1 /* 2 * Copyright (c) 1997, 2018, 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/classLoader.hpp" 29 #include "jvmci/systemDictionary_jvmci.hpp" 30 #include "oops/objArrayOop.hpp" 31 #include "oops/symbol.hpp" 32 #include "runtime/java.hpp" 33 #include "runtime/reflectionUtils.hpp" 34 #include "runtime/signature.hpp" 35 #include "utilities/hashtable.hpp" 36 37 // The dictionary in each ClassLoaderData stores all loaded classes, either 38 // initiatied by its class loader or defined by its class loader: 39 // 40 // class loader -> ClassLoaderData -> [class, protection domain set] 41 // 42 // Classes are loaded lazily. The default VM class loader is 43 // represented as NULL. 44 45 // The underlying data structure is an open hash table (Dictionary) per 46 // ClassLoaderData with a fixed number of buckets. During loading the 47 // class loader object is locked, (for the VM loader a private lock object is used). 48 // The global SystemDictionary_lock is held for all additions into the ClassLoaderData 49 // dictionaries. TODO: fix lock granularity so that class loading can 50 // be done concurrently, but only by different loaders. 51 // 52 // During loading a placeholder (name, loader) is temporarily placed in 53 // a side data structure, and is used to detect ClassCircularityErrors 54 // and to perform verification during GC. A GC can occur in the midst 55 // of class loading, as we call out to Java, have to take locks, etc. 56 // 57 // When class loading is finished, a new entry is added to the dictionary 58 // of the class loader and the placeholder is removed. Note that the protection 59 // domain field of the dictionary entry has not yet been filled in when 60 // the "real" dictionary entry is created. 61 // 62 // Clients of this class who are interested in finding if a class has 63 // been completely loaded -- not classes in the process of being loaded -- 64 // can read the dictionary unlocked. This is safe because 65 // - entries are only deleted at safepoints 66 // - readers cannot come to a safepoint while actively examining 67 // an entry (an entry cannot be deleted from under a reader) 68 // - entries must be fully formed before they are available to concurrent 69 // readers (we must ensure write ordering) 70 // 71 // Note that placeholders are deleted at any time, as they are removed 72 // when a class is completely loaded. Therefore, readers as well as writers 73 // of placeholders must hold the SystemDictionary_lock. 74 // 75 76 class ClassFileStream; 77 class Dictionary; 78 class PlaceholderTable; 79 class LoaderConstraintTable; 80 template <MEMFLAGS F> class HashtableBucket; 81 class ResolutionErrorTable; 82 class SymbolPropertyTable; 83 class ProtectionDomainCacheTable; 84 class ProtectionDomainCacheEntry; 85 class GCTimer; 86 class OopStorage; 87 88 // Certain classes are preloaded, such as java.lang.Object and java.lang.String. 89 // They are all "well-known", in the sense that no class loader is allowed 90 // to provide a different definition. 91 // 92 // These klasses must all have names defined in vmSymbols. 93 94 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 95 96 // Each well-known class has a short klass name (like object_klass), 97 // a vmSymbol name (like java_lang_Object), and a flag word 98 // that makes some minor distinctions, like whether the klass 99 // is preloaded, optional, release-specific, etc. 100 // The order of these definitions is significant; it is the order in which 101 // preloading is actually performed by resolve_preloaded_classes. 102 103 #define WK_KLASSES_DO(do_klass) \ 104 /* well-known classes */ \ 105 do_klass(Object_klass, java_lang_Object, Pre ) \ 106 do_klass(String_klass, java_lang_String, Pre ) \ 107 do_klass(Class_klass, java_lang_Class, Pre ) \ 108 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \ 109 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \ 110 do_klass(Serializable_klass, java_io_Serializable, Pre ) \ 111 do_klass(System_klass, java_lang_System, Pre ) \ 112 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \ 113 do_klass(Error_klass, java_lang_Error, Pre ) \ 114 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \ 115 do_klass(Exception_klass, java_lang_Exception, Pre ) \ 116 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \ 117 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \ 118 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \ 119 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \ 120 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \ 121 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \ 122 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \ 123 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \ 124 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \ 125 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \ 126 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \ 127 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \ 128 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \ 129 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \ 130 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \ 131 \ 132 /* Preload ref klasses and set reference types */ \ 133 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \ 134 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \ 135 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \ 136 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \ 137 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \ 138 \ 139 do_klass(Thread_klass, java_lang_Thread, Pre ) \ 140 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \ 141 do_klass(Properties_klass, java_util_Properties, Pre ) \ 142 do_klass(Module_klass, java_lang_Module, Pre ) \ 143 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \ 144 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \ 145 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \ 146 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \ 147 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \ 148 \ 149 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 150 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 151 do_klass(reflect_MagicAccessorImpl_klass, reflect_MagicAccessorImpl, Opt ) \ 152 do_klass(reflect_MethodAccessorImpl_klass, reflect_MethodAccessorImpl, Pre ) \ 153 do_klass(reflect_ConstructorAccessorImpl_klass, reflect_ConstructorAccessorImpl, Pre ) \ 154 do_klass(reflect_DelegatingClassLoader_klass, reflect_DelegatingClassLoader, Opt ) \ 155 do_klass(reflect_ConstantPool_klass, reflect_ConstantPool, Opt ) \ 156 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, reflect_UnsafeStaticFieldAccessorImpl, Opt ) \ 157 do_klass(reflect_CallerSensitive_klass, reflect_CallerSensitive, Opt ) \ 158 \ 159 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 160 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \ 161 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \ 162 do_klass(VarHandle_klass, java_lang_invoke_VarHandle, Pre ) \ 163 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \ 164 do_klass(ResolvedMethodName_klass, java_lang_invoke_ResolvedMethodName, Pre ) \ 165 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \ 166 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \ 167 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \ 168 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \ 169 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \ 170 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre ) \ 171 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \ 172 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \ 173 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \ 174 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 175 \ 176 do_klass(AssertionStatusDirectives_klass, java_lang_AssertionStatusDirectives, Pre ) \ 177 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \ 178 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \ 179 do_klass(internal_Unsafe_klass, jdk_internal_misc_Unsafe, Pre ) \ 180 do_klass(module_Modules_klass, jdk_internal_module_Modules, Pre ) \ 181 \ 182 /* support for CDS */ \ 183 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \ 184 do_klass(URL_klass, java_net_URL, Pre ) \ 185 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \ 186 do_klass(jdk_internal_loader_ClassLoaders_klass, jdk_internal_loader_ClassLoaders, Pre ) \ 187 do_klass(jdk_internal_loader_ClassLoaders_AppClassLoader_klass, jdk_internal_loader_ClassLoaders_AppClassLoader, Pre ) \ 188 do_klass(jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass, jdk_internal_loader_ClassLoaders_PlatformClassLoader, Pre ) \ 189 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \ 190 do_klass(Configuration_klass, java_lang_module_Configuration, Pre ) \ 191 do_klass(ImmutableCollections_ListN_klass, java_util_ImmutableCollections_ListN, Pre ) \ 192 do_klass(ImmutableCollections_MapN_klass, java_util_ImmutableCollections_MapN, Pre ) \ 193 do_klass(ImmutableCollections_SetN_klass, java_util_ImmutableCollections_SetN, Pre ) \ 194 do_klass(ArchivedModuleGraph_klass, jdk_internal_module_ArchivedModuleGraph, Pre ) \ 195 \ 196 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 197 \ 198 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 199 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \ 200 \ 201 /* Stack Walking */ \ 202 do_klass(StackWalker_klass, java_lang_StackWalker, Opt ) \ 203 do_klass(AbstractStackWalker_klass, java_lang_StackStreamFactory_AbstractStackWalker, Opt ) \ 204 do_klass(StackFrameInfo_klass, java_lang_StackFrameInfo, Opt ) \ 205 do_klass(LiveStackFrameInfo_klass, java_lang_LiveStackFrameInfo, Opt ) \ 206 \ 207 /* support for stack dump lock analysis */ \ 208 do_klass(java_util_concurrent_locks_AbstractOwnableSynchronizer_klass, java_util_concurrent_locks_AbstractOwnableSynchronizer, Pre ) \ 209 \ 210 /* Preload boxing klasses */ \ 211 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \ 212 do_klass(Character_klass, java_lang_Character, Pre ) \ 213 do_klass(Float_klass, java_lang_Float, Pre ) \ 214 do_klass(Double_klass, java_lang_Double, Pre ) \ 215 do_klass(Byte_klass, java_lang_Byte, Pre ) \ 216 do_klass(Short_klass, java_lang_Short, Pre ) \ 217 do_klass(Integer_klass, java_lang_Integer, Pre ) \ 218 do_klass(Integer_IntegerCache_klass, java_lang_Integer_IntegerCache, Pre ) \ 219 do_klass(Long_klass, java_lang_Long, Pre ) \ 220 \ 221 /* JVMCI classes. These are loaded on-demand. */ \ 222 JVMCI_WK_KLASSES_DO(do_klass) \ 223 \ 224 /*end*/ 225 226 227 class SystemDictionary : AllStatic { 228 friend class VMStructs; 229 friend class SystemDictionaryHandles; 230 231 public: 232 enum WKID { 233 NO_WKID = 0, 234 235 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 236 WK_KLASSES_DO(WK_KLASS_ENUM) 237 #undef WK_KLASS_ENUM 238 239 WKID_LIMIT, 240 241 #if INCLUDE_JVMCI 242 FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(JVMCI_klass), 243 LAST_JVMCI_WKID = WK_KLASS_ENUM_NAME(Value_klass), 244 #endif 245 246 FIRST_WKID = NO_WKID + 1 247 }; 248 249 enum InitOption { 250 Pre, // preloaded; error if not present 251 252 // Order is significant. Options before this point require resolve_or_fail. 253 // Options after this point will use resolve_or_null instead. 254 255 Opt, // preload tried; NULL if not present 256 #if INCLUDE_JVMCI 257 Jvmci, // preload tried; error if not present if JVMCI enabled 258 #endif 259 OPTION_LIMIT, 260 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 261 }; 262 263 264 // Returns a class with a given class name and class loader. Loads the 265 // class if needed. If not found a NoClassDefFoundError or a 266 // ClassNotFoundException is thrown, depending on the value on the 267 // throw_error flag. For most uses the throw_error argument should be set 268 // to true. 269 270 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 271 // Convenient call for null loader and protection domain. 272 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 273 protected: 274 // handle error translation for resolve_or_null results 275 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, Klass* klass, TRAPS); 276 277 public: 278 279 // Returns a class with a given class name and class loader. 280 // Loads the class if needed. If not found NULL is returned. 281 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 282 // Version with null loader and protection domain 283 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 284 285 // Resolve a superclass or superinterface. Called from ClassFileParser, 286 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 287 // "child_name" is the class whose super class or interface is being resolved. 288 static InstanceKlass* resolve_super_or_fail(Symbol* child_name, 289 Symbol* class_name, 290 Handle class_loader, 291 Handle protection_domain, 292 bool is_superclass, 293 TRAPS); 294 295 // Parse new stream. This won't update the dictionary or 296 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 297 // Also used by Unsafe_DefineAnonymousClass 298 static InstanceKlass* parse_stream(Symbol* class_name, 299 Handle class_loader, 300 Handle protection_domain, 301 ClassFileStream* st, 302 TRAPS) { 303 return parse_stream(class_name, 304 class_loader, 305 protection_domain, 306 st, 307 NULL, // host klass 308 NULL, // cp_patches 309 THREAD); 310 } 311 static InstanceKlass* parse_stream(Symbol* class_name, 312 Handle class_loader, 313 Handle protection_domain, 314 ClassFileStream* st, 315 const InstanceKlass* host_klass, 316 GrowableArray<Handle>* cp_patches, 317 TRAPS); 318 319 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 320 static InstanceKlass* resolve_from_stream(Symbol* class_name, 321 Handle class_loader, 322 Handle protection_domain, 323 ClassFileStream* st, 324 TRAPS); 325 326 // Lookup an already loaded class. If not found NULL is returned. 327 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 328 329 // Lookup an already loaded instance or array class. 330 // Do not make any queries to class loaders; consult only the cache. 331 // If not found NULL is returned. 332 static Klass* find_instance_or_array_klass(Symbol* class_name, 333 Handle class_loader, 334 Handle protection_domain, 335 TRAPS); 336 337 // Lookup an instance or array class that has already been loaded 338 // either into the given class loader, or else into another class 339 // loader that is constrained (via loader constraints) to produce 340 // a consistent class. Do not take protection domains into account. 341 // Do not make any queries to class loaders; consult only the cache. 342 // Return NULL if the class is not found. 343 // 344 // This function is a strict superset of find_instance_or_array_klass. 345 // This function (the unchecked version) makes a conservative prediction 346 // of the result of the checked version, assuming successful lookup. 347 // If both functions return non-null, they must return the same value. 348 // Also, the unchecked version may sometimes be non-null where the 349 // checked version is null. This can occur in several ways: 350 // 1. No query has yet been made to the class loader. 351 // 2. The class loader was queried, but chose not to delegate. 352 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 353 // 4. Loading was attempted, but there was a linkage error of some sort. 354 // In all of these cases, the loader constraints on this type are 355 // satisfied, and it is safe for classes in the given class loader 356 // to manipulate strongly-typed values of the found class, subject 357 // to local linkage and access checks. 358 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 359 Handle class_loader, 360 TRAPS); 361 362 static void classes_do(MetaspaceClosure* it); 363 // Iterate over all methods in all klasses 364 365 static void methods_do(void f(Method*)); 366 367 // Garbage collection support 368 369 // Unload (that is, break root links to) all unmarked classes and 370 // loaders. Returns "true" iff something was unloaded. 371 static bool do_unloading(GCTimer* gc_timer, 372 bool do_cleaning = true); 373 374 // Used by DumpSharedSpaces only to remove classes that failed verification 375 static void remove_classes_in_error_state(); 376 377 static int calculate_systemdictionary_size(int loadedclasses); 378 379 // Applies "f->do_oop" to all root oops in the system dictionary. 380 static void oops_do(OopClosure* f); 381 382 // System loader lock 383 static oop system_loader_lock() { return _system_loader_lock_obj; } 384 385 public: 386 // Sharing support. 387 static void reorder_dictionary_for_sharing() NOT_CDS_RETURN; 388 static void combine_shared_dictionaries(); 389 static size_t count_bytes_for_buckets(); 390 static size_t count_bytes_for_table(); 391 static void copy_buckets(char* top, char* end); 392 static void copy_table(char* top, char* end); 393 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 394 int number_of_entries); 395 // Printing 396 static void print() { return print_on(tty); } 397 static void print_on(outputStream* st); 398 static void print_shared(outputStream* st); 399 static void dump(outputStream* st, bool verbose); 400 401 // Monotonically increasing counter which grows as classes are 402 // loaded or modifications such as hot-swapping or setting/removing 403 // of breakpoints are performed 404 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 405 // Needed by evolution and breakpoint code 406 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 407 408 // Verification 409 static void verify(); 410 411 // Initialization 412 static void initialize(TRAPS); 413 414 // Checked fast access to commonly used classes - mostly preloaded 415 static InstanceKlass* check_klass(InstanceKlass* k) { 416 assert(k != NULL, "klass not loaded"); 417 return k; 418 } 419 420 static InstanceKlass* check_klass_Pre(InstanceKlass* k) { return check_klass(k); } 421 static InstanceKlass* check_klass_Opt(InstanceKlass* k) { return k; } 422 423 JVMCI_ONLY(static InstanceKlass* check_klass_Jvmci(InstanceKlass* k) { return k; }) 424 425 static bool resolve_wk_klass(WKID id, int init_opt, TRAPS); 426 static void resolve_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 427 static void resolve_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 428 int limit = (int)end_id + 1; 429 resolve_wk_klasses_until((WKID) limit, start_id, THREAD); 430 } 431 432 public: 433 #define WK_KLASS_DECLARE(name, symbol, option) \ 434 static InstanceKlass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 435 static InstanceKlass** name##_addr() { \ 436 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 437 } 438 WK_KLASSES_DO(WK_KLASS_DECLARE); 439 #undef WK_KLASS_DECLARE 440 441 static InstanceKlass* well_known_klass(WKID id) { 442 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 443 return _well_known_klasses[id]; 444 } 445 446 static InstanceKlass** well_known_klass_addr(WKID id) { 447 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 448 return &_well_known_klasses[id]; 449 } 450 static void well_known_klasses_do(MetaspaceClosure* it); 451 452 // Local definition for direct access to the private array: 453 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 454 455 static InstanceKlass* box_klass(BasicType t) { 456 assert((uint)t < T_VOID+1, "range check"); 457 return check_klass(_box_klasses[t]); 458 } 459 static BasicType box_klass_type(Klass* k); // inverse of box_klass 460 461 protected: 462 // Returns the class loader data to be used when looking up/updating the 463 // system dictionary. 464 static ClassLoaderData *class_loader_data(Handle class_loader) { 465 return ClassLoaderData::class_loader_data(class_loader()); 466 } 467 468 public: 469 // Tells whether ClassLoader.checkPackageAccess is present 470 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 471 472 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 473 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 474 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 475 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 476 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 477 478 // Returns java system loader 479 static oop java_system_loader(); 480 481 // Returns java platform loader 482 static oop java_platform_loader(); 483 484 // Compute the java system and platform loaders 485 static void compute_java_loaders(TRAPS); 486 487 // Register a new class loader 488 static ClassLoaderData* register_loader(Handle class_loader); 489 protected: 490 // Mirrors for primitive classes (created eagerly) 491 static oop check_mirror(oop m) { 492 assert(m != NULL, "mirror not initialized"); 493 return m; 494 } 495 496 public: 497 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 498 499 // Check class loader constraints 500 static bool add_loader_constraint(Symbol* name, Handle loader1, 501 Handle loader2, TRAPS); 502 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 503 Handle loader2, bool is_method, TRAPS); 504 505 // JSR 292 506 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 507 // (asks Java to compute it if necessary, except in a compiler thread) 508 static methodHandle find_method_handle_invoker(Klass* klass, 509 Symbol* name, 510 Symbol* signature, 511 Klass* accessing_klass, 512 Handle *appendix_result, 513 Handle *method_type_result, 514 TRAPS); 515 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 516 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 517 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 518 Symbol* signature, 519 TRAPS); 520 521 // compute java_mirror (java.lang.Class instance) for a type ("I", "[[B", "LFoo;", etc.) 522 // Either the accessing_klass or the CL/PD can be non-null, but not both. 523 static Handle find_java_mirror_for_type(Symbol* signature, 524 Klass* accessing_klass, 525 Handle class_loader, 526 Handle protection_domain, 527 SignatureStream::FailureMode failure_mode, 528 TRAPS); 529 static Handle find_java_mirror_for_type(Symbol* signature, 530 Klass* accessing_klass, 531 SignatureStream::FailureMode failure_mode, 532 TRAPS) { 533 // callee will fill in CL/PD from AK, if they are needed 534 return find_java_mirror_for_type(signature, accessing_klass, Handle(), Handle(), 535 failure_mode, THREAD); 536 } 537 538 539 // fast short-cut for the one-character case: 540 static oop find_java_mirror_for_type(char signature_char); 541 542 // find a java.lang.invoke.MethodType object for a given signature 543 // (asks Java to compute it if necessary, except in a compiler thread) 544 static Handle find_method_handle_type(Symbol* signature, 545 Klass* accessing_klass, 546 TRAPS); 547 548 // find a java.lang.Class object for a given signature 549 static Handle find_field_handle_type(Symbol* signature, 550 Klass* accessing_klass, 551 TRAPS); 552 553 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 554 static Handle link_method_handle_constant(Klass* caller, 555 int ref_kind, //e.g., JVM_REF_invokeVirtual 556 Klass* callee, 557 Symbol* name, 558 Symbol* signature, 559 TRAPS); 560 561 // ask Java to compute a constant by invoking a BSM given a Dynamic_info CP entry 562 static Handle link_dynamic_constant(Klass* caller, 563 int condy_index, 564 Handle bootstrap_specifier, 565 Symbol* name, 566 Symbol* type, 567 TRAPS); 568 569 // ask Java to create a dynamic call site, while linking an invokedynamic op 570 static methodHandle find_dynamic_call_site_invoker(Klass* caller, 571 int indy_index, 572 Handle bootstrap_method, 573 Symbol* name, 574 Symbol* type, 575 Handle *appendix_result, 576 Handle *method_type_result, 577 TRAPS); 578 579 // Record the error when the first attempt to resolve a reference from a constant 580 // pool entry to a class fails. 581 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error, 582 Symbol* message); 583 static void delete_resolution_error(ConstantPool* pool); 584 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which, 585 Symbol** message); 586 587 588 static ProtectionDomainCacheEntry* cache_get(Handle protection_domain); 589 590 protected: 591 592 enum Constants { 593 _loader_constraint_size = 107, // number of entries in constraint table 594 _resolution_error_size = 107, // number of entries in resolution error table 595 _invoke_method_size = 139, // number of entries in invoke method table 596 _shared_dictionary_size = 1009, // number of entries in shared dictionary 597 _placeholder_table_size = 1009 // number of entries in hash table for placeholders 598 }; 599 600 601 // Static tables owned by the SystemDictionary 602 603 // Hashtable holding placeholders for classes being loaded. 604 static PlaceholderTable* _placeholders; 605 606 // Hashtable holding classes from the shared archive. 607 static Dictionary* _shared_dictionary; 608 609 // Monotonically increasing counter which grows with 610 // loading classes as well as hot-swapping and breakpoint setting 611 // and removal. 612 static int _number_of_modifications; 613 614 // Lock object for system class loader 615 static oop _system_loader_lock_obj; 616 617 // Constraints on class loaders 618 static LoaderConstraintTable* _loader_constraints; 619 620 // Resolution errors 621 static ResolutionErrorTable* _resolution_errors; 622 623 // Invoke methods (JSR 292) 624 static SymbolPropertyTable* _invoke_method_table; 625 626 // ProtectionDomain cache 627 static ProtectionDomainCacheTable* _pd_cache_table; 628 629 // VM weak OopStorage object. 630 static OopStorage* _vm_weak_oop_storage; 631 632 protected: 633 static void validate_protection_domain(InstanceKlass* klass, 634 Handle class_loader, 635 Handle protection_domain, TRAPS); 636 637 friend class VM_PopulateDumpSharedSpace; 638 friend class TraversePlaceholdersClosure; 639 static Dictionary* shared_dictionary() { return _shared_dictionary; } 640 static PlaceholderTable* placeholders() { return _placeholders; } 641 static LoaderConstraintTable* constraints() { return _loader_constraints; } 642 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 643 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 644 645 // Basic loading operations 646 static InstanceKlass* resolve_instance_class_or_null_helper(Symbol* name, 647 Handle class_loader, 648 Handle protection_domain, 649 TRAPS); 650 static InstanceKlass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 651 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 652 static InstanceKlass* handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 653 // Wait on SystemDictionary_lock; unlocks lockObject before 654 // waiting; relocks lockObject with correct recursion count 655 // after waiting, but before reentering SystemDictionary_lock 656 // to preserve lock order semantics. 657 static void double_lock_wait(Handle lockObject, TRAPS); 658 static void define_instance_class(InstanceKlass* k, TRAPS); 659 static InstanceKlass* find_or_define_instance_class(Symbol* class_name, 660 Handle class_loader, 661 InstanceKlass* k, TRAPS); 662 static bool is_shared_class_visible(Symbol* class_name, InstanceKlass* ik, 663 Handle class_loader, TRAPS); 664 static InstanceKlass* load_shared_class(InstanceKlass* ik, 665 Handle class_loader, 666 Handle protection_domain, 667 TRAPS); 668 static InstanceKlass* load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 669 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 670 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 671 static bool is_parallelCapable(Handle class_loader); 672 static bool is_parallelDefine(Handle class_loader); 673 674 public: 675 static InstanceKlass* load_shared_class(Symbol* class_name, 676 Handle class_loader, 677 TRAPS); 678 static bool is_system_class_loader(oop class_loader); 679 static bool is_platform_class_loader(oop class_loader); 680 static void clear_invoke_method_table(); 681 682 // Returns TRUE if the method is a non-public member of class java.lang.Object. 683 static bool is_nonpublic_Object_method(Method* m) { 684 assert(m != NULL, "Unexpected NULL Method*"); 685 return !m->is_public() && m->method_holder() == SystemDictionary::Object_klass(); 686 } 687 688 static void initialize_oop_storage(); 689 static OopStorage* vm_weak_oop_storage(); 690 691 protected: 692 static InstanceKlass* find_shared_class(Symbol* class_name); 693 694 // Setup link to hierarchy 695 static void add_to_hierarchy(InstanceKlass* k, TRAPS); 696 697 // Basic find on loaded classes 698 static InstanceKlass* find_class(unsigned int hash, 699 Symbol* name, Dictionary* dictionary); 700 static InstanceKlass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 701 702 // Basic find on classes in the midst of being loaded 703 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 704 705 // Add a placeholder for a class being loaded 706 static void add_placeholder(int index, 707 Symbol* class_name, 708 ClassLoaderData* loader_data); 709 static void remove_placeholder(int index, 710 Symbol* class_name, 711 ClassLoaderData* loader_data); 712 713 // Performs cleanups after resolve_super_or_fail. This typically needs 714 // to be called on failure. 715 // Won't throw, but can block. 716 static void resolution_cleanups(Symbol* class_name, 717 ClassLoaderData* loader_data, 718 TRAPS); 719 720 // Resolve preloaded classes so they can be used like SystemDictionary::String_klass() 721 static void resolve_preloaded_classes(TRAPS); 722 723 // Class loader constraints 724 static void check_constraints(unsigned int hash, 725 InstanceKlass* k, Handle loader, 726 bool defining, TRAPS); 727 static void update_dictionary(unsigned int d_hash, 728 int p_index, unsigned int p_hash, 729 InstanceKlass* k, Handle loader, 730 TRAPS); 731 732 // Variables holding commonly used klasses (preloaded) 733 static InstanceKlass* _well_known_klasses[]; 734 735 // table of box klasses (int_klass, etc.) 736 static InstanceKlass* _box_klasses[T_VOID+1]; 737 738 private: 739 static oop _java_system_loader; 740 static oop _java_platform_loader; 741 742 static bool _has_checkPackageAccess; 743 }; 744 745 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP