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 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(Cleaner_klass, sun_misc_Cleaner, Pre ) \ 132 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \ 133 \ 134 do_klass(Thread_klass, java_lang_Thread, Pre ) \ 135 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \ 136 do_klass(Properties_klass, java_util_Properties, Pre ) \ 137 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \ 138 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \ 139 do_klass(reflect_Module_klass, java_lang_reflect_Module, 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(misc_Unsafe_klass, sun_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(URL_klass, java_net_URL, Pre ) \ 177 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \ 178 do_klass(jdk_internal_misc_ClassLoaders_AppClassLoader_klass, jdk_internal_misc_ClassLoaders_AppClassLoader, Pre ) \ 179 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \ 180 do_klass(ParseUtil_klass, sun_net_www_ParseUtil, Pre ) \ 181 \ 182 /* It's NULL in non-1.4 JDKs. */ \ 183 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 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 /* Preload boxing klasses */ \ 188 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \ 189 do_klass(Character_klass, java_lang_Character, Pre ) \ 190 do_klass(Float_klass, java_lang_Float, Pre ) \ 191 do_klass(Double_klass, java_lang_Double, Pre ) \ 192 do_klass(Byte_klass, java_lang_Byte, Pre ) \ 193 do_klass(Short_klass, java_lang_Short, Pre ) \ 194 do_klass(Integer_klass, java_lang_Integer, Pre ) \ 195 do_klass(Long_klass, java_lang_Long, Pre ) \ 196 /*end*/ 197 198 199 class SystemDictionary : AllStatic { 200 friend class VMStructs; 201 friend class SystemDictionaryHandles; 202 203 public: 204 enum WKID { 205 NO_WKID = 0, 206 207 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 208 WK_KLASSES_DO(WK_KLASS_ENUM) 209 #undef WK_KLASS_ENUM 210 211 WKID_LIMIT, 212 213 FIRST_WKID = NO_WKID + 1 214 }; 215 216 enum InitOption { 217 Pre, // preloaded; error if not present 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 OPTION_LIMIT, 224 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 225 }; 226 227 228 // Returns a class with a given class name and class loader. Loads the 229 // class if needed. If not found a NoClassDefFoundError or a 230 // ClassNotFoundException is thrown, depending on the value on the 231 // throw_error flag. For most uses the throw_error argument should be set 232 // to true. 233 234 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 235 // Convenient call for null loader and protection domain. 236 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 237 protected: 238 // handle error translation for resolve_or_null results 239 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, KlassHandle klass_h, TRAPS); 240 241 public: 242 243 // Returns a class with a given class name and class loader. 244 // Loads the class if needed. If not found NULL is returned. 245 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 246 // Version with null loader and protection domain 247 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 248 249 // Resolve a superclass or superinterface. Called from ClassFileParser, 250 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 251 // "child_name" is the class whose super class or interface is being resolved. 252 static Klass* resolve_super_or_fail(Symbol* child_name, 253 Symbol* class_name, 254 Handle class_loader, 255 Handle protection_domain, 256 bool is_superclass, 257 TRAPS); 258 259 // Parse new stream. This won't update the system dictionary or 260 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 261 static Klass* parse_stream(Symbol* class_name, 262 Handle class_loader, 263 Handle protection_domain, 264 ClassFileStream* st, 265 TRAPS) { 266 KlassHandle nullHandle; 267 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD); 268 } 269 static Klass* parse_stream(Symbol* class_name, 270 Handle class_loader, 271 Handle protection_domain, 272 ClassFileStream* st, 273 KlassHandle host_klass, 274 GrowableArray<Handle>* cp_patches, 275 TRAPS); 276 277 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 278 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader, 279 Handle protection_domain, 280 ClassFileStream* st, bool verify, TRAPS); 281 282 // Lookup an already loaded class. If not found NULL is returned. 283 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 284 285 // Lookup an already loaded instance or array class. 286 // Do not make any queries to class loaders; consult only the cache. 287 // If not found NULL is returned. 288 static Klass* find_instance_or_array_klass(Symbol* class_name, 289 Handle class_loader, 290 Handle protection_domain, 291 TRAPS); 292 293 // Lookup an instance or array class that has already been loaded 294 // either into the given class loader, or else into another class 295 // loader that is constrained (via loader constraints) to produce 296 // a consistent class. Do not take protection domains into account. 297 // Do not make any queries to class loaders; consult only the cache. 298 // Return NULL if the class is not found. 299 // 300 // This function is a strict superset of find_instance_or_array_klass. 301 // This function (the unchecked version) makes a conservative prediction 302 // of the result of the checked version, assuming successful lookup. 303 // If both functions return non-null, they must return the same value. 304 // Also, the unchecked version may sometimes be non-null where the 305 // checked version is null. This can occur in several ways: 306 // 1. No query has yet been made to the class loader. 307 // 2. The class loader was queried, but chose not to delegate. 308 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 309 // 4. Loading was attempted, but there was a linkage error of some sort. 310 // In all of these cases, the loader constraints on this type are 311 // satisfied, and it is safe for classes in the given class loader 312 // to manipulate strongly-typed values of the found class, subject 313 // to local linkage and access checks. 314 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 315 Handle class_loader, 316 TRAPS); 317 318 // Iterate over all klasses in dictionary 319 // Just the classes from defining class loaders 320 static void classes_do(void f(Klass*)); 321 // Added for initialize_itable_for_klass to handle exceptions 322 static void classes_do(void f(Klass*, TRAPS), TRAPS); 323 // All classes, and their class loaders 324 static void classes_do(void f(Klass*, ClassLoaderData*)); 325 326 static void placeholders_do(void f(Symbol*)); 327 328 // Iterate over all methods in all klasses in dictionary 329 static void methods_do(void f(Method*)); 330 331 // Garbage collection support 332 333 // This method applies "blk->do_oop" to all the pointers to "system" 334 // classes and loaders. 335 static void always_strong_oops_do(OopClosure* blk); 336 static void always_strong_classes_do(KlassClosure* closure); 337 338 // Unload (that is, break root links to) all unmarked classes and 339 // loaders. Returns "true" iff something was unloaded. 340 static bool do_unloading(BoolObjectClosure* is_alive, 341 bool clean_previous_versions = true); 342 343 // Used by DumpSharedSpaces only to remove classes that failed verification 344 static void remove_classes_in_error_state(); 345 346 static int calculate_systemdictionary_size(int loadedclasses); 347 348 // Applies "f->do_oop" to all root oops in the system dictionary. 349 static void oops_do(OopClosure* f); 350 static void roots_oops_do(OopClosure* strong, OopClosure* weak); 351 352 // System loader lock 353 static oop system_loader_lock() { return _system_loader_lock_obj; } 354 355 protected: 356 // Extended Redefine classes support (tbi) 357 static void preloaded_classes_do(KlassClosure* f); 358 static void lazily_loaded_classes_do(KlassClosure* f); 359 public: 360 // Sharing support. 361 static void reorder_dictionary(); 362 static void copy_buckets(char** top, char* end); 363 static void copy_table(char** top, char* end); 364 static void reverse(); 365 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 366 int number_of_entries); 367 // Printing 368 static void print(bool details = true); 369 static void print_shared(bool details = true); 370 static void print_class_statistics() PRODUCT_RETURN; 371 static void print_method_statistics() PRODUCT_RETURN; 372 373 // Number of contained klasses 374 // This is both fully loaded classes and classes in the process 375 // of being loaded 376 static int number_of_classes(); 377 378 // Monotonically increasing counter which grows as classes are 379 // loaded or modifications such as hot-swapping or setting/removing 380 // of breakpoints are performed 381 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 382 // Needed by evolution and breakpoint code 383 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 384 385 // Verification 386 static void verify(); 387 388 #ifdef ASSERT 389 static bool is_internal_format(Symbol* class_name); 390 #endif 391 392 // Initialization 393 static void initialize(TRAPS); 394 395 // Fast access to commonly used classes (preloaded) 396 static Klass* check_klass(Klass* k) { 397 assert(k != NULL, "preloaded klass not initialized"); 398 return k; 399 } 400 401 static Klass* check_klass_Pre( Klass* k) { return check_klass(k); } 402 static Klass* check_klass_Opt( Klass* k) { return k; } 403 404 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 405 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 406 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 407 int limit = (int)end_id + 1; 408 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 409 } 410 411 public: 412 #define WK_KLASS_DECLARE(name, symbol, option) \ 413 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 414 static Klass** name##_addr() { \ 415 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 416 } 417 WK_KLASSES_DO(WK_KLASS_DECLARE); 418 #undef WK_KLASS_DECLARE 419 420 static Klass* well_known_klass(WKID id) { 421 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 422 return _well_known_klasses[id]; 423 } 424 425 static Klass** well_known_klass_addr(WKID id) { 426 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 427 return &_well_known_klasses[id]; 428 } 429 430 // Local definition for direct access to the private array: 431 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 432 433 static Klass* box_klass(BasicType t) { 434 assert((uint)t < T_VOID+1, "range check"); 435 return check_klass(_box_klasses[t]); 436 } 437 static BasicType box_klass_type(Klass* k); // inverse of box_klass 438 439 // methods returning lazily loaded klasses 440 // The corresponding method to load the class must be called before calling them. 441 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 442 443 static void load_abstract_ownable_synchronizer_klass(TRAPS); 444 445 protected: 446 // Tells whether ClassLoader.loadClassInternal is present 447 static bool has_loadClassInternal() { return _has_loadClassInternal; } 448 449 // Returns the class loader data to be used when looking up/updating the 450 // system dictionary. 451 static ClassLoaderData *class_loader_data(Handle class_loader) { 452 return ClassLoaderData::class_loader_data(class_loader()); 453 } 454 455 public: 456 // Tells whether ClassLoader.checkPackageAccess is present 457 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 458 459 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 460 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 461 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 462 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 463 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 464 465 // Returns default system loader 466 static oop java_system_loader(); 467 468 // Compute the default system loader 469 static void compute_java_system_loader(TRAPS); 470 471 // Register a new class loader 472 static ClassLoaderData* register_loader(Handle class_loader, TRAPS); 473 protected: 474 // Mirrors for primitive classes (created eagerly) 475 static oop check_mirror(oop m) { 476 assert(m != NULL, "mirror not initialized"); 477 return m; 478 } 479 480 public: 481 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 482 483 // Check class loader constraints 484 static bool add_loader_constraint(Symbol* name, Handle loader1, 485 Handle loader2, TRAPS); 486 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 487 Handle loader2, bool is_method, TRAPS); 488 489 // JSR 292 490 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 491 // (asks Java to compute it if necessary, except in a compiler thread) 492 static methodHandle find_method_handle_invoker(Symbol* name, 493 Symbol* signature, 494 KlassHandle accessing_klass, 495 Handle *appendix_result, 496 Handle *method_type_result, 497 TRAPS); 498 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 499 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 500 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 501 Symbol* signature, 502 TRAPS); 503 // find a java.lang.invoke.MethodType object for a given signature 504 // (asks Java to compute it if necessary, except in a compiler thread) 505 static Handle find_method_handle_type(Symbol* signature, 506 KlassHandle accessing_klass, 507 TRAPS); 508 509 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 510 static Handle link_method_handle_constant(KlassHandle caller, 511 int ref_kind, //e.g., JVM_REF_invokeVirtual 512 KlassHandle callee, 513 Symbol* name, 514 Symbol* signature, 515 TRAPS); 516 517 // ask Java to create a dynamic call site, while linking an invokedynamic op 518 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller, 519 Handle bootstrap_method, 520 Symbol* name, 521 Symbol* type, 522 Handle *appendix_result, 523 Handle *method_type_result, 524 TRAPS); 525 526 // Utility for printing loader "name" as part of tracing constraints 527 static const char* loader_name(oop loader) { 528 return ((loader) == NULL ? "<bootloader>" : 529 InstanceKlass::cast((loader)->klass())->name()->as_C_string() ); 530 } 531 static const char* loader_name(ClassLoaderData* loader_data) { 532 return (loader_data->class_loader() == NULL ? "<bootloader>" : 533 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() ); 534 } 535 536 // Record the error when the first attempt to resolve a reference from a constant 537 // pool entry to a class fails. 538 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error, 539 Symbol* message); 540 static void delete_resolution_error(ConstantPool* pool); 541 static Symbol* find_resolution_error(constantPoolHandle pool, int which, 542 Symbol** message); 543 544 protected: 545 546 enum Constants { 547 _loader_constraint_size = 107, // number of entries in constraint table 548 _resolution_error_size = 107, // number of entries in resolution error table 549 _invoke_method_size = 139, // number of entries in invoke method table 550 _nof_buckets = 1009, // number of buckets in hash table for placeholders 551 _old_default_sdsize = 1009, // backward compat for system dictionary size 552 _prime_array_size = 8, // array of primes for system dictionary size 553 _average_depth_goal = 3 // goal for lookup length 554 }; 555 556 557 // Static variables 558 559 // hashtable sizes for system dictionary to allow growth 560 // prime numbers for system dictionary size 561 static int _sdgeneration; 562 static const int _primelist[_prime_array_size]; 563 564 // Hashtable holding loaded classes. 565 static Dictionary* _dictionary; 566 567 // Hashtable holding placeholders for classes being loaded. 568 static PlaceholderTable* _placeholders; 569 570 // Hashtable holding classes from the shared archive. 571 static Dictionary* _shared_dictionary; 572 573 // Monotonically increasing counter which grows with 574 // _number_of_classes as well as hot-swapping and breakpoint setting 575 // and removal. 576 static int _number_of_modifications; 577 578 // Lock object for system class loader 579 static oop _system_loader_lock_obj; 580 581 // Constraints on class loaders 582 static LoaderConstraintTable* _loader_constraints; 583 584 // Resolution errors 585 static ResolutionErrorTable* _resolution_errors; 586 587 // Invoke methods (JSR 292) 588 static SymbolPropertyTable* _invoke_method_table; 589 590 public: 591 // for VM_CounterDecay iteration support 592 friend class CounterDecay; 593 static Klass* try_get_next_class(); 594 595 protected: 596 static void validate_protection_domain(instanceKlassHandle klass, 597 Handle class_loader, 598 Handle protection_domain, TRAPS); 599 600 friend class VM_PopulateDumpSharedSpace; 601 friend class TraversePlaceholdersClosure; 602 static Dictionary* dictionary() { return _dictionary; } 603 static Dictionary* shared_dictionary() { return _shared_dictionary; } 604 static PlaceholderTable* placeholders() { return _placeholders; } 605 static LoaderConstraintTable* constraints() { return _loader_constraints; } 606 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 607 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 608 609 // Basic loading operations 610 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 611 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 612 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 613 // Wait on SystemDictionary_lock; unlocks lockObject before 614 // waiting; relocks lockObject with correct recursion count 615 // after waiting, but before reentering SystemDictionary_lock 616 // to preserve lock order semantics. 617 static void double_lock_wait(Handle lockObject, TRAPS); 618 static void define_instance_class(instanceKlassHandle k, TRAPS); 619 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name, 620 Handle class_loader, 621 instanceKlassHandle k, TRAPS); 622 static instanceKlassHandle load_shared_class(instanceKlassHandle ik, 623 Handle class_loader, 624 Handle protection_domain, 625 TRAPS); 626 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 627 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 628 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 629 static bool is_parallelCapable(Handle class_loader); 630 static bool is_parallelDefine(Handle class_loader); 631 632 public: 633 static instanceKlassHandle load_shared_class(Symbol* class_name, 634 Handle class_loader, 635 TRAPS); 636 static bool is_ext_class_loader(Handle class_loader); 637 638 protected: 639 static Klass* find_shared_class(Symbol* class_name); 640 641 // Setup link to hierarchy 642 static void add_to_hierarchy(instanceKlassHandle k, TRAPS); 643 644 // event based tracing 645 static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k, 646 Handle initiating_loader); 647 // We pass in the hashtable index so we can calculate it outside of 648 // the SystemDictionary_lock. 649 650 // Basic find on loaded classes 651 static Klass* find_class(int index, unsigned int hash, 652 Symbol* name, ClassLoaderData* loader_data); 653 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 654 655 // Basic find on classes in the midst of being loaded 656 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 657 658 // Updating entry in dictionary 659 // Add a completely loaded class 660 static void add_klass(int index, Symbol* class_name, 661 ClassLoaderData* loader_data, KlassHandle obj); 662 663 // Add a placeholder for a class being loaded 664 static void add_placeholder(int index, 665 Symbol* class_name, 666 ClassLoaderData* loader_data); 667 static void remove_placeholder(int index, 668 Symbol* class_name, 669 ClassLoaderData* loader_data); 670 671 // Performs cleanups after resolve_super_or_fail. This typically needs 672 // to be called on failure. 673 // Won't throw, but can block. 674 static void resolution_cleanups(Symbol* class_name, 675 ClassLoaderData* loader_data, 676 TRAPS); 677 678 // Initialization 679 static void initialize_preloaded_classes(TRAPS); 680 681 // Class loader constraints 682 static void check_constraints(int index, unsigned int hash, 683 instanceKlassHandle k, Handle loader, 684 bool defining, TRAPS); 685 static void update_dictionary(int d_index, unsigned int d_hash, 686 int p_index, unsigned int p_hash, 687 instanceKlassHandle k, Handle loader, 688 TRAPS); 689 690 // Variables holding commonly used klasses (preloaded) 691 static Klass* _well_known_klasses[]; 692 693 // Lazily loaded klasses 694 static Klass* volatile _abstract_ownable_synchronizer_klass; 695 696 // table of box klasses (int_klass, etc.) 697 static Klass* _box_klasses[T_VOID+1]; 698 699 static oop _java_system_loader; 700 701 static bool _has_loadClassInternal; 702 static bool _has_checkPackageAccess; 703 }; 704 705 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP