1 /* 2 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_CLASSFILE_SYSTEMDICTIONARY_HPP 26 #define SHARE_CLASSFILE_SYSTEMDICTIONARY_HPP 27 28 #include "classfile/classLoader.hpp" 29 #include "oops/objArrayOop.hpp" 30 #include "oops/symbol.hpp" 31 #include "runtime/java.hpp" 32 #include "runtime/reflectionUtils.hpp" 33 #include "runtime/signature.hpp" 34 #include "utilities/hashtable.hpp" 35 36 // The dictionary in each ClassLoaderData stores all loaded classes, either 37 // initiatied by its class loader or defined by its class loader: 38 // 39 // class loader -> ClassLoaderData -> [class, protection domain set] 40 // 41 // Classes are loaded lazily. The default VM class loader is 42 // represented as NULL. 43 44 // The underlying data structure is an open hash table (Dictionary) per 45 // ClassLoaderData with a fixed number of buckets. During loading the 46 // class loader object is locked, (for the VM loader a private lock object is used). 47 // The global SystemDictionary_lock is held for all additions into the ClassLoaderData 48 // dictionaries. TODO: fix lock granularity so that class loading can 49 // be done concurrently, but only by different loaders. 50 // 51 // During loading a placeholder (name, loader) is temporarily placed in 52 // a side data structure, and is used to detect ClassCircularityErrors 53 // and to perform verification during GC. A GC can occur in the midst 54 // of class loading, as we call out to Java, have to take locks, etc. 55 // 56 // When class loading is finished, a new entry is added to the dictionary 57 // of the class loader and the placeholder is removed. Note that the protection 58 // domain field of the dictionary entry has not yet been filled in when 59 // the "real" dictionary entry is created. 60 // 61 // Clients of this class who are interested in finding if a class has 62 // been completely loaded -- not classes in the process of being loaded -- 63 // can read the dictionary unlocked. This is safe because 64 // - entries are only deleted at safepoints 65 // - readers cannot come to a safepoint while actively examining 66 // an entry (an entry cannot be deleted from under a reader) 67 // - entries must be fully formed before they are available to concurrent 68 // readers (we must ensure write ordering) 69 // 70 // Note that placeholders are deleted at any time, as they are removed 71 // when a class is completely loaded. Therefore, readers as well as writers 72 // of placeholders must hold the SystemDictionary_lock. 73 // 74 75 class ClassFileStream; 76 class Dictionary; 77 class PlaceholderTable; 78 class LoaderConstraintTable; 79 template <MEMFLAGS F> class HashtableBucket; 80 class ResolutionErrorTable; 81 class SymbolPropertyTable; 82 class ProtectionDomainCacheTable; 83 class ProtectionDomainCacheEntry; 84 class GCTimer; 85 class OopStorage; 86 87 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 88 89 // Certain classes, such as java.lang.Object and java.lang.String, 90 // are "well-known", in the sense that no class loader is allowed 91 // to provide a different definition. 92 // 93 // Each well-known class has a short klass name (like object_klass), 94 // and a vmSymbol name (like java_lang_Object). 95 // 96 // The order of these definitions is significant: the classes are 97 // resolved during early VM start-up by resolve_well_known_classes 98 // in this order. Changing the order may require careful restructuring 99 // of the VM start-up sequence. 100 // 101 #define WK_KLASSES_DO(do_klass) \ 102 /* well-known classes */ \ 103 do_klass(Object_klass, java_lang_Object ) \ 104 do_klass(String_klass, java_lang_String ) \ 105 do_klass(Class_klass, java_lang_Class ) \ 106 do_klass(Cloneable_klass, java_lang_Cloneable ) \ 107 do_klass(ClassLoader_klass, java_lang_ClassLoader ) \ 108 do_klass(Serializable_klass, java_io_Serializable ) \ 109 do_klass(System_klass, java_lang_System ) \ 110 do_klass(Throwable_klass, java_lang_Throwable ) \ 111 do_klass(Error_klass, java_lang_Error ) \ 112 do_klass(ThreadDeath_klass, java_lang_ThreadDeath ) \ 113 do_klass(Exception_klass, java_lang_Exception ) \ 114 do_klass(RuntimeException_klass, java_lang_RuntimeException ) \ 115 do_klass(SecurityManager_klass, java_lang_SecurityManager ) \ 116 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain ) \ 117 do_klass(AccessControlContext_klass, java_security_AccessControlContext ) \ 118 do_klass(AccessController_klass, java_security_AccessController ) \ 119 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader ) \ 120 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException ) \ 121 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError ) \ 122 do_klass(LinkageError_klass, java_lang_LinkageError ) \ 123 do_klass(ClassCastException_klass, java_lang_ClassCastException ) \ 124 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException ) \ 125 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError ) \ 126 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError ) \ 127 do_klass(StackOverflowError_klass, java_lang_StackOverflowError ) \ 128 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException ) \ 129 do_klass(Reference_klass, java_lang_ref_Reference ) \ 130 \ 131 /* ref klasses and set reference types */ \ 132 do_klass(SoftReference_klass, java_lang_ref_SoftReference ) \ 133 do_klass(WeakReference_klass, java_lang_ref_WeakReference ) \ 134 do_klass(FinalReference_klass, java_lang_ref_FinalReference ) \ 135 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference ) \ 136 do_klass(Finalizer_klass, java_lang_ref_Finalizer ) \ 137 \ 138 do_klass(Thread_klass, java_lang_Thread ) \ 139 do_klass(ThreadGroup_klass, java_lang_ThreadGroup ) \ 140 do_klass(Properties_klass, java_util_Properties ) \ 141 do_klass(Module_klass, java_lang_Module ) \ 142 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject ) \ 143 do_klass(reflect_Field_klass, java_lang_reflect_Field ) \ 144 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter ) \ 145 do_klass(reflect_Method_klass, java_lang_reflect_Method ) \ 146 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor ) \ 147 \ 148 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 149 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 150 do_klass(reflect_MagicAccessorImpl_klass, reflect_MagicAccessorImpl ) \ 151 do_klass(reflect_MethodAccessorImpl_klass, reflect_MethodAccessorImpl ) \ 152 do_klass(reflect_ConstructorAccessorImpl_klass, reflect_ConstructorAccessorImpl ) \ 153 do_klass(reflect_DelegatingClassLoader_klass, reflect_DelegatingClassLoader ) \ 154 do_klass(reflect_ConstantPool_klass, reflect_ConstantPool ) \ 155 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, reflect_UnsafeStaticFieldAccessorImpl ) \ 156 do_klass(reflect_CallerSensitive_klass, reflect_CallerSensitive ) \ 157 \ 158 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 159 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle ) \ 160 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle ) \ 161 do_klass(VarHandle_klass, java_lang_invoke_VarHandle ) \ 162 do_klass(MemberName_klass, java_lang_invoke_MemberName ) \ 163 do_klass(ResolvedMethodName_klass, java_lang_invoke_ResolvedMethodName ) \ 164 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives ) \ 165 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm ) \ 166 do_klass(MethodType_klass, java_lang_invoke_MethodType ) \ 167 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError ) \ 168 do_klass(CallSite_klass, java_lang_invoke_CallSite ) \ 169 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext ) \ 170 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite ) \ 171 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite ) \ 172 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite ) \ 173 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 174 \ 175 do_klass(AssertionStatusDirectives_klass, java_lang_AssertionStatusDirectives ) \ 176 do_klass(StringBuffer_klass, java_lang_StringBuffer ) \ 177 do_klass(StringBuilder_klass, java_lang_StringBuilder ) \ 178 do_klass(internal_Unsafe_klass, jdk_internal_misc_Unsafe ) \ 179 do_klass(module_Modules_klass, jdk_internal_module_Modules ) \ 180 \ 181 /* support for CDS */ \ 182 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream ) \ 183 do_klass(URL_klass, java_net_URL ) \ 184 do_klass(Jar_Manifest_klass, java_util_jar_Manifest ) \ 185 do_klass(jdk_internal_loader_ClassLoaders_klass, jdk_internal_loader_ClassLoaders ) \ 186 do_klass(jdk_internal_loader_ClassLoaders_AppClassLoader_klass, jdk_internal_loader_ClassLoaders_AppClassLoader) \ 187 do_klass(jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass, jdk_internal_loader_ClassLoaders_PlatformClassLoader) \ 188 do_klass(CodeSource_klass, java_security_CodeSource ) \ 189 \ 190 do_klass(StackTraceElement_klass, java_lang_StackTraceElement ) \ 191 \ 192 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 193 do_klass(nio_Buffer_klass, java_nio_Buffer ) \ 194 \ 195 /* Stack Walking */ \ 196 do_klass(StackWalker_klass, java_lang_StackWalker ) \ 197 do_klass(AbstractStackWalker_klass, java_lang_StackStreamFactory_AbstractStackWalker ) \ 198 do_klass(StackFrameInfo_klass, java_lang_StackFrameInfo ) \ 199 do_klass(LiveStackFrameInfo_klass, java_lang_LiveStackFrameInfo ) \ 200 \ 201 /* support for stack dump lock analysis */ \ 202 do_klass(java_util_concurrent_locks_AbstractOwnableSynchronizer_klass, java_util_concurrent_locks_AbstractOwnableSynchronizer) \ 203 \ 204 /* boxing klasses */ \ 205 do_klass(Boolean_klass, java_lang_Boolean ) \ 206 do_klass(Character_klass, java_lang_Character ) \ 207 do_klass(Float_klass, java_lang_Float ) \ 208 do_klass(Double_klass, java_lang_Double ) \ 209 do_klass(Byte_klass, java_lang_Byte ) \ 210 do_klass(Short_klass, java_lang_Short ) \ 211 do_klass(Integer_klass, java_lang_Integer ) \ 212 do_klass(Long_klass, java_lang_Long ) \ 213 \ 214 /*end*/ 215 216 217 class SystemDictionary : AllStatic { 218 friend class VMStructs; 219 friend class SystemDictionaryHandles; 220 221 public: 222 enum WKID { 223 NO_WKID = 0, 224 225 #define WK_KLASS_ENUM(name, symbol) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 226 WK_KLASSES_DO(WK_KLASS_ENUM) 227 #undef WK_KLASS_ENUM 228 229 WKID_LIMIT, 230 231 FIRST_WKID = NO_WKID + 1 232 }; 233 234 // Returns a class with a given class name and class loader. Loads the 235 // class if needed. If not found a NoClassDefFoundError or a 236 // ClassNotFoundException is thrown, depending on the value on the 237 // throw_error flag. For most uses the throw_error argument should be set 238 // to true. 239 240 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 241 // Convenient call for null loader and protection domain. 242 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 243 protected: 244 // handle error translation for resolve_or_null results 245 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, Klass* klass, TRAPS); 246 247 public: 248 249 // Returns a class with a given class name and class loader. 250 // Loads the class if needed. If not found NULL is returned. 251 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 252 // Version with null loader and protection domain 253 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 254 255 // Resolve a superclass or superinterface. Called from ClassFileParser, 256 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 257 // "child_name" is the class whose super class or interface is being resolved. 258 static InstanceKlass* resolve_super_or_fail(Symbol* child_name, 259 Symbol* class_name, 260 Handle class_loader, 261 Handle protection_domain, 262 bool is_superclass, 263 TRAPS); 264 265 // Parse new stream. This won't update the dictionary or 266 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 267 // Also used by Unsafe_DefineAnonymousClass 268 static InstanceKlass* parse_stream(Symbol* class_name, 269 Handle class_loader, 270 Handle protection_domain, 271 ClassFileStream* st, 272 TRAPS) { 273 return parse_stream(class_name, 274 class_loader, 275 protection_domain, 276 st, 277 NULL, // unsafe_anonymous_host 278 NULL, // cp_patches 279 THREAD); 280 } 281 static InstanceKlass* parse_stream(Symbol* class_name, 282 Handle class_loader, 283 Handle protection_domain, 284 ClassFileStream* st, 285 const InstanceKlass* unsafe_anonymous_host, 286 GrowableArray<Handle>* cp_patches, 287 TRAPS); 288 289 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 290 static InstanceKlass* resolve_from_stream(Symbol* class_name, 291 Handle class_loader, 292 Handle protection_domain, 293 ClassFileStream* st, 294 TRAPS); 295 296 // Lookup an already loaded class. If not found NULL is returned. 297 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 298 299 // Lookup an already loaded instance or array class. 300 // Do not make any queries to class loaders; consult only the cache. 301 // If not found NULL is returned. 302 static Klass* find_instance_or_array_klass(Symbol* class_name, 303 Handle class_loader, 304 Handle protection_domain, 305 TRAPS); 306 307 // Lookup an instance or array class that has already been loaded 308 // either into the given class loader, or else into another class 309 // loader that is constrained (via loader constraints) to produce 310 // a consistent class. Do not take protection domains into account. 311 // Do not make any queries to class loaders; consult only the cache. 312 // Return NULL if the class is not found. 313 // 314 // This function is a strict superset of find_instance_or_array_klass. 315 // This function (the unchecked version) makes a conservative prediction 316 // of the result of the checked version, assuming successful lookup. 317 // If both functions return non-null, they must return the same value. 318 // Also, the unchecked version may sometimes be non-null where the 319 // checked version is null. This can occur in several ways: 320 // 1. No query has yet been made to the class loader. 321 // 2. The class loader was queried, but chose not to delegate. 322 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 323 // 4. Loading was attempted, but there was a linkage error of some sort. 324 // In all of these cases, the loader constraints on this type are 325 // satisfied, and it is safe for classes in the given class loader 326 // to manipulate strongly-typed values of the found class, subject 327 // to local linkage and access checks. 328 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 329 Handle class_loader, 330 TRAPS); 331 332 static void classes_do(MetaspaceClosure* it); 333 // Iterate over all methods in all klasses 334 335 static void methods_do(void f(Method*)); 336 337 // Garbage collection support 338 339 // Unload (that is, break root links to) all unmarked classes and 340 // loaders. Returns "true" iff something was unloaded. 341 static bool do_unloading(GCTimer* gc_timer); 342 343 // Applies "f->do_oop" to all root oops in the system dictionary. 344 static void oops_do(OopClosure* f); 345 346 // System loader lock 347 static oop system_loader_lock() { return _system_loader_lock_obj; } 348 349 // Protection Domain Table 350 static ProtectionDomainCacheTable* pd_cache_table() { return _pd_cache_table; } 351 352 public: 353 // Printing 354 static void print() { return print_on(tty); } 355 static void print_on(outputStream* st); 356 static void dump(outputStream* st, bool verbose); 357 358 // Monotonically increasing counter which grows as classes are 359 // loaded or modifications such as hot-swapping or setting/removing 360 // of breakpoints are performed 361 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 362 // Needed by evolution and breakpoint code 363 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 364 365 // Verification 366 static void verify(); 367 368 // Initialization 369 static void initialize(TRAPS); 370 371 // Checked fast access to the well-known classes -- so that you don't try to use them 372 // before they are resolved. 373 static InstanceKlass* check_klass(InstanceKlass* k) { 374 assert(k != NULL, "klass not loaded"); 375 return k; 376 } 377 378 static bool resolve_wk_klass(WKID id, TRAPS); 379 static void resolve_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 380 static void resolve_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 381 int limit = (int)end_id + 1; 382 resolve_wk_klasses_until((WKID) limit, start_id, THREAD); 383 } 384 385 public: 386 #define WK_KLASS_DECLARE(name, symbol) \ 387 static InstanceKlass* name() { return check_klass(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 388 static InstanceKlass** name##_addr() { \ 389 return &_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 390 } \ 391 static bool name##_is_loaded() { \ 392 return _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] != NULL; \ 393 } 394 WK_KLASSES_DO(WK_KLASS_DECLARE); 395 #undef WK_KLASS_DECLARE 396 397 static InstanceKlass* well_known_klass(WKID id) { 398 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 399 return _well_known_klasses[id]; 400 } 401 402 static InstanceKlass** well_known_klass_addr(WKID id) { 403 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 404 return &_well_known_klasses[id]; 405 } 406 static void well_known_klasses_do(MetaspaceClosure* it); 407 408 // Local definition for direct access to the private array: 409 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 410 411 static InstanceKlass* box_klass(BasicType t) { 412 assert((uint)t < T_VOID+1, "range check"); 413 return check_klass(_box_klasses[t]); 414 } 415 static BasicType box_klass_type(Klass* k); // inverse of box_klass 416 #ifdef ASSERT 417 static bool is_well_known_klass(Klass* k) { 418 return is_well_known_klass(k->name()); 419 } 420 static bool is_well_known_klass(Symbol* class_name); 421 #endif 422 423 protected: 424 // Returns the class loader data to be used when looking up/updating the 425 // system dictionary. 426 static ClassLoaderData *class_loader_data(Handle class_loader) { 427 return ClassLoaderData::class_loader_data(class_loader()); 428 } 429 430 public: 431 // Tells whether ClassLoader.checkPackageAccess is present 432 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 433 434 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 435 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 436 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 437 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 438 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 439 440 // Returns java system loader 441 static oop java_system_loader(); 442 443 // Returns java platform loader 444 static oop java_platform_loader(); 445 446 // Compute the java system and platform loaders 447 static void compute_java_loaders(TRAPS); 448 449 // Register a new class loader 450 static ClassLoaderData* register_loader(Handle class_loader); 451 protected: 452 // Mirrors for primitive classes (created eagerly) 453 static oop check_mirror(oop m) { 454 assert(m != NULL, "mirror not initialized"); 455 return m; 456 } 457 458 public: 459 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 460 461 // Check class loader constraints 462 static bool add_loader_constraint(Symbol* name, Handle loader1, 463 Handle loader2, TRAPS); 464 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 465 Handle loader2, bool is_method, TRAPS); 466 467 // JSR 292 468 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 469 // (asks Java to compute it if necessary, except in a compiler thread) 470 static methodHandle find_method_handle_invoker(Klass* klass, 471 Symbol* name, 472 Symbol* signature, 473 Klass* accessing_klass, 474 Handle *appendix_result, 475 TRAPS); 476 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 477 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 478 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 479 Symbol* signature, 480 TRAPS); 481 482 // compute java_mirror (java.lang.Class instance) for a type ("I", "[[B", "LFoo;", etc.) 483 // Either the accessing_klass or the CL/PD can be non-null, but not both. 484 static Handle find_java_mirror_for_type(Symbol* signature, 485 Klass* accessing_klass, 486 Handle class_loader, 487 Handle protection_domain, 488 SignatureStream::FailureMode failure_mode, 489 TRAPS); 490 static Handle find_java_mirror_for_type(Symbol* signature, 491 Klass* accessing_klass, 492 SignatureStream::FailureMode failure_mode, 493 TRAPS) { 494 // callee will fill in CL/PD from AK, if they are needed 495 return find_java_mirror_for_type(signature, accessing_klass, Handle(), Handle(), 496 failure_mode, THREAD); 497 } 498 499 500 // fast short-cut for the one-character case: 501 static oop find_java_mirror_for_type(char signature_char); 502 503 // find a java.lang.invoke.MethodType object for a given signature 504 // (asks Java to compute it if necessary, except in a compiler thread) 505 static Handle find_method_handle_type(Symbol* signature, 506 Klass* accessing_klass, 507 TRAPS); 508 509 // find a java.lang.Class object for a given signature 510 static Handle find_field_handle_type(Symbol* signature, 511 Klass* accessing_klass, 512 TRAPS); 513 514 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 515 static Handle link_method_handle_constant(Klass* caller, 516 int ref_kind, //e.g., JVM_REF_invokeVirtual 517 Klass* callee, 518 Symbol* name, 519 Symbol* signature, 520 TRAPS); 521 522 // ask Java to compute a constant by invoking a BSM given a Dynamic_info CP entry 523 static Handle link_dynamic_constant(Klass* caller, 524 int condy_index, 525 Handle bootstrap_specifier, 526 Symbol* name, 527 Symbol* type, 528 TRAPS); 529 530 // ask Java to create a dynamic call site, while linking an invokedynamic op 531 static methodHandle find_dynamic_call_site_invoker(Klass* caller, 532 int indy_index, 533 Handle bootstrap_method, 534 Symbol* name, 535 Symbol* type, 536 Handle *appendix_result, 537 TRAPS); 538 539 // Record the error when the first attempt to resolve a reference from a constant 540 // pool entry to a class fails. 541 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error, 542 Symbol* message); 543 static void delete_resolution_error(ConstantPool* pool); 544 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which, 545 Symbol** message); 546 547 548 static ProtectionDomainCacheEntry* cache_get(Handle protection_domain); 549 550 protected: 551 552 enum Constants { 553 _loader_constraint_size = 107, // number of entries in constraint table 554 _resolution_error_size = 107, // number of entries in resolution error table 555 _invoke_method_size = 139, // number of entries in invoke method table 556 _placeholder_table_size = 1009 // number of entries in hash table for placeholders 557 }; 558 559 560 // Static tables owned by the SystemDictionary 561 562 // Hashtable holding placeholders for classes being loaded. 563 static PlaceholderTable* _placeholders; 564 565 // Monotonically increasing counter which grows with 566 // loading classes as well as hot-swapping and breakpoint setting 567 // and removal. 568 static int _number_of_modifications; 569 570 // Lock object for system class loader 571 static oop _system_loader_lock_obj; 572 573 // Constraints on class loaders 574 static LoaderConstraintTable* _loader_constraints; 575 576 // Resolution errors 577 static ResolutionErrorTable* _resolution_errors; 578 579 // Invoke methods (JSR 292) 580 static SymbolPropertyTable* _invoke_method_table; 581 582 // ProtectionDomain cache 583 static ProtectionDomainCacheTable* _pd_cache_table; 584 585 // VM weak OopStorage object. 586 static OopStorage* _vm_weak_oop_storage; 587 588 protected: 589 static void validate_protection_domain(InstanceKlass* klass, 590 Handle class_loader, 591 Handle protection_domain, TRAPS); 592 593 friend class VM_PopulateDumpSharedSpace; 594 friend class TraversePlaceholdersClosure; 595 static PlaceholderTable* placeholders() { return _placeholders; } 596 static LoaderConstraintTable* constraints() { return _loader_constraints; } 597 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 598 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 599 600 // Basic loading operations 601 static InstanceKlass* resolve_instance_class_or_null_helper(Symbol* name, 602 Handle class_loader, 603 Handle protection_domain, 604 TRAPS); 605 static InstanceKlass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 606 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 607 static InstanceKlass* handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 608 // Wait on SystemDictionary_lock; unlocks lockObject before 609 // waiting; relocks lockObject with correct recursion count 610 // after waiting, but before reentering SystemDictionary_lock 611 // to preserve lock order semantics. 612 static void double_lock_wait(Handle lockObject, TRAPS); 613 static void define_instance_class(InstanceKlass* k, TRAPS); 614 static InstanceKlass* find_or_define_instance_class(Symbol* class_name, 615 Handle class_loader, 616 InstanceKlass* k, TRAPS); 617 static bool is_shared_class_visible(Symbol* class_name, InstanceKlass* ik, 618 Handle class_loader, TRAPS); 619 static InstanceKlass* load_shared_class(InstanceKlass* ik, 620 Handle class_loader, 621 Handle protection_domain, 622 const ClassFileStream *cfs, 623 TRAPS); 624 static InstanceKlass* load_shared_boot_class(Symbol* class_name, 625 TRAPS); 626 static InstanceKlass* load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 627 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 628 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 629 static bool is_parallelCapable(Handle class_loader); 630 static bool is_parallelDefine(Handle class_loader); 631 632 public: 633 static bool is_system_class_loader(oop class_loader); 634 static bool is_platform_class_loader(oop class_loader); 635 636 // Returns TRUE if the method is a non-public member of class java.lang.Object. 637 static bool is_nonpublic_Object_method(Method* m) { 638 assert(m != NULL, "Unexpected NULL Method*"); 639 return !m->is_public() && m->method_holder() == SystemDictionary::Object_klass(); 640 } 641 642 static void initialize_oop_storage(); 643 static OopStorage* vm_weak_oop_storage(); 644 645 protected: 646 // Setup link to hierarchy 647 static void add_to_hierarchy(InstanceKlass* k, TRAPS); 648 649 // Basic find on loaded classes 650 static InstanceKlass* find_class(unsigned int hash, 651 Symbol* name, Dictionary* dictionary); 652 static InstanceKlass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 653 654 // Basic find on classes in the midst of being loaded 655 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 656 657 // Add a placeholder for a class being loaded 658 static void add_placeholder(int index, 659 Symbol* class_name, 660 ClassLoaderData* loader_data); 661 static void remove_placeholder(int index, 662 Symbol* class_name, 663 ClassLoaderData* loader_data); 664 665 // Performs cleanups after resolve_super_or_fail. This typically needs 666 // to be called on failure. 667 // Won't throw, but can block. 668 static void resolution_cleanups(Symbol* class_name, 669 ClassLoaderData* loader_data, 670 TRAPS); 671 672 // Resolve well-known classes so they can be used like SystemDictionary::String_klass() 673 static void resolve_well_known_classes(TRAPS); 674 675 // Class loader constraints 676 static void check_constraints(unsigned int hash, 677 InstanceKlass* k, Handle loader, 678 bool defining, TRAPS); 679 static void update_dictionary(unsigned int d_hash, 680 int p_index, unsigned int p_hash, 681 InstanceKlass* k, Handle loader, 682 TRAPS); 683 684 static InstanceKlass* _well_known_klasses[]; 685 686 // table of box klasses (int_klass, etc.) 687 static InstanceKlass* _box_klasses[T_VOID+1]; 688 689 private: 690 static oop _java_system_loader; 691 static oop _java_platform_loader; 692 693 static bool _has_checkPackageAccess; 694 }; 695 696 #endif // SHARE_CLASSFILE_SYSTEMDICTIONARY_HPP