1 /* 2 * Copyright (c) 1997, 2017, 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 dictionary in each ClassLoaderData stores all loaded classes, either 39 // initiatied by its class loader or defined by its class loader: 40 // 41 // class loader -> ClassLoaderData -> [class, protection domain set] 42 // 43 // Classes are loaded lazily. The default VM class loader is 44 // represented as NULL. 45 46 // The underlying data structure is an open hash table (Dictionary) per 47 // ClassLoaderData with a fixed number of buckets. During loading the 48 // class loader object is locked, (for the VM loader a private lock object is used). 49 // The global SystemDictionary_lock is held for all additions into the ClassLoaderData 50 // dictionaries. TODO: fix lock granularity so that class loading can 51 // be done concurrently, but only by different loaders. 52 // 53 // During loading a placeholder (name, loader) is temporarily placed in 54 // a side data structure, and is used to detect ClassCircularityErrors 55 // and to perform verification during GC. A GC can occur in the midst 56 // of class loading, as we call out to Java, have to take locks, etc. 57 // 58 // When class loading is finished, a new entry is added to the dictionary 59 // of the class loader and the placeholder is removed. Note that the protection 60 // domain field of the dictionary entry has not yet been filled in when 61 // the "real" dictionary entry is created. 62 // 63 // Clients of this class who are interested in finding if a class has 64 // been completely loaded -- not classes in the process of being loaded -- 65 // can read the dictionary unlocked. This is safe because 66 // - entries are only deleted at safepoints 67 // - readers cannot come to a safepoint while actively examining 68 // an entry (an entry cannot be deleted from under a reader) 69 // - entries must be fully formed before they are available to concurrent 70 // readers (we must ensure write ordering) 71 // 72 // Note that placeholders are deleted at any time, as they are removed 73 // when a class is completely loaded. Therefore, readers as well as writers 74 // of placeholders must hold the SystemDictionary_lock. 75 // 76 77 class ClassFileStream; 78 class Dictionary; 79 class PlaceholderTable; 80 class LoaderConstraintTable; 81 template <MEMFLAGS F> class HashtableBucket; 82 class ResolutionErrorTable; 83 class SymbolPropertyTable; 84 class ProtectionDomainCacheTable; 85 class ProtectionDomainCacheEntry; 86 class GCTimer; 87 88 // Certain classes are preloaded, such as java.lang.Object and java.lang.String. 89 // They are all "well-known", in the sense that no class loader is allowed 90 // to provide a different definition. 91 // 92 // These klasses must all have names defined in vmSymbols. 93 94 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 95 96 // Each well-known class has a short klass name (like object_klass), 97 // a vmSymbol name (like java_lang_Object), and a flag word 98 // that makes some minor distinctions, like whether the klass 99 // is preloaded, optional, release-specific, etc. 100 // The order of these definitions is significant; it is the order in which 101 // preloading is actually performed by initialize_preloaded_classes. 102 103 #define WK_KLASSES_DO(do_klass) \ 104 /* well-known classes */ \ 105 do_klass(Object_klass, java_lang_Object, Pre ) \ 106 do_klass(String_klass, java_lang_String, Pre ) \ 107 do_klass(Class_klass, java_lang_Class, Pre ) \ 108 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \ 109 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \ 110 do_klass(Serializable_klass, java_io_Serializable, Pre ) \ 111 do_klass(System_klass, java_lang_System, Pre ) \ 112 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \ 113 do_klass(Error_klass, java_lang_Error, Pre ) \ 114 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \ 115 do_klass(Exception_klass, java_lang_Exception, Pre ) \ 116 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \ 117 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \ 118 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \ 119 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \ 120 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \ 121 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \ 122 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \ 123 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \ 124 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \ 125 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \ 126 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \ 127 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \ 128 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \ 129 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \ 130 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \ 131 \ 132 /* Preload ref klasses and set reference types */ \ 133 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \ 134 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \ 135 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \ 136 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \ 137 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \ 138 \ 139 do_klass(Thread_klass, java_lang_Thread, Pre ) \ 140 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \ 141 do_klass(Properties_klass, java_util_Properties, Pre ) \ 142 do_klass(Module_klass, java_lang_Module, Pre ) \ 143 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \ 144 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \ 145 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \ 146 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \ 147 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \ 148 \ 149 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 150 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 151 do_klass(reflect_MagicAccessorImpl_klass, reflect_MagicAccessorImpl, Opt ) \ 152 do_klass(reflect_MethodAccessorImpl_klass, reflect_MethodAccessorImpl, Pre ) \ 153 do_klass(reflect_ConstructorAccessorImpl_klass, reflect_ConstructorAccessorImpl, Pre ) \ 154 do_klass(reflect_DelegatingClassLoader_klass, reflect_DelegatingClassLoader, Opt ) \ 155 do_klass(reflect_ConstantPool_klass, reflect_ConstantPool, Opt ) \ 156 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, reflect_UnsafeStaticFieldAccessorImpl, Opt ) \ 157 do_klass(reflect_CallerSensitive_klass, reflect_CallerSensitive, Opt ) \ 158 \ 159 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 160 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \ 161 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \ 162 do_klass(VarHandle_klass, java_lang_invoke_VarHandle, Pre ) \ 163 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \ 164 do_klass(ResolvedMethodName_klass, java_lang_invoke_ResolvedMethodName, Pre ) \ 165 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \ 166 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \ 167 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \ 168 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \ 169 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \ 170 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre ) \ 171 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \ 172 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \ 173 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \ 174 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 175 \ 176 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \ 177 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \ 178 do_klass(internal_Unsafe_klass, jdk_internal_misc_Unsafe, Pre ) \ 179 do_klass(module_Modules_klass, jdk_internal_module_Modules, Pre ) \ 180 \ 181 /* support for CDS */ \ 182 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \ 183 do_klass(File_klass, java_io_File, Pre ) \ 184 do_klass(URL_klass, java_net_URL, Pre ) \ 185 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \ 186 do_klass(jdk_internal_loader_ClassLoaders_AppClassLoader_klass, jdk_internal_loader_ClassLoaders_AppClassLoader, Pre ) \ 187 do_klass(jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass, jdk_internal_loader_ClassLoaders_PlatformClassLoader, Pre ) \ 188 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \ 189 do_klass(ParseUtil_klass, sun_net_www_ParseUtil, Pre ) \ 190 \ 191 /* support for valhalla "shady" value type bytecode transformer */ \ 192 do_klass(ValueCapableClass_klass, jvm_internal_value_ValueCapableClass, MVTClasses ) \ 193 do_klass(Valhalla_MVT1_0_klass, valhalla_shady_MVT1_0, MVTClasses ) \ 194 \ 195 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 196 \ 197 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 198 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \ 199 \ 200 /* Stack Walking */ \ 201 do_klass(StackWalker_klass, java_lang_StackWalker, Opt ) \ 202 do_klass(AbstractStackWalker_klass, java_lang_StackStreamFactory_AbstractStackWalker, Opt ) \ 203 do_klass(StackFrameInfo_klass, java_lang_StackFrameInfo, Opt ) \ 204 do_klass(LiveStackFrameInfo_klass, java_lang_LiveStackFrameInfo, Opt ) \ 205 \ 206 /* Preload boxing klasses */ \ 207 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \ 208 do_klass(Character_klass, java_lang_Character, Pre ) \ 209 do_klass(Float_klass, java_lang_Float, Pre ) \ 210 do_klass(Double_klass, java_lang_Double, Pre ) \ 211 do_klass(Byte_klass, java_lang_Byte, Pre ) \ 212 do_klass(Short_klass, java_lang_Short, Pre ) \ 213 do_klass(Integer_klass, java_lang_Integer, Pre ) \ 214 do_klass(Long_klass, java_lang_Long, Pre ) \ 215 \ 216 do_klass(___Value_klass, java_lang____Value, ValhallaClasses ) \ 217 \ 218 /* Extensions */ \ 219 WK_KLASSES_DO_EXT(do_klass) \ 220 /* JVMCI classes. These are loaded on-demand. */ \ 221 JVMCI_WK_KLASSES_DO(do_klass) \ 222 \ 223 /*end*/ 224 225 226 class SystemDictionary : AllStatic { 227 friend class VMStructs; 228 friend class SystemDictionaryHandles; 229 friend class SharedClassUtil; 230 231 public: 232 enum WKID { 233 NO_WKID = 0, 234 235 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 236 WK_KLASSES_DO(WK_KLASS_ENUM) 237 #undef WK_KLASS_ENUM 238 239 WKID_LIMIT, 240 241 #if INCLUDE_JVMCI 242 FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(JVMCI_klass), 243 LAST_JVMCI_WKID = WK_KLASS_ENUM_NAME(Value_klass), 244 #endif 245 246 FIRST_WKID = NO_WKID + 1 247 }; 248 249 enum InitOption { 250 Pre, // preloaded; error if not present 251 252 // Order is significant. Options before this point require resolve_or_fail. 253 // Options after this point will use resolve_or_null instead. 254 255 Opt, // preload tried; NULL if not present 256 #if INCLUDE_JVMCI 257 Jvmci, // preload tried; error if not present if JVMCI enabled 258 #endif 259 ValhallaClasses, // loaded if Valhalla enabled 260 MVTClasses, // loaded if MVT enabled 261 OPTION_LIMIT, 262 CEIL_LG_OPTION_LIMIT = 3 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 263 }; 264 265 266 // Returns a class with a given class name and class loader. Loads the 267 // class if needed. If not found a NoClassDefFoundError or a 268 // ClassNotFoundException is thrown, depending on the value on the 269 // throw_error flag. For most uses the throw_error argument should be set 270 // to true. 271 272 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 273 // Convenient call for null loader and protection domain. 274 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 275 protected: 276 // handle error translation for resolve_or_null results 277 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, Klass* klass, TRAPS); 278 279 public: 280 281 // Returns a class with a given class name and class loader. 282 // Loads the class if needed. If not found NULL is returned. 283 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 284 // Version with null loader and protection domain 285 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 286 287 // Resolve a superclass or superinterface. Called from ClassFileParser, 288 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 289 // "child_name" is the class whose super class or interface is being resolved. 290 static Klass* resolve_super_or_fail(Symbol* child_name, 291 Symbol* class_name, 292 Handle class_loader, 293 Handle protection_domain, 294 bool is_superclass, 295 TRAPS); 296 297 // Parse new stream. This won't update the dictionary or 298 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 299 // Also used by Unsafe_DefineAnonymousClass 300 static InstanceKlass* parse_stream(Symbol* class_name, 301 Handle class_loader, 302 Handle protection_domain, 303 ClassFileStream* st, 304 TRAPS) { 305 return parse_stream(class_name, 306 class_loader, 307 protection_domain, 308 st, 309 NULL, // host klass 310 NULL, // cp_patches 311 THREAD); 312 } 313 static InstanceKlass* parse_stream(Symbol* class_name, 314 Handle class_loader, 315 Handle protection_domain, 316 ClassFileStream* st, 317 const InstanceKlass* host_klass, 318 GrowableArray<Handle>* cp_patches, 319 TRAPS); 320 321 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 322 static InstanceKlass* resolve_from_stream(Symbol* class_name, 323 Handle class_loader, 324 Handle protection_domain, 325 ClassFileStream* st, 326 TRAPS); 327 328 // Lookup an already loaded class. If not found NULL is returned. 329 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 330 331 // Lookup an already loaded instance or array class. 332 // Do not make any queries to class loaders; consult only the cache. 333 // If not found NULL is returned. 334 static Klass* find_instance_or_array_klass(Symbol* class_name, 335 Handle class_loader, 336 Handle protection_domain, 337 TRAPS); 338 339 // Lookup an instance or array class that has already been loaded 340 // either into the given class loader, or else into another class 341 // loader that is constrained (via loader constraints) to produce 342 // a consistent class. Do not take protection domains into account. 343 // Do not make any queries to class loaders; consult only the cache. 344 // Return NULL if the class is not found. 345 // 346 // This function is a strict superset of find_instance_or_array_klass. 347 // This function (the unchecked version) makes a conservative prediction 348 // of the result of the checked version, assuming successful lookup. 349 // If both functions return non-null, they must return the same value. 350 // Also, the unchecked version may sometimes be non-null where the 351 // checked version is null. This can occur in several ways: 352 // 1. No query has yet been made to the class loader. 353 // 2. The class loader was queried, but chose not to delegate. 354 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 355 // 4. Loading was attempted, but there was a linkage error of some sort. 356 // In all of these cases, the loader constraints on this type are 357 // satisfied, and it is safe for classes in the given class loader 358 // to manipulate strongly-typed values of the found class, subject 359 // to local linkage and access checks. 360 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 361 Handle class_loader, 362 TRAPS); 363 364 static void classes_do(MetaspaceClosure* it); 365 // Iterate over all methods in all klasses 366 367 static void methods_do(void f(Method*)); 368 369 // Garbage collection support 370 371 // This method applies "blk->do_oop" to all the pointers to "system" 372 // classes and loaders. 373 static void always_strong_oops_do(OopClosure* blk); 374 375 // Unload (that is, break root links to) all unmarked classes and 376 // loaders. Returns "true" iff something was unloaded. 377 static bool do_unloading(BoolObjectClosure* is_alive, 378 GCTimer* gc_timer, 379 bool do_cleaning = true); 380 381 // Used by DumpSharedSpaces only to remove classes that failed verification 382 static void remove_classes_in_error_state(); 383 384 static int calculate_systemdictionary_size(int loadedclasses); 385 386 // Applies "f->do_oop" to all root oops in the system dictionary. 387 static void oops_do(OopClosure* f); 388 static void roots_oops_do(OopClosure* strong, OopClosure* weak); 389 390 // System loader lock 391 static oop system_loader_lock() { return _system_loader_lock_obj; } 392 393 public: 394 // Sharing support. 395 static void reorder_dictionary_for_sharing(); 396 static size_t count_bytes_for_buckets(); 397 static size_t count_bytes_for_table(); 398 static void copy_buckets(char* top, char* end); 399 static void copy_table(char* top, char* end); 400 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 401 int number_of_entries); 402 // Printing 403 static void print() { return print_on(tty); } 404 static void print_on(outputStream* st); 405 static void print_shared(outputStream* st); 406 static void dump(outputStream* st, bool verbose); 407 408 // Monotonically increasing counter which grows as classes are 409 // loaded or modifications such as hot-swapping or setting/removing 410 // of breakpoints are performed 411 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 412 // Needed by evolution and breakpoint code 413 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 414 415 // Verification 416 static void verify(); 417 418 // Initialization 419 static void initialize(TRAPS); 420 421 // Checked fast access to commonly used classes - mostly preloaded 422 static InstanceKlass* check_klass(InstanceKlass* k) { 423 assert(k != NULL, "klass not loaded"); 424 return k; 425 } 426 427 static InstanceKlass* check_klass_Pre(InstanceKlass* k) { return check_klass(k); } 428 static InstanceKlass* check_klass_Opt(InstanceKlass* k) { return k; } 429 static InstanceKlass* check_klass_ValhallaClasses(InstanceKlass* k) { return k; } 430 static InstanceKlass* check_klass_MVTClasses(InstanceKlass* k) { return k; } 431 432 JVMCI_ONLY(static InstanceKlass* check_klass_Jvmci(InstanceKlass* k) { return k; }) 433 434 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 435 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 436 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 437 int limit = (int)end_id + 1; 438 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 439 } 440 441 public: 442 #define WK_KLASS_DECLARE(name, symbol, option) \ 443 static InstanceKlass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 444 static InstanceKlass** name##_addr() { \ 445 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 446 } 447 WK_KLASSES_DO(WK_KLASS_DECLARE); 448 #undef WK_KLASS_DECLARE 449 450 static InstanceKlass* well_known_klass(WKID id) { 451 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 452 return _well_known_klasses[id]; 453 } 454 455 static InstanceKlass** well_known_klass_addr(WKID id) { 456 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 457 return &_well_known_klasses[id]; 458 } 459 static void well_known_klasses_do(MetaspaceClosure* it); 460 461 // Local definition for direct access to the private array: 462 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 463 464 static InstanceKlass* box_klass(BasicType t) { 465 assert((uint)t < T_VOID+1, "range check"); 466 return check_klass(_box_klasses[t]); 467 } 468 static BasicType box_klass_type(Klass* k); // inverse of box_klass 469 470 // methods returning lazily loaded klasses 471 // The corresponding method to load the class must be called before calling them. 472 static InstanceKlass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 473 474 static void load_abstract_ownable_synchronizer_klass(TRAPS); 475 476 protected: 477 // Tells whether ClassLoader.loadClassInternal is present 478 static bool has_loadClassInternal() { return _has_loadClassInternal; } 479 480 // Returns the class loader data to be used when looking up/updating the 481 // system dictionary. 482 static ClassLoaderData *class_loader_data(Handle class_loader) { 483 return ClassLoaderData::class_loader_data(class_loader()); 484 } 485 486 public: 487 // Tells whether ClassLoader.checkPackageAccess is present 488 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 489 490 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 491 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 492 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 493 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 494 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 495 496 // Returns default system loader 497 static oop java_system_loader(); 498 499 // Compute the default system loader 500 static void compute_java_system_loader(TRAPS); 501 502 // Register a new class loader 503 static ClassLoaderData* register_loader(Handle class_loader, TRAPS); 504 protected: 505 // Mirrors for primitive classes (created eagerly) 506 static oop check_mirror(oop m) { 507 assert(m != NULL, "mirror not initialized"); 508 return m; 509 } 510 511 public: 512 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 513 514 // Check class loader constraints 515 static bool add_loader_constraint(Symbol* name, Handle loader1, 516 Handle loader2, TRAPS); 517 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 518 Handle loader2, bool is_method, TRAPS); 519 520 // JSR 292 521 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 522 // (asks Java to compute it if necessary, except in a compiler thread) 523 static methodHandle find_method_handle_invoker(Klass* klass, 524 Symbol* name, 525 Symbol* signature, 526 Klass* accessing_klass, 527 Handle *appendix_result, 528 Handle *method_type_result, 529 TRAPS); 530 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 531 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 532 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 533 Symbol* signature, 534 TRAPS); 535 // find a java.lang.invoke.MethodType object for a given signature 536 // (asks Java to compute it if necessary, except in a compiler thread) 537 static Handle find_method_handle_type(Symbol* signature, 538 Klass* accessing_klass, 539 TRAPS); 540 541 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 542 static Handle link_method_handle_constant(Klass* caller, 543 int ref_kind, //e.g., JVM_REF_invokeVirtual 544 Klass* callee, 545 Symbol* name, 546 Symbol* signature, 547 TRAPS); 548 549 // ask Java to create a dynamic call site, while linking an invokedynamic op 550 static methodHandle find_dynamic_call_site_invoker(Klass* caller, 551 Handle bootstrap_method, 552 Symbol* name, 553 Symbol* type, 554 Handle *appendix_result, 555 Handle *method_type_result, 556 TRAPS); 557 558 // Utility for printing loader "name" as part of tracing constraints 559 static const char* loader_name(const oop loader); 560 static const char* loader_name(const ClassLoaderData* loader_data); 561 562 // Record the error when the first attempt to resolve a reference from a constant 563 // pool entry to a class fails. 564 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error, 565 Symbol* message); 566 static void delete_resolution_error(ConstantPool* pool); 567 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which, 568 Symbol** message); 569 570 571 static ProtectionDomainCacheEntry* cache_get(Handle protection_domain); 572 573 protected: 574 575 enum Constants { 576 _loader_constraint_size = 107, // number of entries in constraint table 577 _resolution_error_size = 107, // number of entries in resolution error table 578 _invoke_method_size = 139, // number of entries in invoke method table 579 _shared_dictionary_size = 1009, // number of entries in shared dictionary 580 _placeholder_table_size = 1009 // number of entries in hash table for placeholders 581 }; 582 583 584 // Static tables owned by the SystemDictionary 585 586 // Hashtable holding placeholders for classes being loaded. 587 static PlaceholderTable* _placeholders; 588 589 // Hashtable holding classes from the shared archive. 590 static Dictionary* _shared_dictionary; 591 592 // Monotonically increasing counter which grows with 593 // loading classes as well as hot-swapping and breakpoint setting 594 // and removal. 595 static int _number_of_modifications; 596 597 // Lock object for system class loader 598 static oop _system_loader_lock_obj; 599 600 // Constraints on class loaders 601 static LoaderConstraintTable* _loader_constraints; 602 603 // Resolution errors 604 static ResolutionErrorTable* _resolution_errors; 605 606 // Invoke methods (JSR 292) 607 static SymbolPropertyTable* _invoke_method_table; 608 609 // ProtectionDomain cache 610 static ProtectionDomainCacheTable* _pd_cache_table; 611 612 protected: 613 static void validate_protection_domain(InstanceKlass* klass, 614 Handle class_loader, 615 Handle protection_domain, TRAPS); 616 617 friend class VM_PopulateDumpSharedSpace; 618 friend class TraversePlaceholdersClosure; 619 static Dictionary* shared_dictionary() { return _shared_dictionary; } 620 static PlaceholderTable* placeholders() { return _placeholders; } 621 static LoaderConstraintTable* constraints() { return _loader_constraints; } 622 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 623 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 624 625 // Basic loading operations 626 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 627 static Klass* do_resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 628 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 629 static Klass* resolve_dvt_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 630 static InstanceKlass* handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 631 // Wait on SystemDictionary_lock; unlocks lockObject before 632 // waiting; relocks lockObject with correct recursion count 633 // after waiting, but before reentering SystemDictionary_lock 634 // to preserve lock order semantics. 635 static void double_lock_wait(Handle lockObject, TRAPS); 636 static void define_instance_class(InstanceKlass* k, TRAPS); 637 static InstanceKlass* find_or_define_instance_class(Symbol* class_name, 638 Handle class_loader, 639 InstanceKlass* k, TRAPS); 640 static bool is_shared_class_visible(Symbol* class_name, InstanceKlass* ik, 641 Handle class_loader, TRAPS); 642 static InstanceKlass* load_shared_class(InstanceKlass* ik, 643 Handle class_loader, 644 Handle protection_domain, 645 TRAPS); 646 static InstanceKlass* load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 647 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 648 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 649 static bool is_parallelCapable(Handle class_loader); 650 static bool is_parallelDefine(Handle class_loader); 651 652 public: 653 static InstanceKlass* load_shared_class(Symbol* class_name, 654 Handle class_loader, 655 TRAPS); 656 static bool is_system_class_loader(oop class_loader); 657 static bool is_platform_class_loader(oop class_loader); 658 659 protected: 660 static InstanceKlass* find_shared_class(Symbol* class_name); 661 662 // Setup link to hierarchy 663 static void add_to_hierarchy(InstanceKlass* k, TRAPS); 664 665 // We pass in the hashtable index so we can calculate it outside of 666 // the SystemDictionary_lock. 667 668 // Basic find on loaded classes 669 static InstanceKlass* find_class(int index, unsigned int hash, 670 Symbol* name, Dictionary* dictionary); 671 static InstanceKlass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 672 673 // Basic find on classes in the midst of being loaded 674 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 675 676 // Add a placeholder for a class being loaded 677 static void add_placeholder(int index, 678 Symbol* class_name, 679 ClassLoaderData* loader_data); 680 static void remove_placeholder(int index, 681 Symbol* class_name, 682 ClassLoaderData* loader_data); 683 684 // Performs cleanups after resolve_super_or_fail. This typically needs 685 // to be called on failure. 686 // Won't throw, but can block. 687 static void resolution_cleanups(Symbol* class_name, 688 ClassLoaderData* loader_data, 689 TRAPS); 690 691 // Initialization 692 static void initialize_preloaded_classes(TRAPS); 693 694 // Class loader constraints 695 static void check_constraints(int index, unsigned int hash, 696 InstanceKlass* k, Handle loader, 697 bool defining, TRAPS); 698 static void update_dictionary(int d_index, unsigned int d_hash, 699 int p_index, unsigned int p_hash, 700 InstanceKlass* k, Handle loader, 701 TRAPS); 702 703 // Variables holding commonly used klasses (preloaded) 704 static InstanceKlass* _well_known_klasses[]; 705 706 // Lazily loaded klasses 707 static InstanceKlass* volatile _abstract_ownable_synchronizer_klass; 708 709 // table of box klasses (int_klass, etc.) 710 static InstanceKlass* _box_klasses[T_VOID+1]; 711 712 static oop _java_system_loader; 713 714 static bool _has_loadClassInternal; 715 static bool _has_checkPackageAccess; 716 }; 717 718 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP