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