1 /* 2 * Copyright (c) 1997, 2015, 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/classFileStream.hpp" 29 #include "classfile/classLoader.hpp" 30 #include "oops/objArrayOop.hpp" 31 #include "oops/symbol.hpp" 32 #include "runtime/java.hpp" 33 #include "runtime/reflectionUtils.hpp" 34 #include "utilities/hashtable.hpp" 35 #include "utilities/hashtable.inline.hpp" 36 #include "jvmci/systemDictionary_jvmci.hpp" 37 38 39 // The system dictionary stores all loaded classes and maps: 40 // 41 // [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass* 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 with a fixed number 47 // of buckets. During loading the loader object is locked, (for the VM loader 48 // a private lock object is used). Class loading can thus be done concurrently, 49 // but only by different loaders. 50 // 51 // During loading a placeholder (name, loader) is temporarily placed in 52 // a side data structure, and is used to detect ClassCircularityErrors 53 // and to perform verification during GC. A GC can occur in the midst 54 // of class loading, as we call out to Java, have to take locks, etc. 55 // 56 // When class loading is finished, a new entry is added to the system 57 // dictionary and the place holder is removed. Note that the protection 58 // domain field of the system dictionary has not yet been filled in when 59 // the "real" system dictionary entry is created. 60 // 61 // Clients of this class who are interested in finding if a class has 62 // been completely loaded -- not classes in the process of being loaded -- 63 // can read the SystemDictionary unlocked. This is safe because 64 // - entries are only deleted at safepoints 65 // - readers cannot come to a safepoint while actively examining 66 // an entry (an entry cannot be deleted from under a reader) 67 // - entries must be fully formed before they are available to concurrent 68 // readers (we must ensure write ordering) 69 // 70 // Note that placeholders are deleted at any time, as they are removed 71 // when a class is completely loaded. Therefore, readers as well as writers 72 // of placeholders must hold the SystemDictionary_lock. 73 // 74 75 class Dictionary; 76 class PlaceholderTable; 77 class LoaderConstraintTable; 78 template <MEMFLAGS F> class HashtableBucket; 79 class ResolutionErrorTable; 80 class SymbolPropertyTable; 81 class Ticks; 82 83 // Certain classes are preloaded, such as java.lang.Object and java.lang.String. 84 // They are all "well-known", in the sense that no class loader is allowed 85 // to provide a different definition. 86 // 87 // These klasses must all have names defined in vmSymbols. 88 89 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 90 91 // Each well-known class has a short klass name (like object_klass), 92 // a vmSymbol name (like java_lang_Object), and a flag word 93 // that makes some minor distinctions, like whether the klass 94 // is preloaded, optional, release-specific, etc. 95 // The order of these definitions is significant; it is the order in which 96 // preloading is actually performed by initialize_preloaded_classes. 97 98 #define WK_KLASSES_DO(do_klass) \ 99 /* well-known classes */ \ 100 do_klass(Object_klass, java_lang_Object, Pre ) \ 101 do_klass(String_klass, java_lang_String, Pre ) \ 102 do_klass(Class_klass, java_lang_Class, Pre ) \ 103 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \ 104 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \ 105 do_klass(Serializable_klass, java_io_Serializable, Pre ) \ 106 do_klass(System_klass, java_lang_System, Pre ) \ 107 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \ 108 do_klass(Error_klass, java_lang_Error, Pre ) \ 109 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \ 110 do_klass(Exception_klass, java_lang_Exception, Pre ) \ 111 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \ 112 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \ 113 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \ 114 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \ 115 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \ 116 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \ 117 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \ 118 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \ 119 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \ 120 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \ 121 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \ 122 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \ 123 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \ 124 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \ 125 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \ 126 \ 127 /* Preload ref klasses and set reference types */ \ 128 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \ 129 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \ 130 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \ 131 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \ 132 do_klass(Cleaner_klass, sun_misc_Cleaner, Pre ) \ 133 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \ 134 \ 135 do_klass(Thread_klass, java_lang_Thread, Pre ) \ 136 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \ 137 do_klass(Properties_klass, java_util_Properties, Pre ) \ 138 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \ 139 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \ 140 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \ 141 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \ 142 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \ 143 \ 144 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 145 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 146 do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \ 147 do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Pre ) \ 148 do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Pre ) \ 149 do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \ 150 do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt ) \ 151 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt ) \ 152 do_klass(reflect_CallerSensitive_klass, sun_reflect_CallerSensitive, Opt ) \ 153 \ 154 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 155 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \ 156 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \ 157 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \ 158 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \ 159 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \ 160 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \ 161 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \ 162 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \ 163 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre ) \ 164 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \ 165 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \ 166 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \ 167 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 168 \ 169 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \ 170 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \ 171 do_klass(internal_Unsafe_klass, jdk_internal_misc_Unsafe, Pre ) \ 172 \ 173 /* support for CDS */ \ 174 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \ 175 do_klass(File_klass, java_io_File, Pre ) \ 176 do_klass(URLClassLoader_klass, java_net_URLClassLoader, Pre ) \ 177 do_klass(URL_klass, java_net_URL, Pre ) \ 178 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \ 179 do_klass(sun_misc_Launcher_klass, sun_misc_Launcher, Pre ) \ 180 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \ 181 \ 182 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 183 \ 184 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 185 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \ 186 \ 187 /* Stack Walking */ \ 188 do_klass(StackWalker_klass, java_lang_StackWalker, Opt ) \ 189 do_klass(AbstractStackWalker_klass, java_lang_StackStreamFactory_AbstractStackWalker, Opt ) \ 190 do_klass(StackFrameInfo_klass, java_lang_StackFrameInfo, Opt ) \ 191 do_klass(LiveStackFrameInfo_klass, java_lang_LiveStackFrameInfo, Opt ) \ 192 \ 193 /* Preload boxing klasses */ \ 194 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \ 195 do_klass(Character_klass, java_lang_Character, Pre ) \ 196 do_klass(Float_klass, java_lang_Float, Pre ) \ 197 do_klass(Double_klass, java_lang_Double, Pre ) \ 198 do_klass(Byte_klass, java_lang_Byte, Pre ) \ 199 do_klass(Short_klass, java_lang_Short, Pre ) \ 200 do_klass(Integer_klass, java_lang_Integer, Pre ) \ 201 do_klass(Long_klass, java_lang_Long, Pre ) \ 202 \ 203 /* JVMCI classes. These are loaded on-demand. */ \ 204 JVMCI_WK_KLASSES_DO(do_klass) \ 205 206 /*end*/ 207 208 209 class SystemDictionary : AllStatic { 210 friend class VMStructs; 211 friend class SystemDictionaryHandles; 212 213 public: 214 enum WKID { 215 NO_WKID = 0, 216 217 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 218 WK_KLASSES_DO(WK_KLASS_ENUM) 219 #undef WK_KLASS_ENUM 220 221 WKID_LIMIT, 222 223 #if INCLUDE_JVMCI 224 FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(HotSpotCompiledCode_klass), 225 LAST_JVMCI_WKID = WK_KLASS_ENUM_NAME(Value_klass), 226 #endif 227 228 FIRST_WKID = NO_WKID + 1 229 }; 230 231 enum InitOption { 232 Pre, // preloaded; error if not present 233 234 // Order is significant. Options before this point require resolve_or_fail. 235 // Options after this point will use resolve_or_null instead. 236 237 Opt, // preload tried; NULL if not present 238 #if INCLUDE_JVMCI 239 Jvmci, // preload tried; error if not present, use only with JVMCI 240 #endif 241 OPTION_LIMIT, 242 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 243 }; 244 245 246 // Returns a class with a given class name and class loader. Loads the 247 // class if needed. If not found a NoClassDefFoundError or a 248 // ClassNotFoundException is thrown, depending on the value on the 249 // throw_error flag. For most uses the throw_error argument should be set 250 // to true. 251 252 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 253 // Convenient call for null loader and protection domain. 254 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 255 protected: 256 // handle error translation for resolve_or_null results 257 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, KlassHandle klass_h, TRAPS); 258 259 public: 260 261 // Returns a class with a given class name and class loader. 262 // Loads the class if needed. If not found NULL is returned. 263 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 264 // Version with null loader and protection domain 265 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 266 267 // Resolve a superclass or superinterface. Called from ClassFileParser, 268 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 269 // "child_name" is the class whose super class or interface is being resolved. 270 static Klass* resolve_super_or_fail(Symbol* child_name, 271 Symbol* class_name, 272 Handle class_loader, 273 Handle protection_domain, 274 bool is_superclass, 275 TRAPS); 276 277 // Parse new stream. This won't update the system dictionary or 278 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 279 static Klass* parse_stream(Symbol* class_name, 280 Handle class_loader, 281 Handle protection_domain, 282 ClassFileStream* st, 283 TRAPS) { 284 KlassHandle nullHandle; 285 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD); 286 } 287 static Klass* parse_stream(Symbol* class_name, 288 Handle class_loader, 289 Handle protection_domain, 290 ClassFileStream* st, 291 KlassHandle host_klass, 292 GrowableArray<Handle>* cp_patches, 293 TRAPS); 294 295 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 296 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader, 297 Handle protection_domain, 298 ClassFileStream* st, bool verify, TRAPS); 299 300 // Lookup an already loaded class. If not found NULL is returned. 301 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 302 303 // Lookup an already loaded instance or array class. 304 // Do not make any queries to class loaders; consult only the cache. 305 // If not found NULL is returned. 306 static Klass* find_instance_or_array_klass(Symbol* class_name, 307 Handle class_loader, 308 Handle protection_domain, 309 TRAPS); 310 311 // Lookup an instance or array class that has already been loaded 312 // either into the given class loader, or else into another class 313 // loader that is constrained (via loader constraints) to produce 314 // a consistent class. Do not take protection domains into account. 315 // Do not make any queries to class loaders; consult only the cache. 316 // Return NULL if the class is not found. 317 // 318 // This function is a strict superset of find_instance_or_array_klass. 319 // This function (the unchecked version) makes a conservative prediction 320 // of the result of the checked version, assuming successful lookup. 321 // If both functions return non-null, they must return the same value. 322 // Also, the unchecked version may sometimes be non-null where the 323 // checked version is null. This can occur in several ways: 324 // 1. No query has yet been made to the class loader. 325 // 2. The class loader was queried, but chose not to delegate. 326 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 327 // 4. Loading was attempted, but there was a linkage error of some sort. 328 // In all of these cases, the loader constraints on this type are 329 // satisfied, and it is safe for classes in the given class loader 330 // to manipulate strongly-typed values of the found class, subject 331 // to local linkage and access checks. 332 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 333 Handle class_loader, 334 TRAPS); 335 336 // Iterate over all klasses in dictionary 337 // Just the classes from defining class loaders 338 static void classes_do(void f(Klass*)); 339 // Added for initialize_itable_for_klass to handle exceptions 340 static void classes_do(void f(Klass*, TRAPS), TRAPS); 341 // All classes, and their class loaders 342 static void classes_do(void f(Klass*, ClassLoaderData*)); 343 344 static void placeholders_do(void f(Symbol*)); 345 346 // Iterate over all methods in all klasses in dictionary 347 static void methods_do(void f(Method*)); 348 349 // Garbage collection support 350 351 // This method applies "blk->do_oop" to all the pointers to "system" 352 // classes and loaders. 353 static void always_strong_oops_do(OopClosure* blk); 354 static void always_strong_classes_do(KlassClosure* closure); 355 356 // Unload (that is, break root links to) all unmarked classes and 357 // loaders. Returns "true" iff something was unloaded. 358 static bool do_unloading(BoolObjectClosure* is_alive, 359 bool clean_previous_versions = true); 360 361 // Used by DumpSharedSpaces only to remove classes that failed verification 362 static void remove_classes_in_error_state(); 363 364 static int calculate_systemdictionary_size(int loadedclasses); 365 366 // Applies "f->do_oop" to all root oops in the system dictionary. 367 static void oops_do(OopClosure* f); 368 static void roots_oops_do(OopClosure* strong, OopClosure* weak); 369 370 // System loader lock 371 static oop system_loader_lock() { return _system_loader_lock_obj; } 372 373 protected: 374 // Extended Redefine classes support (tbi) 375 static void preloaded_classes_do(KlassClosure* f); 376 static void lazily_loaded_classes_do(KlassClosure* f); 377 public: 378 // Sharing support. 379 static void reorder_dictionary(); 380 static void copy_buckets(char** top, char* end); 381 static void copy_table(char** top, char* end); 382 static void reverse(); 383 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 384 int number_of_entries); 385 // Printing 386 static void print(bool details = true); 387 static void print_shared(bool details = true); 388 389 // Number of contained klasses 390 // This is both fully loaded classes and classes in the process 391 // of being loaded 392 static int number_of_classes(); 393 394 // Monotonically increasing counter which grows as classes are 395 // loaded or modifications such as hot-swapping or setting/removing 396 // of breakpoints are performed 397 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 398 // Needed by evolution and breakpoint code 399 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 400 401 // Verification 402 static void verify(); 403 404 #ifdef ASSERT 405 static bool is_internal_format(Symbol* class_name); 406 #endif 407 408 // Initialization 409 static void initialize(TRAPS); 410 411 // Fast access to commonly used classes (preloaded) 412 static InstanceKlass* check_klass(InstanceKlass* k) { 413 assert(k != NULL, "preloaded klass not initialized"); 414 return k; 415 } 416 417 static InstanceKlass* check_klass_Pre(InstanceKlass* k) { return check_klass(k); } 418 static InstanceKlass* check_klass_Opt(InstanceKlass* k) { return k; } 419 420 JVMCI_ONLY(static InstanceKlass* check_klass_Jvmci(InstanceKlass* k) { return k; }) 421 422 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 423 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 424 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 425 int limit = (int)end_id + 1; 426 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 427 } 428 429 public: 430 #define WK_KLASS_DECLARE(name, symbol, option) \ 431 static InstanceKlass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 432 static InstanceKlass** name##_addr() { \ 433 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 434 } 435 WK_KLASSES_DO(WK_KLASS_DECLARE); 436 #undef WK_KLASS_DECLARE 437 438 static InstanceKlass* well_known_klass(WKID id) { 439 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 440 return _well_known_klasses[id]; 441 } 442 443 static InstanceKlass** well_known_klass_addr(WKID id) { 444 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 445 return &_well_known_klasses[id]; 446 } 447 448 // Local definition for direct access to the private array: 449 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 450 451 static InstanceKlass* box_klass(BasicType t) { 452 assert((uint)t < T_VOID+1, "range check"); 453 return check_klass(_box_klasses[t]); 454 } 455 static BasicType box_klass_type(Klass* k); // inverse of box_klass 456 457 // methods returning lazily loaded klasses 458 // The corresponding method to load the class must be called before calling them. 459 static InstanceKlass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 460 461 static void load_abstract_ownable_synchronizer_klass(TRAPS); 462 463 protected: 464 // Tells whether ClassLoader.loadClassInternal is present 465 static bool has_loadClassInternal() { return _has_loadClassInternal; } 466 467 // Returns the class loader data to be used when looking up/updating the 468 // system dictionary. 469 static ClassLoaderData *class_loader_data(Handle class_loader) { 470 return ClassLoaderData::class_loader_data(class_loader()); 471 } 472 473 public: 474 // Tells whether ClassLoader.checkPackageAccess is present 475 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 476 477 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 478 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 479 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 480 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 481 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 482 483 // Returns default system loader 484 static oop java_system_loader(); 485 486 // Compute the default system loader 487 static void compute_java_system_loader(TRAPS); 488 489 // Register a new class loader 490 static ClassLoaderData* register_loader(Handle class_loader, TRAPS); 491 protected: 492 // Mirrors for primitive classes (created eagerly) 493 static oop check_mirror(oop m) { 494 assert(m != NULL, "mirror not initialized"); 495 return m; 496 } 497 498 public: 499 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 500 501 // Check class loader constraints 502 static bool add_loader_constraint(Symbol* name, Handle loader1, 503 Handle loader2, TRAPS); 504 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 505 Handle loader2, bool is_method, TRAPS); 506 507 // JSR 292 508 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 509 // (asks Java to compute it if necessary, except in a compiler thread) 510 static methodHandle find_method_handle_invoker(Symbol* name, 511 Symbol* signature, 512 KlassHandle accessing_klass, 513 Handle *appendix_result, 514 Handle *method_type_result, 515 TRAPS); 516 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 517 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 518 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 519 Symbol* signature, 520 TRAPS); 521 // find a java.lang.invoke.MethodType object for a given signature 522 // (asks Java to compute it if necessary, except in a compiler thread) 523 static Handle find_method_handle_type(Symbol* signature, 524 KlassHandle accessing_klass, 525 TRAPS); 526 527 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 528 static Handle link_method_handle_constant(KlassHandle caller, 529 int ref_kind, //e.g., JVM_REF_invokeVirtual 530 KlassHandle callee, 531 Symbol* name, 532 Symbol* signature, 533 TRAPS); 534 535 // ask Java to create a dynamic call site, while linking an invokedynamic op 536 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller, 537 Handle bootstrap_method, 538 Symbol* name, 539 Symbol* type, 540 Handle *appendix_result, 541 Handle *method_type_result, 542 TRAPS); 543 544 // Utility for printing loader "name" as part of tracing constraints 545 static const char* loader_name(oop loader) { 546 return ((loader) == NULL ? "<bootloader>" : 547 InstanceKlass::cast((loader)->klass())->name()->as_C_string() ); 548 } 549 static const char* loader_name(ClassLoaderData* loader_data) { 550 return (loader_data->class_loader() == NULL ? "<bootloader>" : 551 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() ); 552 } 553 554 // Record the error when the first attempt to resolve a reference from a constant 555 // pool entry to a class fails. 556 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error, 557 Symbol* message); 558 static void delete_resolution_error(ConstantPool* pool); 559 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which, 560 Symbol** message); 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 _nof_buckets = 1009, // number of buckets in hash table for placeholders 569 _old_default_sdsize = 1009, // backward compat for system dictionary size 570 _prime_array_size = 8, // array of primes for system dictionary size 571 _average_depth_goal = 3 // goal for lookup length 572 }; 573 574 575 // Static variables 576 577 // hashtable sizes for system dictionary to allow growth 578 // prime numbers for system dictionary size 579 static int _sdgeneration; 580 static const int _primelist[_prime_array_size]; 581 582 // Hashtable holding loaded classes. 583 static Dictionary* _dictionary; 584 585 // Hashtable holding placeholders for classes being loaded. 586 static PlaceholderTable* _placeholders; 587 588 // Hashtable holding classes from the shared archive. 589 static Dictionary* _shared_dictionary; 590 591 // Monotonically increasing counter which grows with 592 // _number_of_classes as well as hot-swapping and breakpoint setting 593 // and removal. 594 static int _number_of_modifications; 595 596 // Lock object for system class loader 597 static oop _system_loader_lock_obj; 598 599 // Constraints on class loaders 600 static LoaderConstraintTable* _loader_constraints; 601 602 // Resolution errors 603 static ResolutionErrorTable* _resolution_errors; 604 605 // Invoke methods (JSR 292) 606 static SymbolPropertyTable* _invoke_method_table; 607 608 public: 609 // for VM_CounterDecay iteration support 610 friend class CounterDecay; 611 static Klass* try_get_next_class(); 612 613 protected: 614 static void validate_protection_domain(instanceKlassHandle klass, 615 Handle class_loader, 616 Handle protection_domain, TRAPS); 617 618 friend class VM_PopulateDumpSharedSpace; 619 friend class TraversePlaceholdersClosure; 620 static Dictionary* dictionary() { return _dictionary; } 621 static Dictionary* shared_dictionary() { return _shared_dictionary; } 622 static PlaceholderTable* placeholders() { return _placeholders; } 623 static LoaderConstraintTable* constraints() { return _loader_constraints; } 624 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 625 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 626 627 // Basic loading operations 628 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 629 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 630 static instanceKlassHandle 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(instanceKlassHandle k, TRAPS); 637 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name, 638 Handle class_loader, 639 instanceKlassHandle k, TRAPS); 640 static instanceKlassHandle load_shared_class(instanceKlassHandle ik, 641 Handle class_loader, 642 Handle protection_domain, 643 TRAPS); 644 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 645 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 646 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 647 static bool is_parallelCapable(Handle class_loader); 648 static bool is_parallelDefine(Handle class_loader); 649 650 public: 651 static instanceKlassHandle load_shared_class(Symbol* class_name, 652 Handle class_loader, 653 TRAPS); 654 static bool is_ext_class_loader(Handle class_loader); 655 656 protected: 657 static Klass* find_shared_class(Symbol* class_name); 658 659 // Setup link to hierarchy 660 static void add_to_hierarchy(instanceKlassHandle k, TRAPS); 661 662 // event based tracing 663 static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k, 664 Handle initiating_loader); 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 Klass* find_class(int index, unsigned int hash, 670 Symbol* name, ClassLoaderData* loader_data); 671 static Klass* 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 // Updating entry in dictionary 677 // Add a completely loaded class 678 static void add_klass(int index, Symbol* class_name, 679 ClassLoaderData* loader_data, KlassHandle obj); 680 681 // Add a placeholder for a class being loaded 682 static void add_placeholder(int index, 683 Symbol* class_name, 684 ClassLoaderData* loader_data); 685 static void remove_placeholder(int index, 686 Symbol* class_name, 687 ClassLoaderData* loader_data); 688 689 // Performs cleanups after resolve_super_or_fail. This typically needs 690 // to be called on failure. 691 // Won't throw, but can block. 692 static void resolution_cleanups(Symbol* class_name, 693 ClassLoaderData* loader_data, 694 TRAPS); 695 696 // Initialization 697 static void initialize_preloaded_classes(TRAPS); 698 699 // Class loader constraints 700 static void check_constraints(int index, unsigned int hash, 701 instanceKlassHandle k, Handle loader, 702 bool defining, TRAPS); 703 static void update_dictionary(int d_index, unsigned int d_hash, 704 int p_index, unsigned int p_hash, 705 instanceKlassHandle k, Handle loader, 706 TRAPS); 707 708 // Variables holding commonly used klasses (preloaded) 709 static InstanceKlass* _well_known_klasses[]; 710 711 // Lazily loaded klasses 712 static InstanceKlass* volatile _abstract_ownable_synchronizer_klass; 713 714 // table of box klasses (int_klass, etc.) 715 static InstanceKlass* _box_klasses[T_VOID+1]; 716 717 static oop _java_system_loader; 718 719 static bool _has_loadClassInternal; 720 static bool _has_checkPackageAccess; 721 }; 722 723 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP