymbol name (like java_lang_Object), and a flag word 89 // that makes some minor distinctions, like whether the klass 90 // is preloaded, optional, release-specific, etc. 91 // The order of these definitions is significant; it is the order in which 92 // preloading is actually performed by initialize_preloaded_classes. 93 94 #define WK_KLASSES_DO(template) \ 95 /* well-known classes */ \ 96 template(Object_klass, java_lang_Object, Pre) \ 97 template(String_klass, java_lang_String, Pre) \ 98 template(Class_klass, java_lang_Class, Pre) \ 99 template(Cloneable_klass, java_lang_Cloneable, Pre) \ 100 template(ClassLoader_klass, java_lang_ClassLoader, Pre) \ 101 template(Serializable_klass, java_io_Serializable, Pre) \ 102 template(System_klass, java_lang_System, Pre) \ 103 template(Throwable_klass, java_lang_Throwable, Pre) \ 104 template(Error_klass, java_lang_Error, Pre) \ 105 template(ThreadDeath_klass, java_lang_ThreadDeath, Pre) \ 106 template(Exception_klass, java_lang_Exception, Pre) \ 107 template(RuntimeException_klass, java_lang_RuntimeException, Pre) \ 108 template(ProtectionDomain_klass, java_security_ProtectionDomain, Pre) \ 109 template(AccessControlContext_klass, java_security_AccessControlContext, Pre) \ 110 template(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre) \ 111 template(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre) \ 112 template(LinkageError_klass, java_lang_LinkageError, Pre) \ 113 template(ClassCastException_klass, java_lang_ClassCastException, Pre) \ 114 template(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre) \ 115 template(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre) \ 116 template(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre) \ 117 template(StackOverflowError_klass, java_lang_StackOverflowError, Pre) \ 118 template(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre) \ 119 template(Reference_klass, java_lang_ref_Reference, Pre) \ 120 \ 121 /* Preload ref klasses and set reference types */ \ 122 template(SoftReference_klass, java_lang_ref_SoftReference, Pre) \ 123 template(WeakReference_klass, java_lang_ref_WeakReference, Pre) \ 124 template(FinalReference_klass, java_lang_ref_FinalReference, Pre) \ 125 template(PhantomReference_klass, java_lang_ref_PhantomReference, Pre) \ 126 template(Finalizer_klass, java_lang_ref_Finalizer, Pre) \ 127 \ 128 template(Thread_klass, java_lang_Thread, Pre) \ 129 template(ThreadGroup_klass, java_lang_ThreadGroup, Pre) \ 130 template(Properties_klass, java_util_Properties, Pre) \ 131 template(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre) \ 132 template(reflect_Field_klass, java_lang_reflect_Field, Pre) \ 133 template(reflect_Method_klass, java_lang_reflect_Method, Pre) \ 134 template(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre) \ 135 \ 136 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 137 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \ 138 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 139 template(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt) \ 140 template(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Opt_Only_JDK14NewRef) \ 141 template(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Opt_Only_JDK14NewRef) \ 142 template(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt) \ 143 template(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt_Only_JDK15) \ 144 template(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15) \ 145 \ 146 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 147 template(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre_JSR292) \ 148 template(MemberName_klass, java_lang_invoke_MemberName, Pre_JSR292) \ 149 template(MethodHandleImpl_klass, sun_dyn_MethodHandleImpl, Opt) /* AllowTransitionalJSR292 ONLY */ \ 150 template(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre_JSR292) \ 151 template(AdapterMethodHandle_klass, java_lang_invoke_AdapterMethodHandle, Pre_JSR292) \ 152 template(BoundMethodHandle_klass, java_lang_invoke_BoundMethodHandle, Pre_JSR292) \ 153 template(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Pre_JSR292) \ 154 template(MethodType_klass, java_lang_invoke_MethodType, Pre_JSR292) \ 155 template(MethodTypeForm_klass, java_lang_invoke_MethodTypeForm, Pre_JSR292) \ 156 template(WrongMethodTypeException_klass, java_lang_invoke_WrongMethodTypeException, Pre_JSR292) \ 157 template(Linkage_klass, java_lang_invoke_Linkage, Opt) /* AllowTransitionalJSR292 ONLY */ \ 158 template(CallSite_klass, java_lang_invoke_CallSite, Pre_JSR292) \ 159 /* Note: MethodHandle must be first, and CallSite last in group */ \ 160 \ 161 template(StringBuffer_klass, java_lang_StringBuffer, Pre) \ 162 template(StringBuilder_klass, java_lang_StringBuilder, Pre) \ 163 \ 164 /* It's NULL in non-1.4 JDKs. */ \ 165 template(StackTraceElement_klass, java_lang_StackTraceElement, Opt) \ 166 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \ 167 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 168 template(java_nio_Buffer_klass, java_nio_Buffer, Opt) \ 169 \ 170 /* If this class isn't present, it won't be referenced. */ \ 171 template(sun_misc_AtomicLongCSImpl_klass, sun_misc_AtomicLongCSImpl, Opt) \ 172 \ 173 template(sun_jkernel_DownloadManager_klass, sun_jkernel_DownloadManager, Opt_Kernel) \ 174 \ 175 template(sun_misc_PostVMInitHook_klass, sun_misc_PostVMInitHook, Opt) \ 176 \ 177 /* Preload boxing klasses */ \ 178 template(Boolean_klass, java_lang_Boolean, Pre) \ 179 template(Character_klass, java_lang_Character, Pre) \ 180 template(Float_klass, java_lang_Float, Pre) \ 181 template(Double_klass, java_lang_Double, Pre) \ 182 template(Byte_klass, java_lang_Byte, Pre) \ 183 template(Short_klass, java_lang_Short, Pre) \ 184 template(Integer_klass, java_lang_Integer, Pre) \ 185 template(Long_klass, java_lang_Long, Pre) \ 186 /*end*/ 187 188 189 class SystemDictionary : AllStatic { 190 friend class VMStructs; 191 friend class CompactingPermGenGen; 192 friend class SystemDictionaryHandles; 193 NOT_PRODUCT(friend class instanceKlassKlass;) 194 195 public: 196 enum WKID { 197 NO_WKID = 0, 198 199 #define WK_KLASS_ENUM(name, ignore_s, ignore_o) WK_KLASS_ENUM_NAME(name), 200 WK_KLASSES_DO(WK_KLASS_ENUM) 201 #undef WK_KLASS_ENUM 202 203 WKID_LIMIT, 204 205 FIRST_WKID = NO_WKID + 1 206 }; 207 208 enum InitOption { 209 Pre, // preloaded; error if not present 210 Pre_JSR292, // preloaded if EnableInvokeDynamic 211 212 // Order is significant. Options before this point require resolve_or_fail. 213 // Options after this point will use resolve_or_null instead. 214 215 Opt, // preload tried; NULL if not present 216 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection 217 Opt_Only_JDK15, // preload tried; use only with JDK1.5+ 218 Opt_Kernel, // preload tried only #ifdef KERNEL 219 OPTION_LIMIT, 220 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 221 }; 222 223 224 // Returns a class with a given class name and class loader. Loads the 225 // class if needed. If not found a NoClassDefFoundError or a 226 // ClassNotFoundException is thrown, depending on the value on the 227 // throw_error flag. For most uses the throw_error argument should be set 228 // to true. 229 230 static klassOop resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 231 // Convenient call for null loader and protection domain. 232 static klassOop resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 233 private: 234 // handle error translation for resolve_or_null results 235 static klassOop handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS); 236 237 public: 238 239 // Returns a class with a given class name and class loader. 240 // Loads the class if needed. If not found NULL is returned. 241 static klassOop resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 242 // Version with null loader and protection domain 243 static klassOop resolve_or_null(Symbol* class_name, TRAPS); 244 245 // Resolve a superclass or superinterface. Called from ClassFileParser, 246 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 247 // "child_name" is the class whose super class or interface is being resolved. 248 static klassOop resolve_super_or_fail(Symbol* child_name, 249 Symbol* class_name, 250 Handle class_loader, 251 Handle protection_domain, 252 bool is_superclass, 253 TRAPS); 254 255 // Parse new stream. This won't update the system dictionary or 256 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 257 static klassOop parse_stream(Symbol* class_name, 258 Handle class_loader, 259 Handle protection_domain, 260 ClassFileStream* st, 261 TRAPS) { 262 KlassHandle nullHandle; 263 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD); 264 } 265 static klassOop parse_stream(Symbol* class_name, 266 Handle class_loader, 267 Handle protection_domain, 268 ClassFileStream* st, 269 KlassHandle host_klass, 270 GrowableArray<Handle>* cp_patches, 271 TRAPS); 272 273 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 274 static klassOop resolve_from_stream(Symbol* class_name, Handle class_loader, 275 Handle protection_domain, 276 ClassFileStream* st, bool verify, TRAPS); 277 278 // Lookup an already loaded class. If not found NULL is returned. 279 static klassOop find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 280 281 // Lookup an already loaded instance or array class. 282 // Do not make any queries to class loaders; consult only the cache. 283 // If not found NULL is returned. 284 static klassOop find_instance_or_array_klass(Symbol* class_name, 285 Handle class_loader, 286 Handle protection_domain, 287 TRAPS); 288 289 // If the given name is known to vmSymbols, return the well-know klass: 290 static klassOop find_well_known_klass(Symbol* class_name); 291 292 // Lookup an instance or array class that has already been loaded 293 // either into the given class loader, or else into another class 294 // loader that is constrained (via loader constraints) to produce 295 // a consistent class. Do not take protection domains into account. 296 // Do not make any queries to class loaders; consult only the cache. 297 // Return NULL if the class is not found. 298 // 299 // This function is a strict superset of find_instance_or_array_klass. 300 // This function (the unchecked version) makes a conservative prediction 301 // of the result of the checked version, assuming successful lookup. 302 // If both functions return non-null, they must return the same value. 303 // Also, the unchecked version may sometimes be non-null where the 304 // checked version is null. This can occur in several ways: 305 // 1. No query has yet been made to the class loader. 306 // 2. The class loader was queried, but chose not to delegate. 307 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 308 // 4. Loading was attempted, but there was a linkage error of some sort. 309 // In all of these cases, the loader constraints on this type are 310 // satisfied, and it is safe for classes in the given class loader 311 // to manipulate strongly-typed values of the found class, subject 312 // to local linkage and access checks. 313 static klassOop find_constrained_instance_or_array_klass(Symbol* class_name, 314 Handle class_loader, 315 TRAPS); 316 317 // Iterate over all klasses in dictionary 318 // Just the classes from defining class loaders 319 static void classes_do(void f(klassOop)); 320 // Added for initialize_itable_for_klass to handle exceptions 321 static void classes_do(void f(klassOop, TRAPS), TRAPS); 322 // All classes, and their class loaders 323 static void classes_do(void f(klassOop, oop)); 324 // All classes, and their class loaders 325 // (added for helpers that use HandleMarks and ResourceMarks) 326 static void classes_do(void f(klassOop, oop, TRAPS), TRAPS); 327 // All entries in the placeholder table and their class loaders 328 static void placeholders_do(void f(Symbol*, oop)); 329 330 // Iterate over all methods in all klasses in dictionary 331 static void methods_do(void f(methodOop)); 332 333 // Garbage collection support 334 335 // This method applies "blk->do_oop" to all the pointers to "system" 336 // classes and loaders. 337 static void always_strong_oops_do(OopClosure* blk); 338 static void always_strong_classes_do(OopClosure* blk); 339 // This method applies "blk->do_oop" to all the placeholders. 340 static void placeholders_do(OopClosure* blk); 341 342 // Unload (that is, break root links to) all unmarked classes and 343 // loaders. Returns "true" iff something was unloaded. 344 static bool do_unloading(BoolObjectClosure* is_alive); 345 346 // Applies "f->do_oop" to all root oops in the system dictionary. 347 static void oops_do(OopClosure* f); 348 349 // System loader lock 350 static oop system_loader_lock() { return _system_loader_lock_obj; } 351 352 private: 353 // Traverses preloaded oops: various system classes. These are 354 // guaranteed to be in the perm gen. 355 static void preloaded_oops_do(OopClosure* f); 356 static void lazily_loaded_oops_do(OopClosure* f); 357 358 public: 359 // Sharing support. 360 static void reorder_dictionary(); 361 static void copy_buckets(char** top, char* end); 362 static void copy_table(char** top, char* end); 363 static void reverse(); 364 static void set_shared_dictionary(HashtableBucket* t, int length, 365 int number_of_entries); 366 // Printing 367 static void print() PRODUCT_RETURN; 368 static void print_class_statistics() PRODUCT_RETURN; 369 static void print_method_statistics() PRODUCT_RETURN; 370 371 // Number of contained klasses 372 // This is both fully loaded classes and classes in the process 373 // of being loaded 374 static int number_of_classes(); 375 376 // Monotonically increasing counter which grows as classes are 377 // loaded or modifications such as hot-swapping or setting/removing 378 // of breakpoints are performed 379 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 380 // Needed by evolution and breakpoint code 381 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 382 383 // Verification 384 static void verify(); 385 386 #ifdef ASSERT 387 static bool is_internal_format(Symbol* class_name); 388 #endif 389 390 // Verify class is in dictionary 391 static void verify_obj_klass_present(Handle obj, 392 Symbol* class_name, 393 Handle class_loader); 394 395 // Initialization 396 static void initialize(TRAPS); 397 398 // Fast access to commonly used classes (preloaded) 399 static klassOop check_klass(klassOop k) { 400 assert(k != NULL, "preloaded klass not initialized"); 401 return k; 402 } 403 404 static klassOop check_klass_Pre(klassOop k) { return check_klass(k); } 405 static klassOop check_klass_Pre_JSR292(klassOop k) { return EnableInvokeDynamic ? check_klass(k) : k; } 406 static klassOop check_klass_Opt(klassOop k) { return k; } 407 static klassOop check_klass_Opt_Kernel(klassOop k) { return k; } //== Opt 408 static klassOop check_klass_Opt_Only_JDK15(klassOop k) { 409 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only"); 410 return k; 411 } 412 static klassOop check_klass_Opt_Only_JDK14NewRef(klassOop k) { 413 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only"); 414 // despite the optional loading, if you use this it must be present: 415 return check_klass(k); 416 } 417 418 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 419 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 420 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 421 int limit = (int)end_id + 1; 422 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 423 } 424 425 static Symbol* find_backup_symbol(Symbol* symbol, const char* from_prefix, const char* to_prefix); 426 427 public: 428 #define WK_KLASS_DECLARE(name, ignore_symbol, option) \ 429 static klassOop name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } 430 WK_KLASSES_DO(WK_KLASS_DECLARE); 431 #undef WK_KLASS_DECLARE 432 433 // Local definition for direct access to the private array: 434 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 435 436 static klassOop box_klass(BasicType t) { 437 assert((uint)t < T_VOID+1, "range check"); 438 return check_klass(_box_klasses[t]); 439 } 440 static BasicType box_klass_type(klassOop k); // inverse of box_klass 441 442 // methods returning lazily loaded klasses 443 // The corresponding method to load the class must be called before calling them. 444 static klassOop abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 445 446 static void load_abstract_ownable_synchronizer_klass(TRAPS); 447 448 static Symbol* find_backup_class_name(Symbol* class_name_symbol); 449 static Symbol* find_backup_signature(Symbol* signature_symbol); 450 451 private: 452 // Tells whether ClassLoader.loadClassInternal is present 453 static bool has_loadClassInternal() { return _has_loadClassInternal; } 454 455 public: 456 // Tells whether ClassLoader.checkPackageAccess is present 457 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 458 459 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 460 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 461 462 // Returns default system loader 463 static oop java_system_loader(); 464 465 // Compute the default system loader 466 static void compute_java_system_loader(TRAPS); 467 468 private: 469 // Mirrors for primitive classes (created eagerly) 470 static oop check_mirror(oop m) { 471 assert(m != NULL, "mirror not initialized"); 472 return m; 473 } 474 475 public: 476 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 477 478 // Check class loader constraints 479 static bool add_loader_constraint(Symbol* name, Handle loader1, 480 Handle loader2, TRAPS); 481 static char* check_signature_loaders(Symbol* signature, Handle loader1, 482 Handle loader2, bool is_method, TRAPS); 483 484 // JSR 292 485 // find the java.lang.invoke.MethodHandles::invoke method for a given signature 486 static methodOop find_method_handle_invoke(Symbol* name, 487 Symbol* signature, 488 KlassHandle accessing_klass, 489 TRAPS); 490 // ask Java to compute a java.lang.invoke.MethodType object for a given signature 491 static Handle find_method_handle_type(Symbol* signature, 492 KlassHandle accessing_klass, 493 bool for_invokeGeneric, 494 bool& return_bcp_flag, 495 TRAPS); 496 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 497 static Handle link_method_handle_constant(KlassHandle caller, 498 int ref_kind, //e.g., JVM_REF_invokeVirtual 499 KlassHandle callee, 500 Symbol* name, 501 Symbol* signature, 502 TRAPS); 503 // ask Java to create a dynamic call site, while linking an invokedynamic op 504 static Handle make_dynamic_call_site(Handle bootstrap_method, 505 // Callee information: 506 Symbol* name, 507 methodHandle signature_invoker, 508 Handle info, 509 // Caller information: 510 methodHandle caller_method, 511 int caller_bci, 512 TRAPS); 513 514 // coordinate with Java about bootstrap methods 515 static Handle find_bootstrap_method(methodHandle caller_method, 516 int caller_bci, // N.B. must be an invokedynamic 517 int cache_index, // must be corresponding main_entry 518 Handle &argument_info_result, // static BSM arguments, if any 519 TRAPS); 520 521 // Utility for printing loader "name" as part of tracing constraints 522 static const char* loader_name(oop loader) { 523 return ((loader) == NULL ? "<bootloader>" : 524 instanceKlass::cast((loader)->klass())->name()->as_C_string() ); 525 } 526 527 // Record the error when the first attempt to resolve a reference from a constant 528 // pool entry to a class fails. 529 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error); 530 static Symbol* find_resolution_error(constantPoolHandle pool, int which); 531 532 private: 533 534 enum Constants { 535 _loader_constraint_size = 107, // number of entries in constraint table 536 _resolution_error_size = 107, // number of entries in resolution error table 537 _invoke_method_size = 139, // number of entries in invoke method table 538 _nof_buckets = 1009 // number of buckets in hash table 539 }; 540 541 542 // Static variables 543 544 // Hashtable holding loaded classes. 545 static Dictionary* _dictionary; 546 547 // Hashtable holding placeholders for classes being loaded. 548 static PlaceholderTable* _placeholders; 549 550 // Hashtable holding classes from the shared archive. 551 static Dictionary* _shared_dictionary; 552 553 // Monotonically increasing counter which grows with 554 // _number_of_classes as well as hot-swapping and breakpoint setting 555 // and removal. 556 static int _number_of_modifications; 557 558 // Lock object for system class loader 559 static oop _system_loader_lock_obj; 560 561 // Constraints on class loaders 562 static LoaderConstraintTable* _loader_constraints; 563 564 // Resolution errors 565 static ResolutionErrorTable* _resolution_errors; 566 567 // Invoke methods (JSR 292) 568 static SymbolPropertyTable* _invoke_method_table; 569 570 public: 571 // for VM_CounterDecay iteration support 572 friend class CounterDecay; 573 static klassOop try_get_next_class(); 574 575 private: 576 static void validate_protection_domain(instanceKlassHandle klass, 577 Handle class_loader, 578 Handle protection_domain, TRAPS); 579 580 friend class VM_PopulateDumpSharedSpace; 581 friend class TraversePlaceholdersClosure; 582 static Dictionary* dictionary() { return _dictionary; } 583 static Dictionary* shared_dictionary() { return _shared_dictionary; } 584 static PlaceholderTable* placeholders() { return _placeholders; } 585 static LoaderConstraintTable* constraints() { return _loader_constraints; } 586 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 587 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 588 589 // Basic loading operations 590 static klassOop resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 591 static klassOop resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 592 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 593 // Wait on SystemDictionary_lock; unlocks lockObject before 594 // waiting; relocks lockObject with correct recursion count 595 // after waiting, but before reentering SystemDictionary_lock 596 // to preserve lock order semantics. 597 static void double_lock_wait(Handle lockObject, TRAPS); 598 static void define_instance_class(instanceKlassHandle k, TRAPS); 599 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name, 600 Handle class_loader, 601 instanceKlassHandle k, TRAPS); 602 static instanceKlassHandle load_shared_class(Symbol* class_name, 603 Handle class_loader, TRAPS); 604 static instanceKlassHandle load_shared_class(instanceKlassHandle ik, 605 Handle class_loader, TRAPS); 606 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 607 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 608 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 609 static bool is_parallelCapable(Handle class_loader); 610 static bool is_parallelDefine(Handle class_loader); 611 612 static klassOop find_shared_class(Symbol* class_name); 613 614 // Setup link to hierarchy 615 static void add_to_hierarchy(instanceKlassHandle k, TRAPS); 616 617 private: 618 // We pass in the hashtable index so we can calculate it outside of 619 // the SystemDictionary_lock. 620 621 // Basic find on loaded classes 622 static klassOop find_class(int index, unsigned int hash, 623 Symbol* name, Handle loader); 624 static klassOop find_class(Symbol* class_name, Handle class_loader); 625 626 // Basic find on classes in the midst of being loaded 627 static Symbol* find_placeholder(Symbol* name, Handle loader); 628 629 // Updating entry in dictionary 630 // Add a completely loaded class 631 static void add_klass(int index, Symbol* class_name, 632 Handle class_loader, KlassHandle obj); 633 634 // Add a placeholder for a class being loaded 635 static void add_placeholder(int index, 636 Symbol* class_name, 637 Handle class_loader); 638 static void remove_placeholder(int index, 639 Symbol* class_name, 640 Handle class_loader); 641 642 // Performs cleanups after resolve_super_or_fail. This typically needs 643 // to be called on failure. 644 // Won't throw, but can block. 645 static void resolution_cleanups(Symbol* class_name, 646 Handle class_loader, 647 TRAPS); 648 649 // Initialization 650 static void initialize_preloaded_classes(TRAPS); 651 652 // Class loader constraints 653 static void check_constraints(int index, unsigned int hash, 654 instanceKlassHandle k, Handle loader, 655 bool defining, TRAPS); 656 static void update_dictionary(int d_index, unsigned int d_hash, 657 int p_index, unsigned int p_hash, 658 instanceKlassHandle k, Handle loader, TRAPS); 659 660 // Variables holding commonly used klasses (preloaded) 661 static klassOop _well_known_klasses[]; 662 663 // Lazily loaded klasses 664 static volatile klassOop _abstract_ownable_synchronizer_klass; 665 666 // table of box klasses (int_klass, etc.) 667 static klassOop _box_klasses[T_VOID+1]; 668 669 static oop _java_system_loader; 670 671 static bool _has_loadClassInternal; 672 static bool _has_checkPackageAccess; 673 }; 674 675 class SystemDictionaryHandles : AllStatic { 676 public: 677 #define WK_KLASS_HANDLE_DECLARE(name, ignore_symbol, option) \ 678 static KlassHandle name() { \ 679 SystemDictionary::name(); \ 680 klassOop* loc = &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 681 return KlassHandle(loc, true); \ 682 } 683 WK_KLASSES_DO(WK_KLASS_HANDLE_DECLARE); 684 #undef WK_KLASS_HANDLE_DECLARE 685 686 static KlassHandle box_klass(BasicType t); 687 }; 688 689 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP