1 /* 2 * Copyright (c) 1997, 2014, 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 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 Dictionary; 75 class PlaceholderTable; 76 class LoaderConstraintTable; 77 template <MEMFLAGS F> class HashtableBucket; 78 class ResolutionErrorTable; 79 class SymbolPropertyTable; 80 class Ticks; 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 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \ 144 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 145 do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \ 146 do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Opt_Only_JDK14NewRef) \ 147 do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Opt_Only_JDK14NewRef) \ 148 do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \ 149 do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt_Only_JDK15 ) \ 150 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15 ) \ 151 do_klass(reflect_CallerSensitive_klass, sun_reflect_CallerSensitive, Opt ) \ 152 \ 153 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 154 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \ 155 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre_JSR292 ) \ 156 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre_JSR292 ) \ 157 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre_JSR292 ) \ 158 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \ 159 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre_JSR292 ) \ 160 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre_JSR292 ) \ 161 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre_JSR292 ) \ 162 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre_JSR292 ) \ 163 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre_JSR292 ) \ 164 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre_JSR292 ) \ 165 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 166 \ 167 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \ 168 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \ 169 do_klass(misc_Unsafe_klass, sun_misc_Unsafe, Pre ) \ 170 \ 171 /* support for CDS */ \ 172 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \ 173 do_klass(File_klass, java_io_File, Pre ) \ 174 do_klass(URLClassLoader_klass, java_net_URLClassLoader, Pre ) \ 175 do_klass(URL_klass, java_net_URL, Pre ) \ 176 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \ 177 do_klass(sun_misc_Launcher_klass, sun_misc_Launcher, Pre ) \ 178 do_klass(sun_misc_Launcher_AppClassLoader_klass, sun_misc_Launcher_AppClassLoader, Pre ) \ 179 do_klass(sun_misc_Launcher_ExtClassLoader_klass, sun_misc_Launcher_ExtClassLoader, Pre ) \ 180 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \ 181 \ 182 /* It's NULL in non-1.4 JDKs. */ \ 183 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 184 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \ 185 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 186 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \ 187 \ 188 /* Preload boxing klasses */ \ 189 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \ 190 do_klass(Character_klass, java_lang_Character, Pre ) \ 191 do_klass(Float_klass, java_lang_Float, Pre ) \ 192 do_klass(Double_klass, java_lang_Double, Pre ) \ 193 do_klass(Byte_klass, java_lang_Byte, Pre ) \ 194 do_klass(Short_klass, java_lang_Short, Pre ) \ 195 do_klass(Integer_klass, java_lang_Integer, Pre ) \ 196 do_klass(Long_klass, java_lang_Long, Pre ) \ 197 /*end*/ 198 199 200 class SystemDictionary : AllStatic { 201 friend class VMStructs; 202 friend class SystemDictionaryHandles; 203 204 public: 205 enum WKID { 206 NO_WKID = 0, 207 208 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 209 WK_KLASSES_DO(WK_KLASS_ENUM) 210 #undef WK_KLASS_ENUM 211 212 WKID_LIMIT, 213 214 FIRST_WKID = NO_WKID + 1 215 }; 216 217 enum InitOption { 218 Pre, // preloaded; error if not present 219 Pre_JSR292, // preloaded if EnableInvokeDynamic 220 221 // Order is significant. Options before this point require resolve_or_fail. 222 // Options after this point will use resolve_or_null instead. 223 224 Opt, // preload tried; NULL if not present 225 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection 226 Opt_Only_JDK15, // preload tried; use only with JDK1.5+ 227 OPTION_LIMIT, 228 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 229 }; 230 231 232 // Returns a class with a given class name and class loader. Loads the 233 // class if needed. If not found a NoClassDefFoundError or a 234 // ClassNotFoundException is thrown, depending on the value on the 235 // throw_error flag. For most uses the throw_error argument should be set 236 // to true. 237 238 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 239 // Convenient call for null loader and protection domain. 240 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 241 protected: 242 // handle error translation for resolve_or_null results 243 static Klass* handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS); 244 245 public: 246 247 // Returns a class with a given class name and class loader. 248 // Loads the class if needed. If not found NULL is returned. 249 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 250 // Version with null loader and protection domain 251 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 252 253 // Resolve a superclass or superinterface. Called from ClassFileParser, 254 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 255 // "child_name" is the class whose super class or interface is being resolved. 256 static Klass* resolve_super_or_fail(Symbol* child_name, 257 Symbol* class_name, 258 Handle class_loader, 259 Handle protection_domain, 260 bool is_superclass, 261 TRAPS); 262 263 // Parse new stream. This won't update the system dictionary or 264 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 265 static Klass* parse_stream(Symbol* class_name, 266 Handle class_loader, 267 Handle protection_domain, 268 ClassFileStream* st, 269 TRAPS) { 270 KlassHandle nullHandle; 271 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD); 272 } 273 static Klass* parse_stream(Symbol* class_name, 274 Handle class_loader, 275 Handle protection_domain, 276 ClassFileStream* st, 277 KlassHandle host_klass, 278 GrowableArray<Handle>* cp_patches, 279 TRAPS); 280 281 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 282 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader, 283 Handle protection_domain, 284 ClassFileStream* st, bool verify, TRAPS); 285 286 // Lookup an already loaded class. If not found NULL is returned. 287 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 288 289 // Lookup an already loaded instance or array class. 290 // Do not make any queries to class loaders; consult only the cache. 291 // If not found NULL is returned. 292 static Klass* find_instance_or_array_klass(Symbol* class_name, 293 Handle class_loader, 294 Handle protection_domain, 295 TRAPS); 296 297 // Lookup an instance or array class that has already been loaded 298 // either into the given class loader, or else into another class 299 // loader that is constrained (via loader constraints) to produce 300 // a consistent class. Do not take protection domains into account. 301 // Do not make any queries to class loaders; consult only the cache. 302 // Return NULL if the class is not found. 303 // 304 // This function is a strict superset of find_instance_or_array_klass. 305 // This function (the unchecked version) makes a conservative prediction 306 // of the result of the checked version, assuming successful lookup. 307 // If both functions return non-null, they must return the same value. 308 // Also, the unchecked version may sometimes be non-null where the 309 // checked version is null. This can occur in several ways: 310 // 1. No query has yet been made to the class loader. 311 // 2. The class loader was queried, but chose not to delegate. 312 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 313 // 4. Loading was attempted, but there was a linkage error of some sort. 314 // In all of these cases, the loader constraints on this type are 315 // satisfied, and it is safe for classes in the given class loader 316 // to manipulate strongly-typed values of the found class, subject 317 // to local linkage and access checks. 318 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 319 Handle class_loader, 320 TRAPS); 321 322 // Iterate over all klasses in dictionary 323 // Just the classes from defining class loaders 324 static void classes_do(void f(Klass*)); 325 // Added for initialize_itable_for_klass to handle exceptions 326 static void classes_do(void f(Klass*, TRAPS), TRAPS); 327 // All classes, and their class loaders 328 static void classes_do(void f(Klass*, ClassLoaderData*)); 329 330 static void placeholders_do(void f(Symbol*)); 331 332 // Iterate over all methods in all klasses in dictionary 333 static void methods_do(void f(Method*)); 334 335 // Garbage collection support 336 337 // This method applies "blk->do_oop" to all the pointers to "system" 338 // classes and loaders. 339 static void always_strong_oops_do(OopClosure* blk); 340 static void always_strong_classes_do(KlassClosure* closure); 341 342 // Unload (that is, break root links to) all unmarked classes and 343 // loaders. Returns "true" iff something was unloaded. 344 static bool do_unloading(BoolObjectClosure* is_alive, bool clean_alive = true); 345 346 // Used by DumpSharedSpaces only to remove classes that failed verification 347 static void remove_classes_in_error_state(); 348 349 static int calculate_systemdictionary_size(int loadedclasses); 350 351 // Applies "f->do_oop" to all root oops in the system dictionary. 352 static void oops_do(OopClosure* f); 353 static void roots_oops_do(OopClosure* strong, OopClosure* weak); 354 355 // System loader lock 356 static oop system_loader_lock() { return _system_loader_lock_obj; } 357 358 protected: 359 // Extended Redefine classes support (tbi) 360 static void preloaded_classes_do(KlassClosure* f); 361 static void lazily_loaded_classes_do(KlassClosure* f); 362 public: 363 // Sharing support. 364 static void reorder_dictionary(); 365 static void copy_buckets(char** top, char* end); 366 static void copy_table(char** top, char* end); 367 static void reverse(); 368 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 369 int number_of_entries); 370 // Printing 371 static void print(bool details = true); 372 static void print_shared(bool details = true); 373 static void print_class_statistics() PRODUCT_RETURN; 374 static void print_method_statistics() PRODUCT_RETURN; 375 376 // Number of contained klasses 377 // This is both fully loaded classes and classes in the process 378 // of being loaded 379 static int number_of_classes(); 380 381 // Monotonically increasing counter which grows as classes are 382 // loaded or modifications such as hot-swapping or setting/removing 383 // of breakpoints are performed 384 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 385 // Needed by evolution and breakpoint code 386 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 387 388 // Verification 389 static void verify(); 390 391 #ifdef ASSERT 392 static bool is_internal_format(Symbol* class_name); 393 #endif 394 395 // Initialization 396 static void initialize(TRAPS); 397 398 // Fast access to commonly used classes (preloaded) 399 static Klass* check_klass(Klass* k) { 400 assert(k != NULL, "preloaded klass not initialized"); 401 return k; 402 } 403 404 static Klass* check_klass_Pre( Klass* k) { return check_klass(k); } 405 static Klass* check_klass_Pre_JSR292(Klass* k) { return EnableInvokeDynamic ? check_klass(k) : k; } 406 static Klass* check_klass_Opt( Klass* k) { return k; } 407 static Klass* check_klass_Opt_Only_JDK15(Klass* k) { 408 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only"); 409 return k; 410 } 411 static Klass* check_klass_Opt_Only_JDK14NewRef(Klass* k) { 412 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only"); 413 // despite the optional loading, if you use this it must be present: 414 return check_klass(k); 415 } 416 417 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 418 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 419 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 420 int limit = (int)end_id + 1; 421 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 422 } 423 424 public: 425 #define WK_KLASS_DECLARE(name, symbol, option) \ 426 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 427 static Klass** name##_addr() { \ 428 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 429 } 430 WK_KLASSES_DO(WK_KLASS_DECLARE); 431 #undef WK_KLASS_DECLARE 432 433 static Klass* well_known_klass(WKID id) { 434 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 435 return _well_known_klasses[id]; 436 } 437 438 static Klass** well_known_klass_addr(WKID id) { 439 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 440 return &_well_known_klasses[id]; 441 } 442 443 // Local definition for direct access to the private array: 444 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 445 446 static Klass* box_klass(BasicType t) { 447 assert((uint)t < T_VOID+1, "range check"); 448 return check_klass(_box_klasses[t]); 449 } 450 static BasicType box_klass_type(Klass* k); // inverse of box_klass 451 452 // methods returning lazily loaded klasses 453 // The corresponding method to load the class must be called before calling them. 454 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 455 456 static void load_abstract_ownable_synchronizer_klass(TRAPS); 457 458 protected: 459 // Tells whether ClassLoader.loadClassInternal is present 460 static bool has_loadClassInternal() { return _has_loadClassInternal; } 461 462 // Returns the class loader data to be used when looking up/updating the 463 // system dictionary. 464 static ClassLoaderData *class_loader_data(Handle class_loader) { 465 return ClassLoaderData::class_loader_data(class_loader()); 466 } 467 468 public: 469 // Tells whether ClassLoader.checkPackageAccess is present 470 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 471 472 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 473 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 474 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 475 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 476 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 477 478 // Returns default system loader 479 static oop java_system_loader(); 480 481 // Compute the default system loader 482 static void compute_java_system_loader(TRAPS); 483 484 // Register a new class loader 485 static ClassLoaderData* register_loader(Handle class_loader, TRAPS); 486 protected: 487 // Mirrors for primitive classes (created eagerly) 488 static oop check_mirror(oop m) { 489 assert(m != NULL, "mirror not initialized"); 490 return m; 491 } 492 493 public: 494 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 495 496 // Check class loader constraints 497 static bool add_loader_constraint(Symbol* name, Handle loader1, 498 Handle loader2, TRAPS); 499 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 500 Handle loader2, bool is_method, TRAPS); 501 502 // JSR 292 503 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 504 // (asks Java to compute it if necessary, except in a compiler thread) 505 static methodHandle find_method_handle_invoker(Symbol* name, 506 Symbol* signature, 507 KlassHandle accessing_klass, 508 Handle *appendix_result, 509 Handle *method_type_result, 510 TRAPS); 511 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 512 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 513 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 514 Symbol* signature, 515 TRAPS); 516 // find a java.lang.invoke.MethodType object for a given signature 517 // (asks Java to compute it if necessary, except in a compiler thread) 518 static Handle find_method_handle_type(Symbol* signature, 519 KlassHandle accessing_klass, 520 TRAPS); 521 522 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 523 static Handle link_method_handle_constant(KlassHandle caller, 524 int ref_kind, //e.g., JVM_REF_invokeVirtual 525 KlassHandle callee, 526 Symbol* name, 527 Symbol* signature, 528 TRAPS); 529 530 // ask Java to create a dynamic call site, while linking an invokedynamic op 531 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller, 532 Handle bootstrap_method, 533 Symbol* name, 534 Symbol* type, 535 Handle *appendix_result, 536 Handle *method_type_result, 537 TRAPS); 538 539 // Utility for printing loader "name" as part of tracing constraints 540 static const char* loader_name(oop loader) { 541 return ((loader) == NULL ? "<bootloader>" : 542 InstanceKlass::cast((loader)->klass())->name()->as_C_string() ); 543 } 544 static const char* loader_name(ClassLoaderData* loader_data) { 545 return (loader_data->class_loader() == NULL ? "<bootloader>" : 546 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() ); 547 } 548 549 // Record the error when the first attempt to resolve a reference from a constant 550 // pool entry to a class fails. 551 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error); 552 static void delete_resolution_error(ConstantPool* pool); 553 static Symbol* find_resolution_error(constantPoolHandle pool, int which); 554 555 protected: 556 557 enum Constants { 558 _loader_constraint_size = 107, // number of entries in constraint table 559 _resolution_error_size = 107, // number of entries in resolution error table 560 _invoke_method_size = 139, // number of entries in invoke method table 561 _nof_buckets = 1009, // number of buckets in hash table for placeholders 562 _old_default_sdsize = 1009, // backward compat for system dictionary size 563 _prime_array_size = 8, // array of primes for system dictionary size 564 _average_depth_goal = 3 // goal for lookup length 565 }; 566 567 568 // Static variables 569 570 // hashtable sizes for system dictionary to allow growth 571 // prime numbers for system dictionary size 572 static int _sdgeneration; 573 static const int _primelist[_prime_array_size]; 574 575 // Hashtable holding loaded classes. 576 static Dictionary* _dictionary; 577 578 // Hashtable holding placeholders for classes being loaded. 579 static PlaceholderTable* _placeholders; 580 581 // Hashtable holding classes from the shared archive. 582 static Dictionary* _shared_dictionary; 583 584 // Monotonically increasing counter which grows with 585 // _number_of_classes as well as hot-swapping and breakpoint setting 586 // and removal. 587 static int _number_of_modifications; 588 589 // Lock object for system class loader 590 static oop _system_loader_lock_obj; 591 592 // Constraints on class loaders 593 static LoaderConstraintTable* _loader_constraints; 594 595 // Resolution errors 596 static ResolutionErrorTable* _resolution_errors; 597 598 // Invoke methods (JSR 292) 599 static SymbolPropertyTable* _invoke_method_table; 600 601 public: 602 // for VM_CounterDecay iteration support 603 friend class CounterDecay; 604 static Klass* try_get_next_class(); 605 606 protected: 607 static void validate_protection_domain(instanceKlassHandle klass, 608 Handle class_loader, 609 Handle protection_domain, TRAPS); 610 611 friend class VM_PopulateDumpSharedSpace; 612 friend class TraversePlaceholdersClosure; 613 static Dictionary* dictionary() { return _dictionary; } 614 static Dictionary* shared_dictionary() { return _shared_dictionary; } 615 static PlaceholderTable* placeholders() { return _placeholders; } 616 static LoaderConstraintTable* constraints() { return _loader_constraints; } 617 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 618 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 619 620 // Basic loading operations 621 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 622 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 623 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 624 // Wait on SystemDictionary_lock; unlocks lockObject before 625 // waiting; relocks lockObject with correct recursion count 626 // after waiting, but before reentering SystemDictionary_lock 627 // to preserve lock order semantics. 628 static void double_lock_wait(Handle lockObject, TRAPS); 629 static void define_instance_class(instanceKlassHandle k, TRAPS); 630 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name, 631 Handle class_loader, 632 instanceKlassHandle k, TRAPS); 633 static instanceKlassHandle load_shared_class(instanceKlassHandle ik, 634 Handle class_loader, 635 Handle protection_domain, 636 TRAPS); 637 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 638 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 639 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 640 static bool is_parallelCapable(Handle class_loader); 641 static bool is_parallelDefine(Handle class_loader); 642 643 public: 644 static instanceKlassHandle load_shared_class(Symbol* class_name, 645 Handle class_loader, 646 TRAPS); 647 static bool is_ext_class_loader(Handle class_loader); 648 649 protected: 650 static Klass* find_shared_class(Symbol* class_name); 651 652 // Setup link to hierarchy 653 static void add_to_hierarchy(instanceKlassHandle k, TRAPS); 654 655 // event based tracing 656 static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k, 657 Handle initiating_loader); 658 // We pass in the hashtable index so we can calculate it outside of 659 // the SystemDictionary_lock. 660 661 // Basic find on loaded classes 662 static Klass* find_class(int index, unsigned int hash, 663 Symbol* name, ClassLoaderData* loader_data); 664 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 665 666 // Basic find on classes in the midst of being loaded 667 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 668 669 // Updating entry in dictionary 670 // Add a completely loaded class 671 static void add_klass(int index, Symbol* class_name, 672 ClassLoaderData* loader_data, KlassHandle obj); 673 674 // Add a placeholder for a class being loaded 675 static void add_placeholder(int index, 676 Symbol* class_name, 677 ClassLoaderData* loader_data); 678 static void remove_placeholder(int index, 679 Symbol* class_name, 680 ClassLoaderData* loader_data); 681 682 // Performs cleanups after resolve_super_or_fail. This typically needs 683 // to be called on failure. 684 // Won't throw, but can block. 685 static void resolution_cleanups(Symbol* class_name, 686 ClassLoaderData* loader_data, 687 TRAPS); 688 689 // Initialization 690 static void initialize_preloaded_classes(TRAPS); 691 692 // Class loader constraints 693 static void check_constraints(int index, unsigned int hash, 694 instanceKlassHandle k, Handle loader, 695 bool defining, TRAPS); 696 static void update_dictionary(int d_index, unsigned int d_hash, 697 int p_index, unsigned int p_hash, 698 instanceKlassHandle k, Handle loader, 699 TRAPS); 700 701 // Variables holding commonly used klasses (preloaded) 702 static Klass* _well_known_klasses[]; 703 704 // Lazily loaded klasses 705 static Klass* volatile _abstract_ownable_synchronizer_klass; 706 707 // table of box klasses (int_klass, etc.) 708 static Klass* _box_klasses[T_VOID+1]; 709 710 static oop _java_system_loader; 711 712 static bool _has_loadClassInternal; 713 static bool _has_checkPackageAccess; 714 }; 715 716 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP