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