1 /* 2 * Copyright (c) 1997, 2016, 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 "classfile/systemDictionary_ext.hpp" 30 #include "jvmci/systemDictionary_jvmci.hpp" 31 #include "oops/objArrayOop.hpp" 32 #include "oops/symbol.hpp" 33 #include "runtime/java.hpp" 34 #include "runtime/reflectionUtils.hpp" 35 #include "utilities/hashtable.hpp" 36 #include "utilities/hashtable.inline.hpp" 37 38 // The system dictionary stores all loaded classes and maps: 39 // 40 // [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass* 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 with a fixed number 46 // of buckets. During loading the loader object is locked, (for the VM loader 47 // a private lock object is used). Class loading can thus be done concurrently, 48 // but only by different loaders. 49 // 50 // During loading a placeholder (name, loader) is temporarily placed in 51 // a side data structure, and is used to detect ClassCircularityErrors 52 // and to perform verification during GC. A GC can occur in the midst 53 // of class loading, as we call out to Java, have to take locks, etc. 54 // 55 // When class loading is finished, a new entry is added to the system 56 // dictionary and the place holder is removed. Note that the protection 57 // domain field of the system dictionary has not yet been filled in when 58 // the "real" system dictionary entry is created. 59 // 60 // Clients of this class who are interested in finding if a class has 61 // been completely loaded -- not classes in the process of being loaded -- 62 // can read the SystemDictionary unlocked. This is safe because 63 // - entries are only deleted at safepoints 64 // - readers cannot come to a safepoint while actively examining 65 // an entry (an entry cannot be deleted from under a reader) 66 // - entries must be fully formed before they are available to concurrent 67 // readers (we must ensure write ordering) 68 // 69 // Note that placeholders are deleted at any time, as they are removed 70 // when a class is completely loaded. Therefore, readers as well as writers 71 // of placeholders must hold the SystemDictionary_lock. 72 // 73 74 class ClassFileStream; 75 class Dictionary; 76 class PlaceholderTable; 77 class LoaderConstraintTable; 78 template <MEMFLAGS F> class HashtableBucket; 79 class ResolutionErrorTable; 80 class SymbolPropertyTable; 81 82 // Certain classes are preloaded, such as java.lang.Object and java.lang.String. 83 // They are all "well-known", in the sense that no class loader is allowed 84 // to provide a different definition. 85 // 86 // These klasses must all have names defined in vmSymbols. 87 88 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 89 90 // Each well-known class has a short klass name (like object_klass), 91 // a vmSymbol name (like java_lang_Object), and a flag word 92 // that makes some minor distinctions, like whether the klass 93 // is preloaded, optional, release-specific, etc. 94 // The order of these definitions is significant; it is the order in which 95 // preloading is actually performed by initialize_preloaded_classes. 96 97 #define WK_KLASSES_DO(do_klass) \ 98 /* well-known classes */ \ 99 do_klass(Object_klass, java_lang_Object, Pre ) \ 100 do_klass(String_klass, java_lang_String, Pre ) \ 101 do_klass(Class_klass, java_lang_Class, Pre ) \ 102 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \ 103 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \ 104 do_klass(Serializable_klass, java_io_Serializable, Pre ) \ 105 do_klass(System_klass, java_lang_System, Pre ) \ 106 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \ 107 do_klass(Error_klass, java_lang_Error, Pre ) \ 108 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \ 109 do_klass(Exception_klass, java_lang_Exception, Pre ) \ 110 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \ 111 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \ 112 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \ 113 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \ 114 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \ 115 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \ 116 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \ 117 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \ 118 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \ 119 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \ 120 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \ 121 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \ 122 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \ 123 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \ 124 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \ 125 \ 126 /* Preload ref klasses and set reference types */ \ 127 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \ 128 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \ 129 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \ 130 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \ 131 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \ 132 \ 133 do_klass(Thread_klass, java_lang_Thread, Pre ) \ 134 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \ 135 do_klass(Properties_klass, java_util_Properties, Pre ) \ 136 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \ 137 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \ 138 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \ 139 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \ 140 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \ 141 \ 142 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 143 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 144 do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \ 145 do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Pre ) \ 146 do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Pre ) \ 147 do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \ 148 do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt ) \ 149 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt ) \ 150 do_klass(reflect_CallerSensitive_klass, sun_reflect_CallerSensitive, Opt ) \ 151 \ 152 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 153 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \ 154 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \ 155 do_klass(VarHandle_klass, java_lang_invoke_VarHandle, Pre ) \ 156 do_klass(FieldHandle_klass, java_lang_invoke_FieldHandle, Pre ) \ 157 do_klass(ArrayHandle_klass, java_lang_invoke_ArrayHandle, Pre ) \ 158 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \ 159 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \ 160 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \ 161 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \ 162 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \ 163 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \ 164 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre ) \ 165 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \ 166 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \ 167 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \ 168 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 169 \ 170 do_klass(ArrayImpl_klass, java_lang_ArrayImpl, Opt ) \ 171 \ 172 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \ 173 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \ 174 do_klass(internal_Unsafe_klass, jdk_internal_misc_Unsafe, Pre ) \ 175 \ 176 /* support for CDS */ \ 177 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \ 178 do_klass(File_klass, java_io_File, Pre ) \ 179 do_klass(URLClassLoader_klass, java_net_URLClassLoader, Pre ) \ 180 do_klass(URL_klass, java_net_URL, Pre ) \ 181 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \ 182 do_klass(sun_misc_Launcher_klass, sun_misc_Launcher, Pre ) \ 183 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \ 184 \ 185 /* Support for valhalla specializer */ \ 186 do_klass(Valhalla_Specializer_klass, valhalla_classdyn_ClassDynHelper, Pre ) \ 187 \ 188 /* support for valhalla "shady" value type bytecode transformer */ \ 189 do_klass(DeriveValueType_klass, jvm_internal_value_DeriveValueType, Pre ) \ 190 do_klass(Valhalla_MVT1_0_klass, valhalla_shady_MVT1_0, Pre ) \ 191 \ 192 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 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, Opt ) \ 196 \ 197 /* Stack Walking */ \ 198 do_klass(StackWalker_klass, java_lang_StackWalker, Opt ) \ 199 do_klass(AbstractStackWalker_klass, java_lang_StackStreamFactory_AbstractStackWalker, Opt ) \ 200 do_klass(StackFrameInfo_klass, java_lang_StackFrameInfo, Opt ) \ 201 do_klass(LiveStackFrameInfo_klass, java_lang_LiveStackFrameInfo, Opt ) \ 202 \ 203 /* Preload boxing klasses */ \ 204 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \ 205 do_klass(Character_klass, java_lang_Character, Pre ) \ 206 do_klass(Float_klass, java_lang_Float, Pre ) \ 207 do_klass(Double_klass, java_lang_Double, Pre ) \ 208 do_klass(Byte_klass, java_lang_Byte, Pre ) \ 209 do_klass(Short_klass, java_lang_Short, Pre ) \ 210 do_klass(Integer_klass, java_lang_Integer, Pre ) \ 211 do_klass(Long_klass, java_lang_Long, Pre ) \ 212 \ 213 do_klass(___Value_klass, java_lang____Value, Pre ) \ 214 \ 215 /* Extensions */ \ 216 WK_KLASSES_DO_EXT(do_klass) \ 217 /* JVMCI classes. These are loaded on-demand. */ \ 218 JVMCI_WK_KLASSES_DO(do_klass) \ 219 \ 220 /*end*/ 221 222 223 class SystemDictionary : AllStatic { 224 friend class VMStructs; 225 friend class SystemDictionaryHandles; 226 friend class SharedClassUtil; 227 228 public: 229 enum WKID { 230 NO_WKID = 0, 231 232 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 233 WK_KLASSES_DO(WK_KLASS_ENUM) 234 #undef WK_KLASS_ENUM 235 236 WKID_LIMIT, 237 238 #if INCLUDE_JVMCI 239 FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(HotSpotCompiledCode_klass), 240 LAST_JVMCI_WKID = WK_KLASS_ENUM_NAME(Value_klass), 241 #endif 242 243 FIRST_WKID = NO_WKID + 1 244 }; 245 246 enum InitOption { 247 Pre, // preloaded; error if not present 248 249 // Order is significant. Options before this point require resolve_or_fail. 250 // Options after this point will use resolve_or_null instead. 251 252 Opt, // preload tried; NULL if not present 253 #if INCLUDE_JVMCI 254 Jvmci, // preload tried; error if not present, use only with JVMCI 255 #endif 256 OPTION_LIMIT, 257 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 258 }; 259 260 261 // Returns a class with a given class name and class loader. Loads the 262 // class if needed. If not found a NoClassDefFoundError or a 263 // ClassNotFoundException is thrown, depending on the value on the 264 // throw_error flag. For most uses the throw_error argument should be set 265 // to true. 266 267 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 268 // Convenient call for null loader and protection domain. 269 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 270 protected: 271 // handle error translation for resolve_or_null results 272 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, KlassHandle klass_h, TRAPS); 273 274 public: 275 276 // Returns a class with a given class name and class loader. 277 // Loads the class if needed. If not found NULL is returned. 278 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 279 // Version with null loader and protection domain 280 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 281 282 // Resolve a superclass or superinterface. Called from ClassFileParser, 283 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 284 // "child_name" is the class whose super class or interface is being resolved. 285 static Klass* resolve_super_or_fail(Symbol* child_name, 286 Symbol* class_name, 287 Handle class_loader, 288 Handle protection_domain, 289 bool is_superclass, 290 TRAPS); 291 292 // Parse new stream. This won't update the system dictionary or 293 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 294 static Klass* parse_stream(Symbol* class_name, 295 Handle class_loader, 296 Handle protection_domain, 297 ClassFileStream* st, 298 TRAPS) { 299 return parse_stream(class_name, 300 class_loader, 301 protection_domain, 302 st, 303 NULL, // host klass 304 NULL, // cp_patches 305 THREAD); 306 } 307 static Klass* parse_stream(Symbol* class_name, 308 Handle class_loader, 309 Handle protection_domain, 310 ClassFileStream* st, 311 const Klass* host_klass, 312 GrowableArray<Handle>* cp_patches, 313 TRAPS); 314 315 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 316 static Klass* resolve_from_stream(Symbol* class_name, 317 Handle class_loader, 318 Handle protection_domain, 319 ClassFileStream* st, 320 TRAPS); 321 322 // Lookup an already loaded class. If not found NULL is returned. 323 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 324 325 // Lookup an already loaded instance or array class. 326 // Do not make any queries to class loaders; consult only the cache. 327 // If not found NULL is returned. 328 static Klass* find_instance_or_array_klass(Symbol* class_name, 329 Handle class_loader, 330 Handle protection_domain, 331 TRAPS); 332 333 // Lookup an instance or array class that has already been loaded 334 // either into the given class loader, or else into another class 335 // loader that is constrained (via loader constraints) to produce 336 // a consistent class. Do not take protection domains into account. 337 // Do not make any queries to class loaders; consult only the cache. 338 // Return NULL if the class is not found. 339 // 340 // This function is a strict superset of find_instance_or_array_klass. 341 // This function (the unchecked version) makes a conservative prediction 342 // of the result of the checked version, assuming successful lookup. 343 // If both functions return non-null, they must return the same value. 344 // Also, the unchecked version may sometimes be non-null where the 345 // checked version is null. This can occur in several ways: 346 // 1. No query has yet been made to the class loader. 347 // 2. The class loader was queried, but chose not to delegate. 348 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 349 // 4. Loading was attempted, but there was a linkage error of some sort. 350 // In all of these cases, the loader constraints on this type are 351 // satisfied, and it is safe for classes in the given class loader 352 // to manipulate strongly-typed values of the found class, subject 353 // to local linkage and access checks. 354 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 355 Handle class_loader, 356 TRAPS); 357 358 // Iterate over all klasses in dictionary 359 // Just the classes from defining class loaders 360 static void classes_do(void f(Klass*)); 361 // Added for initialize_itable_for_klass to handle exceptions 362 static void classes_do(void f(Klass*, TRAPS), TRAPS); 363 // All classes, and their class loaders 364 static void classes_do(void f(Klass*, ClassLoaderData*)); 365 366 static void placeholders_do(void f(Symbol*)); 367 368 // Iterate over all methods in all klasses in dictionary 369 static void methods_do(void f(Method*)); 370 371 // Garbage collection support 372 373 // This method applies "blk->do_oop" to all the pointers to "system" 374 // classes and loaders. 375 static void always_strong_oops_do(OopClosure* blk); 376 static void always_strong_classes_do(KlassClosure* closure); 377 378 // Unload (that is, break root links to) all unmarked classes and 379 // loaders. Returns "true" iff something was unloaded. 380 static bool do_unloading(BoolObjectClosure* is_alive, 381 bool clean_previous_versions = true); 382 383 // Used by DumpSharedSpaces only to remove classes that failed verification 384 static void remove_classes_in_error_state(); 385 386 static int calculate_systemdictionary_size(int loadedclasses); 387 388 // Applies "f->do_oop" to all root oops in the system dictionary. 389 static void oops_do(OopClosure* f); 390 static void roots_oops_do(OopClosure* strong, OopClosure* weak); 391 392 // System loader lock 393 static oop system_loader_lock() { return _system_loader_lock_obj; } 394 395 protected: 396 // Extended Redefine classes support (tbi) 397 static void preloaded_classes_do(KlassClosure* f); 398 static void lazily_loaded_classes_do(KlassClosure* f); 399 public: 400 // Sharing support. 401 static void reorder_dictionary(); 402 static void copy_buckets(char** top, char* end); 403 static void copy_table(char** top, char* end); 404 static void reverse(); 405 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 406 int number_of_entries); 407 // Printing 408 static void print(bool details = true); 409 static void print_shared(bool details = true); 410 411 // Number of contained klasses 412 // This is both fully loaded classes and classes in the process 413 // of being loaded 414 static int number_of_classes(); 415 416 // Monotonically increasing counter which grows as classes are 417 // loaded or modifications such as hot-swapping or setting/removing 418 // of breakpoints are performed 419 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 420 // Needed by evolution and breakpoint code 421 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 422 423 // Verification 424 static void verify(); 425 426 #ifdef ASSERT 427 static bool is_internal_format(Symbol* class_name); 428 #endif 429 430 // Initialization 431 static void initialize(TRAPS); 432 static void load_array_interfaces(TRAPS); 433 434 // Fast access to commonly used classes (preloaded) 435 static InstanceKlass* check_klass(InstanceKlass* k) { 436 assert(k != NULL, "preloaded klass not initialized"); 437 return k; 438 } 439 440 static InstanceKlass* check_klass_Pre(InstanceKlass* k) { return check_klass(k); } 441 static InstanceKlass* check_klass_Opt(InstanceKlass* k) { return k; } 442 443 JVMCI_ONLY(static InstanceKlass* check_klass_Jvmci(InstanceKlass* k) { return k; }) 444 445 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 446 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 447 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 448 int limit = (int)end_id + 1; 449 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 450 } 451 452 public: 453 #define WK_KLASS_DECLARE(name, symbol, option) \ 454 static InstanceKlass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 455 static InstanceKlass** name##_addr() { \ 456 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 457 } 458 WK_KLASSES_DO(WK_KLASS_DECLARE); 459 #undef WK_KLASS_DECLARE 460 461 static InstanceKlass* well_known_klass(WKID id) { 462 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 463 return _well_known_klasses[id]; 464 } 465 466 static InstanceKlass** well_known_klass_addr(WKID id) { 467 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 468 return &_well_known_klasses[id]; 469 } 470 471 // Local definition for direct access to the private array: 472 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 473 474 static InstanceKlass* box_klass(BasicType t) { 475 assert((uint)t < T_VOID+1, "range check"); 476 return check_klass(_box_klasses[t]); 477 } 478 static BasicType box_klass_type(Klass* k); // inverse of box_klass 479 480 static InstanceKlass* array_interface(BasicType t) { 481 assert((uint)t < T_VOID+1, "range check"); 482 return _array_interfaces[t]; 483 } 484 static BasicType array_interface_type(Klass* k); // inverse of array_interface 485 486 // methods returning lazily loaded klasses 487 // The corresponding method to load the class must be called before calling them. 488 static InstanceKlass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 489 490 static void load_abstract_ownable_synchronizer_klass(TRAPS); 491 492 protected: 493 // Tells whether ClassLoader.loadClassInternal is present 494 static bool has_loadClassInternal() { return _has_loadClassInternal; } 495 496 // Returns the class loader data to be used when looking up/updating the 497 // system dictionary. 498 static ClassLoaderData *class_loader_data(Handle class_loader) { 499 return ClassLoaderData::class_loader_data(class_loader()); 500 } 501 502 public: 503 // Tells whether ClassLoader.checkPackageAccess is present 504 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 505 506 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 507 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 508 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 509 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 510 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 511 static bool ArrayImpl_klass_loaded() { return WK_KLASS(ArrayImpl_klass) != NULL; } 512 513 // Returns default system loader 514 static oop java_system_loader(); 515 516 // Compute the default system loader 517 static void compute_java_system_loader(TRAPS); 518 519 // Register a new class loader 520 static ClassLoaderData* register_loader(Handle class_loader, TRAPS); 521 protected: 522 // Mirrors for primitive classes (created eagerly) 523 static oop check_mirror(oop m) { 524 assert(m != NULL, "mirror not initialized"); 525 return m; 526 } 527 528 public: 529 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 530 531 // Check class loader constraints 532 static bool add_loader_constraint(Symbol* name, Handle loader1, 533 Handle loader2, TRAPS); 534 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 535 Handle loader2, bool is_method, TRAPS); 536 537 // JSR 292 538 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 539 // (asks Java to compute it if necessary, except in a compiler thread) 540 static methodHandle find_method_handle_invoker(Symbol* name, 541 Symbol* signature, 542 KlassHandle accessing_klass, 543 Handle *appendix_result, 544 Handle *method_type_result, 545 TRAPS); 546 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 547 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 548 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 549 Symbol* signature, 550 TRAPS); 551 // find a java.lang.invoke.MethodType object for a given signature 552 // (asks Java to compute it if necessary, except in a compiler thread) 553 static Handle find_method_handle_type(Symbol* signature, 554 KlassHandle accessing_klass, 555 TRAPS); 556 557 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 558 static Handle link_method_handle_constant(KlassHandle caller, 559 int ref_kind, //e.g., JVM_REF_invokeVirtual 560 KlassHandle callee, 561 Symbol* name, 562 Symbol* signature, 563 TRAPS); 564 565 // ask Java to create a dynamic call site, while linking an invokedynamic op 566 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller, 567 Handle bootstrap_method, 568 Symbol* name, 569 Symbol* type, 570 Handle *appendix_result, 571 Handle *method_type_result, 572 TRAPS); 573 574 // Utility for printing loader "name" as part of tracing constraints 575 static const char* loader_name(const oop loader); 576 static const char* loader_name(const ClassLoaderData* loader_data); 577 578 // Record the error when the first attempt to resolve a reference from a constant 579 // pool entry to a class fails. 580 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error, 581 Symbol* message); 582 static void delete_resolution_error(ConstantPool* pool); 583 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which, 584 Symbol** message); 585 586 protected: 587 588 enum Constants { 589 _loader_constraint_size = 107, // number of entries in constraint table 590 _resolution_error_size = 107, // number of entries in resolution error table 591 _invoke_method_size = 139, // number of entries in invoke method table 592 _nof_buckets = 1009, // number of buckets in hash table for placeholders 593 _old_default_sdsize = 1009, // backward compat for system dictionary size 594 _prime_array_size = 8, // array of primes for system dictionary size 595 _average_depth_goal = 3 // goal for lookup length 596 }; 597 598 599 // Static variables 600 601 // hashtable sizes for system dictionary to allow growth 602 // prime numbers for system dictionary size 603 static int _sdgeneration; 604 static const int _primelist[_prime_array_size]; 605 606 // Hashtable holding loaded classes. 607 static Dictionary* _dictionary; 608 609 // Hashtable holding placeholders for classes being loaded. 610 static PlaceholderTable* _placeholders; 611 612 // Hashtable holding classes from the shared archive. 613 static Dictionary* _shared_dictionary; 614 615 // Monotonically increasing counter which grows with 616 // _number_of_classes as well as hot-swapping and breakpoint setting 617 // and removal. 618 static int _number_of_modifications; 619 620 // Lock object for system class loader 621 static oop _system_loader_lock_obj; 622 623 // Constraints on class loaders 624 static LoaderConstraintTable* _loader_constraints; 625 626 // Resolution errors 627 static ResolutionErrorTable* _resolution_errors; 628 629 // Invoke methods (JSR 292) 630 static SymbolPropertyTable* _invoke_method_table; 631 632 public: 633 // for VM_CounterDecay iteration support 634 friend class CounterDecay; 635 static Klass* try_get_next_class(); 636 637 protected: 638 static void validate_protection_domain(instanceKlassHandle klass, 639 Handle class_loader, 640 Handle protection_domain, TRAPS); 641 642 friend class VM_PopulateDumpSharedSpace; 643 friend class TraversePlaceholdersClosure; 644 static Dictionary* dictionary() { return _dictionary; } 645 static Dictionary* shared_dictionary() { return _shared_dictionary; } 646 static PlaceholderTable* placeholders() { return _placeholders; } 647 static LoaderConstraintTable* constraints() { return _loader_constraints; } 648 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 649 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 650 651 // Basic loading operations 652 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 653 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 654 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 655 // Wait on SystemDictionary_lock; unlocks lockObject before 656 // waiting; relocks lockObject with correct recursion count 657 // after waiting, but before reentering SystemDictionary_lock 658 // to preserve lock order semantics. 659 static void double_lock_wait(Handle lockObject, TRAPS); 660 static void define_instance_class(instanceKlassHandle k, TRAPS); 661 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name, 662 Handle class_loader, 663 instanceKlassHandle k, TRAPS); 664 static instanceKlassHandle load_shared_class(instanceKlassHandle ik, 665 Handle class_loader, 666 Handle protection_domain, 667 TRAPS); 668 static instanceKlassHandle 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 instanceKlassHandle load_shared_class(Symbol* class_name, 676 Handle class_loader, 677 TRAPS); 678 static bool is_ext_class_loader(Handle class_loader); 679 680 protected: 681 static Klass* find_shared_class(Symbol* class_name); 682 683 // Setup link to hierarchy 684 static void add_to_hierarchy(instanceKlassHandle k, TRAPS); 685 686 // We pass in the hashtable index so we can calculate it outside of 687 // the SystemDictionary_lock. 688 689 // Basic find on loaded classes 690 static Klass* find_class(int index, unsigned int hash, 691 Symbol* name, ClassLoaderData* loader_data); 692 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 693 694 // Basic find on classes in the midst of being loaded 695 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 696 697 // Add a placeholder for a class being loaded 698 static void add_placeholder(int index, 699 Symbol* class_name, 700 ClassLoaderData* loader_data); 701 static void remove_placeholder(int index, 702 Symbol* class_name, 703 ClassLoaderData* loader_data); 704 705 // Performs cleanups after resolve_super_or_fail. This typically needs 706 // to be called on failure. 707 // Won't throw, but can block. 708 static void resolution_cleanups(Symbol* class_name, 709 ClassLoaderData* loader_data, 710 TRAPS); 711 712 // Initialization 713 static void initialize_preloaded_classes(TRAPS); 714 715 // Class loader constraints 716 static void check_constraints(int index, unsigned int hash, 717 instanceKlassHandle k, Handle loader, 718 bool defining, TRAPS); 719 static void update_dictionary(int d_index, unsigned int d_hash, 720 int p_index, unsigned int p_hash, 721 instanceKlassHandle k, Handle loader, 722 TRAPS); 723 724 // Variables holding commonly used klasses (preloaded) 725 static InstanceKlass* _well_known_klasses[]; 726 727 // Lazily loaded klasses 728 static InstanceKlass* volatile _abstract_ownable_synchronizer_klass; 729 730 // table of box klasses (int_klass, etc.) 731 static InstanceKlass* _box_klasses[T_VOID+1]; 732 733 // table of array interface klasses (ArrayImpl.Ref, ArrayImpl.PrimI, etc.) 734 static InstanceKlass* _array_interfaces[T_VOID+1]; 735 736 static oop _java_system_loader; 737 738 static bool _has_loadClassInternal; 739 static bool _has_checkPackageAccess; 740 }; 741 742 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP