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(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre_JSR292) \ 150 template(AdapterMethodHandle_klass, java_lang_invoke_AdapterMethodHandle, Pre_JSR292) \ 151 template(BoundMethodHandle_klass, java_lang_invoke_BoundMethodHandle, Pre_JSR292) \ 152 template(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Pre_JSR292) \ 153 template(MethodType_klass, java_lang_invoke_MethodType, Pre_JSR292) \ 154 template(MethodTypeForm_klass, java_lang_invoke_MethodTypeForm, Pre_JSR292) \ 155 template(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre_JSR292) \ 156 template(WrongMethodTypeException_klass, java_lang_invoke_WrongMethodTypeException, Pre_JSR292) \ 157 template(CallSite_klass, java_lang_invoke_CallSite, Pre_JSR292) \ 158 template(CountingMethodHandle_klass, java_lang_invoke_CountingMethodHandle, Opt) \ 159 template(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre_JSR292) \ 160 template(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre_JSR292) \ 161 template(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre_JSR292) \ 162 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 163 \ 164 template(StringBuffer_klass, java_lang_StringBuffer, Pre) \ 165 template(StringBuilder_klass, java_lang_StringBuilder, Pre) \ 166 \ 167 /* It's NULL in non-1.4 JDKs. */ \ 168 template(StackTraceElement_klass, java_lang_StackTraceElement, Opt) \ 169 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \ 170 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 171 template(java_nio_Buffer_klass, java_nio_Buffer, Opt) \ 172 \ 173 /* If this class isn't present, it won't be referenced. */ \ 174 template(sun_misc_AtomicLongCSImpl_klass, sun_misc_AtomicLongCSImpl, Opt) \ 175 \ 176 template(sun_jkernel_DownloadManager_klass, sun_jkernel_DownloadManager, Opt_Kernel) \ 177 \ 178 template(sun_misc_PostVMInitHook_klass, sun_misc_PostVMInitHook, Opt) \ 179 \ 180 /* Preload boxing klasses */ \ 181 template(Boolean_klass, java_lang_Boolean, Pre) \ 182 template(Character_klass, java_lang_Character, Pre) \ 183 template(Float_klass, java_lang_Float, Pre) \ 184 template(Double_klass, java_lang_Double, Pre) \ 185 template(Byte_klass, java_lang_Byte, Pre) \ 186 template(Short_klass, java_lang_Short, Pre) \ 187 template(Integer_klass, java_lang_Integer, Pre) \ 188 template(Long_klass, java_lang_Long, Pre) \ 189 /*end*/ 190 191 192 class SystemDictionary : AllStatic { 193 friend class VMStructs; 194 friend class CompactingPermGenGen; 195 friend class SystemDictionaryHandles; 196 NOT_PRODUCT(friend class instanceKlassKlass;) 197 198 public: 199 enum WKID { 200 NO_WKID = 0, 201 202 #define WK_KLASS_ENUM(name, ignore_s, ignore_o) WK_KLASS_ENUM_NAME(name), 203 WK_KLASSES_DO(WK_KLASS_ENUM) 204 #undef WK_KLASS_ENUM 205 206 WKID_LIMIT, 207 208 FIRST_WKID = NO_WKID + 1 209 }; 210 211 enum InitOption { 212 Pre, // preloaded; error if not present 213 Pre_JSR292, // preloaded if EnableInvokeDynamic 214 215 // Order is significant. Options before this point require resolve_or_fail. 216 // Options after this point will use resolve_or_null instead. 217 218 Opt, // preload tried; NULL if not present 219 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection 220 Opt_Only_JDK15, // preload tried; use only with JDK1.5+ 221 Opt_Kernel, // preload tried only #ifdef KERNEL 222 OPTION_LIMIT, 223 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 224 }; 225 226 227 // Returns a class with a given class name and class loader. Loads the 228 // class if needed. If not found a NoClassDefFoundError or a 229 // ClassNotFoundException is thrown, depending on the value on the 230 // throw_error flag. For most uses the throw_error argument should be set 231 // to true. 232 233 static klassOop resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 234 // Convenient call for null loader and protection domain. 235 static klassOop resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 236 private: 237 // handle error translation for resolve_or_null results 238 static klassOop handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS); 239 240 public: 241 242 // Returns a class with a given class name and class loader. 243 // Loads the class if needed. If not found NULL is returned. 244 static klassOop resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 245 // Version with null loader and protection domain 246 static klassOop resolve_or_null(Symbol* class_name, TRAPS); 247 248 // Resolve a superclass or superinterface. Called from ClassFileParser, 249 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 250 // "child_name" is the class whose super class or interface is being resolved. 251 static klassOop resolve_super_or_fail(Symbol* child_name, 252 Symbol* class_name, 253 Handle class_loader, 254 Handle protection_domain, 255 bool is_superclass, 256 TRAPS); 257 258 // Parse new stream. This won't update the system dictionary or 259 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 260 static klassOop parse_stream(Symbol* class_name, 261 Handle class_loader, 262 Handle protection_domain, 263 ClassFileStream* st, 264 TRAPS) { 265 KlassHandle nullHandle; 266 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD); 267 } 268 static klassOop parse_stream(Symbol* class_name, 269 Handle class_loader, 270 Handle protection_domain, 271 ClassFileStream* st, 272 KlassHandle host_klass, 273 GrowableArray<Handle>* cp_patches, 274 TRAPS); 275 276 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 277 static klassOop resolve_from_stream(Symbol* class_name, Handle class_loader, 278 Handle protection_domain, 279 ClassFileStream* st, bool verify, TRAPS); 280 281 // Lookup an already loaded class. If not found NULL is returned. 282 static klassOop find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 283 284 // Lookup an already loaded instance or array class. 285 // Do not make any queries to class loaders; consult only the cache. 286 // If not found NULL is returned. 287 static klassOop find_instance_or_array_klass(Symbol* class_name, 288 Handle class_loader, 289 Handle protection_domain, 290 TRAPS); 291 292 // If the given name is known to vmSymbols, return the well-know klass: 293 static klassOop find_well_known_klass(Symbol* class_name); 294 295 // Lookup an instance or array class that has already been loaded 296 // either into the given class loader, or else into another class 297 // loader that is constrained (via loader constraints) to produce 298 // a consistent class. Do not take protection domains into account. 299 // Do not make any queries to class loaders; consult only the cache. 300 // Return NULL if the class is not found. 301 // 302 // This function is a strict superset of find_instance_or_array_klass. 303 // This function (the unchecked version) makes a conservative prediction 304 // of the result of the checked version, assuming successful lookup. 305 // If both functions return non-null, they must return the same value. 306 // Also, the unchecked version may sometimes be non-null where the 307 // checked version is null. This can occur in several ways: 308 // 1. No query has yet been made to the class loader. 309 // 2. The class loader was queried, but chose not to delegate. 310 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 311 // 4. Loading was attempted, but there was a linkage error of some sort. 312 // In all of these cases, the loader constraints on this type are 313 // satisfied, and it is safe for classes in the given class loader 314 // to manipulate strongly-typed values of the found class, subject 315 // to local linkage and access checks. 316 static klassOop find_constrained_instance_or_array_klass(Symbol* class_name, 317 Handle class_loader, 318 TRAPS); 319 320 // Iterate over all klasses in dictionary 321 // Just the classes from defining class loaders 322 static void classes_do(void f(klassOop)); 323 // Added for initialize_itable_for_klass to handle exceptions 324 static void classes_do(void f(klassOop, TRAPS), TRAPS); 325 // All classes, and their class loaders 326 static void classes_do(void f(klassOop, oop)); 327 // All classes, and their class loaders 328 // (added for helpers that use HandleMarks and ResourceMarks) 329 static void classes_do(void f(klassOop, oop, TRAPS), TRAPS); 330 // All entries in the placeholder table and their class loaders 331 static void placeholders_do(void f(Symbol*, oop)); 332 333 // Iterate over all methods in all klasses in dictionary 334 static void methods_do(void f(methodOop)); 335 336 // Garbage collection support 337 338 // This method applies "blk->do_oop" to all the pointers to "system" 339 // classes and loaders. 340 static void always_strong_oops_do(OopClosure* blk); 341 static void always_strong_classes_do(OopClosure* blk); 342 // This method applies "blk->do_oop" to all the placeholders. 343 static void placeholders_do(OopClosure* blk); 344 345 // Unload (that is, break root links to) all unmarked classes and 346 // loaders. Returns "true" iff something was unloaded. 347 static bool do_unloading(BoolObjectClosure* is_alive); 348 349 // Applies "f->do_oop" to all root oops in the system dictionary. 350 static void oops_do(OopClosure* f); 351 352 // System loader lock 353 static oop system_loader_lock() { return _system_loader_lock_obj; } 354 355 private: 356 // Traverses preloaded oops: various system classes. These are 357 // guaranteed to be in the perm gen. 358 static void preloaded_oops_do(OopClosure* f); 359 static void lazily_loaded_oops_do(OopClosure* f); 360 361 public: 362 // Sharing support. 363 static void reorder_dictionary(); 364 static void copy_buckets(char** top, char* end); 365 static void copy_table(char** top, char* end); 366 static void reverse(); 367 static void set_shared_dictionary(HashtableBucket* t, int length, 368 int number_of_entries); 369 // Printing 370 static void print() PRODUCT_RETURN; 371 static void print_class_statistics() PRODUCT_RETURN; 372 static void print_method_statistics() PRODUCT_RETURN; 373 374 // Number of contained klasses 375 // This is both fully loaded classes and classes in the process 376 // of being loaded 377 static int number_of_classes(); 378 379 // Monotonically increasing counter which grows as classes are 380 // loaded or modifications such as hot-swapping or setting/removing 381 // of breakpoints are performed 382 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 383 // Needed by evolution and breakpoint code 384 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 385 386 // Verification 387 static void verify(); 388 389 #ifdef ASSERT 390 static bool is_internal_format(Symbol* class_name); 391 #endif 392 393 // Verify class is in dictionary 394 static void verify_obj_klass_present(Handle obj, 395 Symbol* class_name, 396 Handle class_loader); 397 398 // Initialization 399 static void initialize(TRAPS); 400 401 // Fast access to commonly used classes (preloaded) 402 static klassOop check_klass(klassOop k) { 403 assert(k != NULL, "preloaded klass not initialized"); 404 return k; 405 } 406 407 static klassOop check_klass_Pre(klassOop k) { return check_klass(k); } 408 static klassOop check_klass_Pre_JSR292(klassOop k) { return EnableInvokeDynamic ? check_klass(k) : k; } 409 static klassOop check_klass_Opt(klassOop k) { return k; } 410 static klassOop check_klass_Opt_Kernel(klassOop k) { return k; } //== Opt 411 static klassOop check_klass_Opt_Only_JDK15(klassOop k) { 412 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only"); 413 return k; 414 } 415 static klassOop check_klass_Opt_Only_JDK14NewRef(klassOop k) { 416 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only"); 417 // despite the optional loading, if you use this it must be present: 418 return check_klass(k); 419 } 420 421 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 422 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 423 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 424 int limit = (int)end_id + 1; 425 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 426 } 427 428 public: 429 #define WK_KLASS_DECLARE(name, ignore_symbol, option) \ 430 static klassOop name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } 431 WK_KLASSES_DO(WK_KLASS_DECLARE); 432 #undef WK_KLASS_DECLARE 433 434 // Local definition for direct access to the private array: 435 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 436 437 static klassOop box_klass(BasicType t) { 438 assert((uint)t < T_VOID+1, "range check"); 439 return check_klass(_box_klasses[t]); 440 } 441 static BasicType box_klass_type(klassOop k); // inverse of box_klass 442 443 // methods returning lazily loaded klasses 444 // The corresponding method to load the class must be called before calling them. 445 static klassOop abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 446 447 static void load_abstract_ownable_synchronizer_klass(TRAPS); 448 449 private: 450 // Tells whether ClassLoader.loadClassInternal is present 451 static bool has_loadClassInternal() { return _has_loadClassInternal; } 452 453 public: 454 // Tells whether ClassLoader.checkPackageAccess is present 455 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 456 457 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 458 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 459 460 // Returns default system loader 461 static oop java_system_loader(); 462 463 // Compute the default system loader 464 static void compute_java_system_loader(TRAPS); 465 466 private: 467 // Mirrors for primitive classes (created eagerly) 468 static oop check_mirror(oop m) { 469 assert(m != NULL, "mirror not initialized"); 470 return m; 471 } 472 473 public: 474 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 475 476 // Check class loader constraints 477 static bool add_loader_constraint(Symbol* name, Handle loader1, 478 Handle loader2, TRAPS); 479 static char* check_signature_loaders(Symbol* signature, Handle loader1, 480 Handle loader2, bool is_method, TRAPS); 481 482 // JSR 292 483 // find the java.lang.invoke.MethodHandles::invoke method for a given signature 484 static methodOop find_method_handle_invoke(Symbol* name, 485 Symbol* signature, 486 KlassHandle accessing_klass, 487 TRAPS); 488 // ask Java to compute a java.lang.invoke.MethodType object for a given signature 489 static Handle find_method_handle_type(Symbol* signature, 490 KlassHandle accessing_klass, 491 bool for_invokeGeneric, 492 bool& return_bcp_flag, 493 TRAPS); 494 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 495 static Handle link_method_handle_constant(KlassHandle caller, 496 int ref_kind, //e.g., JVM_REF_invokeVirtual 497 KlassHandle callee, 498 Symbol* name, 499 Symbol* signature, 500 TRAPS); 501 // ask Java to create a dynamic call site, while linking an invokedynamic op 502 static Handle make_dynamic_call_site(Handle bootstrap_method, 503 // Callee information: 504 Symbol* name, 505 methodHandle signature_invoker, 506 Handle info, 507 // Caller information: 508 methodHandle caller_method, 509 int caller_bci, 510 TRAPS); 511 512 // coordinate with Java about bootstrap methods 513 static Handle find_bootstrap_method(methodHandle caller_method, 514 int caller_bci, // N.B. must be an invokedynamic 515 int cache_index, // must be corresponding main_entry 516 Handle &argument_info_result, // static BSM arguments, if any 517 TRAPS); 518 519 // Utility for printing loader "name" as part of tracing constraints 520 static const char* loader_name(oop loader) { 521 return ((loader) == NULL ? "<bootloader>" : 522 instanceKlass::cast((loader)->klass())->name()->as_C_string() ); 523 } 524 525 // Record the error when the first attempt to resolve a reference from a constant 526 // pool entry to a class fails. 527 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error); 528 static Symbol* find_resolution_error(constantPoolHandle pool, int which); 529 530 private: 531 532 enum Constants { 533 _loader_constraint_size = 107, // number of entries in constraint table 534 _resolution_error_size = 107, // number of entries in resolution error table 535 _invoke_method_size = 139, // number of entries in invoke method table 536 _nof_buckets = 1009 // number of buckets in hash table 537 }; 538 539 540 // Static variables 541 542 // Hashtable holding loaded classes. 543 static Dictionary* _dictionary; 544 545 // Hashtable holding placeholders for classes being loaded. 546 static PlaceholderTable* _placeholders; 547 548 // Hashtable holding classes from the shared archive. 549 static Dictionary* _shared_dictionary; 550 551 // Monotonically increasing counter which grows with 552 // _number_of_classes as well as hot-swapping and breakpoint setting 553 // and removal. 554 static int _number_of_modifications; 555 556 // Lock object for system class loader 557 static oop _system_loader_lock_obj; 558 559 // Constraints on class loaders 560 static LoaderConstraintTable* _loader_constraints; 561 562 // Resolution errors 563 static ResolutionErrorTable* _resolution_errors; 564 565 // Invoke methods (JSR 292) 566 static SymbolPropertyTable* _invoke_method_table; 567 568 public: 569 // for VM_CounterDecay iteration support 570 friend class CounterDecay; 571 static klassOop try_get_next_class(); 572 573 private: 574 static void validate_protection_domain(instanceKlassHandle klass, 575 Handle class_loader, 576 Handle protection_domain, TRAPS); 577 578 friend class VM_PopulateDumpSharedSpace; 579 friend class TraversePlaceholdersClosure; 580 static Dictionary* dictionary() { return _dictionary; } 581 static Dictionary* shared_dictionary() { return _shared_dictionary; } 582 static PlaceholderTable* placeholders() { return _placeholders; } 583 static LoaderConstraintTable* constraints() { return _loader_constraints; } 584 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 585 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 586 587 // Basic loading operations 588 static klassOop resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 589 static klassOop resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 590 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 591 // Wait on SystemDictionary_lock; unlocks lockObject before 592 // waiting; relocks lockObject with correct recursion count 593 // after waiting, but before reentering SystemDictionary_lock 594 // to preserve lock order semantics. 595 static void double_lock_wait(Handle lockObject, TRAPS); 596 static void define_instance_class(instanceKlassHandle k, TRAPS); 597 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name, 598 Handle class_loader, 599 instanceKlassHandle k, TRAPS); 600 static instanceKlassHandle load_shared_class(Symbol* class_name, 601 Handle class_loader, TRAPS); 602 static instanceKlassHandle load_shared_class(instanceKlassHandle ik, 603 Handle class_loader, TRAPS); 604 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 605 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 606 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 607 static bool is_parallelCapable(Handle class_loader); 608 static bool is_parallelDefine(Handle class_loader); 609 610 static klassOop find_shared_class(Symbol* class_name); 611 612 // Setup link to hierarchy 613 static void add_to_hierarchy(instanceKlassHandle k, TRAPS); 614 615 private: 616 // We pass in the hashtable index so we can calculate it outside of 617 // the SystemDictionary_lock. 618 619 // Basic find on loaded classes 620 static klassOop find_class(int index, unsigned int hash, 621 Symbol* name, Handle loader); 622 static klassOop find_class(Symbol* class_name, Handle class_loader); 623 624 // Basic find on classes in the midst of being loaded 625 static Symbol* find_placeholder(Symbol* name, Handle loader); 626 627 // Updating entry in dictionary 628 // Add a completely loaded class 629 static void add_klass(int index, Symbol* class_name, 630 Handle class_loader, KlassHandle obj); 631 632 // Add a placeholder for a class being loaded 633 static void add_placeholder(int index, 634 Symbol* class_name, 635 Handle class_loader); 636 static void remove_placeholder(int index, 637 Symbol* class_name, 638 Handle class_loader); 639 640 // Performs cleanups after resolve_super_or_fail. This typically needs 641 // to be called on failure. 642 // Won't throw, but can block. 643 static void resolution_cleanups(Symbol* class_name, 644 Handle class_loader, 645 TRAPS); 646 647 // Initialization 648 static void initialize_preloaded_classes(TRAPS); 649 650 // Class loader constraints 651 static void check_constraints(int index, unsigned int hash, 652 instanceKlassHandle k, Handle loader, 653 bool defining, TRAPS); 654 static void update_dictionary(int d_index, unsigned int d_hash, 655 int p_index, unsigned int p_hash, 656 instanceKlassHandle k, Handle loader, TRAPS); 657 658 // Variables holding commonly used klasses (preloaded) 659 static klassOop _well_known_klasses[]; 660 661 // Lazily loaded klasses 662 static volatile klassOop _abstract_ownable_synchronizer_klass; 663 664 // table of box klasses (int_klass, etc.) 665 static klassOop _box_klasses[T_VOID+1]; 666 667 static oop _java_system_loader; 668 669 static bool _has_loadClassInternal; 670 static bool _has_checkPackageAccess; 671 }; 672 673 class SystemDictionaryHandles : AllStatic { 674 public: 675 #define WK_KLASS_HANDLE_DECLARE(name, ignore_symbol, option) \ 676 static KlassHandle name() { \ 677 SystemDictionary::name(); \ 678 klassOop* loc = &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 679 return KlassHandle(loc, true); \ 680 } 681 WK_KLASSES_DO(WK_KLASS_HANDLE_DECLARE); 682 #undef WK_KLASS_HANDLE_DECLARE 683 684 static KlassHandle box_klass(BasicType t); 685 }; 686 687 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP