1 /* 2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP 26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP 27 28 #include "classfile/classLoader.hpp" 29 #include "classfile/systemDictionary_ext.hpp" 30 #include "jvmci/systemDictionary_jvmci.hpp" 31 #include "oops/objArrayOop.hpp" 32 #include "oops/symbol.hpp" 33 #include "runtime/java.hpp" 34 #include "runtime/reflectionUtils.hpp" 35 #include "utilities/hashtable.hpp" 36 #include "utilities/hashtable.inline.hpp" 37 38 // The 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 ClassFileStream; 75 class Dictionary; 76 class PlaceholderTable; 77 class LoaderConstraintTable; 78 template <MEMFLAGS F> class HashtableBucket; 79 class ResolutionErrorTable; 80 class SymbolPropertyTable; 81 class ProtectionDomainCacheTable; 82 class ProtectionDomainCacheEntry; 83 class GCTimer; 84 85 // Certain classes are preloaded, such as java.lang.Object and java.lang.String. 86 // They are all "well-known", in the sense that no class loader is allowed 87 // to provide a different definition. 88 // 89 // These klasses must all have names defined in vmSymbols. 90 91 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 92 93 // Each well-known class has a short klass name (like object_klass), 94 // a vmSymbol name (like java_lang_Object), and a flag word 95 // that makes some minor distinctions, like whether the klass 96 // is preloaded, optional, release-specific, etc. 97 // The order of these definitions is significant; it is the order in which 98 // preloading is actually performed by initialize_preloaded_classes. 99 100 #define WK_KLASSES_DO(do_klass) \ 101 /* well-known classes */ \ 102 do_klass(Object_klass, java_lang_Object, Pre ) \ 103 do_klass(String_klass, java_lang_String, Pre ) \ 104 do_klass(Class_klass, java_lang_Class, Pre ) \ 105 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \ 106 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \ 107 do_klass(Serializable_klass, java_io_Serializable, Pre ) \ 108 do_klass(System_klass, java_lang_System, Pre ) \ 109 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \ 110 do_klass(Error_klass, java_lang_Error, Pre ) \ 111 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \ 112 do_klass(Exception_klass, java_lang_Exception, Pre ) \ 113 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \ 114 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \ 115 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \ 116 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \ 117 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \ 118 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \ 119 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \ 120 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \ 121 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \ 122 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \ 123 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \ 124 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \ 125 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \ 126 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \ 127 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \ 128 \ 129 /* Preload ref klasses and set reference types */ \ 130 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \ 131 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \ 132 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \ 133 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \ 134 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \ 135 \ 136 do_klass(Thread_klass, java_lang_Thread, Pre ) \ 137 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \ 138 do_klass(Properties_klass, java_util_Properties, Pre ) \ 139 do_klass(Module_klass, java_lang_Module, Pre ) \ 140 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \ 141 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \ 142 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \ 143 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \ 144 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \ 145 \ 146 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 147 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 148 do_klass(reflect_MagicAccessorImpl_klass, reflect_MagicAccessorImpl, Opt ) \ 149 do_klass(reflect_MethodAccessorImpl_klass, reflect_MethodAccessorImpl, Pre ) \ 150 do_klass(reflect_ConstructorAccessorImpl_klass, reflect_ConstructorAccessorImpl, Pre ) \ 151 do_klass(reflect_DelegatingClassLoader_klass, reflect_DelegatingClassLoader, Opt ) \ 152 do_klass(reflect_ConstantPool_klass, reflect_ConstantPool, Opt ) \ 153 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, reflect_UnsafeStaticFieldAccessorImpl, Opt ) \ 154 do_klass(reflect_CallerSensitive_klass, reflect_CallerSensitive, Opt ) \ 155 \ 156 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 157 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \ 158 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \ 159 do_klass(VarHandle_klass, java_lang_invoke_VarHandle, Pre ) \ 160 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \ 161 do_klass(ResolvedMethodName_klass, java_lang_invoke_ResolvedMethodName, Pre ) \ 162 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \ 163 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \ 164 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \ 165 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \ 166 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \ 167 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre ) \ 168 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \ 169 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \ 170 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \ 171 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 172 \ 173 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \ 174 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \ 175 do_klass(internal_Unsafe_klass, jdk_internal_misc_Unsafe, Pre ) \ 176 do_klass(module_Modules_klass, jdk_internal_module_Modules, Pre ) \ 177 \ 178 /* support for CDS */ \ 179 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \ 180 do_klass(File_klass, java_io_File, Pre ) \ 181 do_klass(URL_klass, java_net_URL, Pre ) \ 182 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \ 183 do_klass(jdk_internal_loader_ClassLoaders_AppClassLoader_klass, jdk_internal_loader_ClassLoaders_AppClassLoader, Pre ) \ 184 do_klass(jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass, jdk_internal_loader_ClassLoaders_PlatformClassLoader, Pre ) \ 185 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \ 186 do_klass(ParseUtil_klass, sun_net_www_ParseUtil, Pre ) \ 187 \ 188 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 189 \ 190 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 191 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \ 192 \ 193 /* Stack Walking */ \ 194 do_klass(StackWalker_klass, java_lang_StackWalker, Opt ) \ 195 do_klass(AbstractStackWalker_klass, java_lang_StackStreamFactory_AbstractStackWalker, Opt ) \ 196 do_klass(StackFrameInfo_klass, java_lang_StackFrameInfo, Opt ) \ 197 do_klass(LiveStackFrameInfo_klass, java_lang_LiveStackFrameInfo, Opt ) \ 198 \ 199 /* Preload boxing klasses */ \ 200 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \ 201 do_klass(Character_klass, java_lang_Character, Pre ) \ 202 do_klass(Float_klass, java_lang_Float, Pre ) \ 203 do_klass(Double_klass, java_lang_Double, Pre ) \ 204 do_klass(Byte_klass, java_lang_Byte, Pre ) \ 205 do_klass(Short_klass, java_lang_Short, Pre ) \ 206 do_klass(Integer_klass, java_lang_Integer, Pre ) \ 207 do_klass(Long_klass, java_lang_Long, Pre ) \ 208 \ 209 /* Extensions */ \ 210 WK_KLASSES_DO_EXT(do_klass) \ 211 /* JVMCI classes. These are loaded on-demand. */ \ 212 JVMCI_WK_KLASSES_DO(do_klass) \ 213 \ 214 /*end*/ 215 216 217 class SystemDictionary : AllStatic { 218 friend class VMStructs; 219 friend class SystemDictionaryHandles; 220 friend class SharedClassUtil; 221 222 public: 223 enum WKID { 224 NO_WKID = 0, 225 226 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 227 WK_KLASSES_DO(WK_KLASS_ENUM) 228 #undef WK_KLASS_ENUM 229 230 WKID_LIMIT, 231 232 #if INCLUDE_JVMCI 233 FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(JVMCI_klass), 234 LAST_JVMCI_WKID = WK_KLASS_ENUM_NAME(Value_klass), 235 #endif 236 237 FIRST_WKID = NO_WKID + 1 238 }; 239 240 enum InitOption { 241 Pre, // preloaded; error if not present 242 243 // Order is significant. Options before this point require resolve_or_fail. 244 // Options after this point will use resolve_or_null instead. 245 246 Opt, // preload tried; NULL if not present 247 #if INCLUDE_JVMCI 248 Jvmci, // preload tried; error if not present if JVMCI enabled 249 #endif 250 OPTION_LIMIT, 251 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 252 }; 253 254 255 // Returns a class with a given class name and class loader. Loads the 256 // class if needed. If not found a NoClassDefFoundError or a 257 // ClassNotFoundException is thrown, depending on the value on the 258 // throw_error flag. For most uses the throw_error argument should be set 259 // to true. 260 261 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 262 // Convenient call for null loader and protection domain. 263 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 264 protected: 265 // handle error translation for resolve_or_null results 266 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, Klass* klass, TRAPS); 267 268 public: 269 270 // Returns a class with a given class name and class loader. 271 // Loads the class if needed. If not found NULL is returned. 272 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 273 // Version with null loader and protection domain 274 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 275 276 // Resolve a superclass or superinterface. Called from ClassFileParser, 277 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 278 // "child_name" is the class whose super class or interface is being resolved. 279 static Klass* resolve_super_or_fail(Symbol* child_name, 280 Symbol* class_name, 281 Handle class_loader, 282 Handle protection_domain, 283 bool is_superclass, 284 TRAPS); 285 286 // Parse new stream. This won't update the system dictionary or 287 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 288 // Also used by Unsafe_DefineAnonymousClass 289 static InstanceKlass* parse_stream(Symbol* class_name, 290 Handle class_loader, 291 Handle protection_domain, 292 ClassFileStream* st, 293 TRAPS) { 294 return parse_stream(class_name, 295 class_loader, 296 protection_domain, 297 st, 298 NULL, // host klass 299 NULL, // cp_patches 300 THREAD); 301 } 302 static InstanceKlass* parse_stream(Symbol* class_name, 303 Handle class_loader, 304 Handle protection_domain, 305 ClassFileStream* st, 306 const InstanceKlass* host_klass, 307 GrowableArray<Handle>* cp_patches, 308 TRAPS); 309 310 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 311 static InstanceKlass* resolve_from_stream(Symbol* class_name, 312 Handle class_loader, 313 Handle protection_domain, 314 ClassFileStream* st, 315 TRAPS); 316 317 // Lookup an already loaded class. If not found NULL is returned. 318 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 319 320 // Lookup an already loaded instance or array class. 321 // Do not make any queries to class loaders; consult only the cache. 322 // If not found NULL is returned. 323 static Klass* find_instance_or_array_klass(Symbol* class_name, 324 Handle class_loader, 325 Handle protection_domain, 326 TRAPS); 327 328 // Lookup an instance or array class that has already been loaded 329 // either into the given class loader, or else into another class 330 // loader that is constrained (via loader constraints) to produce 331 // a consistent class. Do not take protection domains into account. 332 // Do not make any queries to class loaders; consult only the cache. 333 // Return NULL if the class is not found. 334 // 335 // This function is a strict superset of find_instance_or_array_klass. 336 // This function (the unchecked version) makes a conservative prediction 337 // of the result of the checked version, assuming successful lookup. 338 // If both functions return non-null, they must return the same value. 339 // Also, the unchecked version may sometimes be non-null where the 340 // checked version is null. This can occur in several ways: 341 // 1. No query has yet been made to the class loader. 342 // 2. The class loader was queried, but chose not to delegate. 343 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 344 // 4. Loading was attempted, but there was a linkage error of some sort. 345 // In all of these cases, the loader constraints on this type are 346 // satisfied, and it is safe for classes in the given class loader 347 // to manipulate strongly-typed values of the found class, subject 348 // to local linkage and access checks. 349 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 350 Handle class_loader, 351 TRAPS); 352 353 // Iterate over all methods in all klasses 354 static void methods_do(void f(Method*)); 355 356 // Garbage collection support 357 358 // This method applies "blk->do_oop" to all the pointers to "system" 359 // classes and loaders. 360 static void always_strong_oops_do(OopClosure* blk); 361 362 // Unload (that is, break root links to) all unmarked classes and 363 // loaders. Returns "true" iff something was unloaded. 364 static bool do_unloading(BoolObjectClosure* is_alive, 365 GCTimer* gc_timer, 366 bool do_cleaning = true); 367 368 // Used by DumpSharedSpaces only to remove classes that failed verification 369 static void remove_classes_in_error_state(); 370 371 static int calculate_systemdictionary_size(int loadedclasses); 372 373 // Applies "f->do_oop" to all root oops in the system dictionary. 374 static void oops_do(OopClosure* f); 375 static void roots_oops_do(OopClosure* strong, OopClosure* weak); 376 377 // System loader lock 378 static oop system_loader_lock() { return _system_loader_lock_obj; } 379 380 public: 381 // Sharing support. 382 static void reorder_dictionary(); 383 static void copy_buckets(char** top, char* end); 384 static void copy_table(char** top, char* end); 385 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 386 int number_of_entries); 387 // Printing 388 static void print(bool details = true); 389 static void print_shared(bool details = true); 390 391 // Monotonically increasing counter which grows as classes are 392 // loaded or modifications such as hot-swapping or setting/removing 393 // of breakpoints are performed 394 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 395 // Needed by evolution and breakpoint code 396 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 397 398 // Verification 399 static void verify(); 400 401 // Initialization 402 static void initialize(TRAPS); 403 404 // Checked fast access to commonly used classes - mostly preloaded 405 static InstanceKlass* check_klass(InstanceKlass* k) { 406 assert(k != NULL, "klass not loaded"); 407 return k; 408 } 409 410 static InstanceKlass* check_klass_Pre(InstanceKlass* k) { return check_klass(k); } 411 static InstanceKlass* check_klass_Opt(InstanceKlass* k) { return k; } 412 413 JVMCI_ONLY(static InstanceKlass* check_klass_Jvmci(InstanceKlass* k) { return k; }) 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 InstanceKlass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 425 static InstanceKlass** 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 InstanceKlass* 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 InstanceKlass** 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 InstanceKlass* 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 InstanceKlass* 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(Klass* klass, 504 Symbol* name, 505 Symbol* signature, 506 Klass* accessing_klass, 507 Handle *appendix_result, 508 Handle *method_type_result, 509 TRAPS); 510 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 511 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 512 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 513 Symbol* signature, 514 TRAPS); 515 // find a java.lang.invoke.MethodType object for a given signature 516 // (asks Java to compute it if necessary, except in a compiler thread) 517 static Handle find_method_handle_type(Symbol* signature, 518 Klass* accessing_klass, 519 TRAPS); 520 521 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 522 static Handle link_method_handle_constant(Klass* caller, 523 int ref_kind, //e.g., JVM_REF_invokeVirtual 524 Klass* callee, 525 Symbol* name, 526 Symbol* signature, 527 TRAPS); 528 529 // ask Java to create a dynamic call site, while linking an invokedynamic op 530 static methodHandle find_dynamic_call_site_invoker(Klass* caller, 531 Handle bootstrap_method, 532 Symbol* name, 533 Symbol* type, 534 Handle *appendix_result, 535 Handle *method_type_result, 536 TRAPS); 537 538 // Utility for printing loader "name" as part of tracing constraints 539 static const char* loader_name(const oop loader); 540 static const char* loader_name(const ClassLoaderData* loader_data); 541 542 // Record the error when the first attempt to resolve a reference from a constant 543 // pool entry to a class fails. 544 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error, 545 Symbol* message); 546 static void delete_resolution_error(ConstantPool* pool); 547 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which, 548 Symbol** message); 549 550 551 static ProtectionDomainCacheEntry* cache_get(Handle protection_domain); 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 _shared_dictionary_size = 1009, // number of entries in shared dictionary 560 _placeholder_table_size = 1009 // number of entries in hash table for placeholders 561 }; 562 563 564 // Static tables owned by the SystemDictionary 565 566 // Hashtable holding placeholders for classes being loaded. 567 static PlaceholderTable* _placeholders; 568 569 // Hashtable holding classes from the shared archive. 570 static Dictionary* _shared_dictionary; 571 572 // Monotonically increasing counter which grows with 573 // loading classes as well as hot-swapping and breakpoint setting 574 // and removal. 575 static int _number_of_modifications; 576 577 // Lock object for system class loader 578 static oop _system_loader_lock_obj; 579 580 // Constraints on class loaders 581 static LoaderConstraintTable* _loader_constraints; 582 583 // Resolution errors 584 static ResolutionErrorTable* _resolution_errors; 585 586 // Invoke methods (JSR 292) 587 static SymbolPropertyTable* _invoke_method_table; 588 589 // ProtectionDomain cache 590 static ProtectionDomainCacheTable* _pd_cache_table; 591 592 protected: 593 static void validate_protection_domain(InstanceKlass* klass, 594 Handle class_loader, 595 Handle protection_domain, TRAPS); 596 597 friend class VM_PopulateDumpSharedSpace; 598 friend class TraversePlaceholdersClosure; 599 static Dictionary* shared_dictionary() { return _shared_dictionary; } 600 static PlaceholderTable* placeholders() { return _placeholders; } 601 static LoaderConstraintTable* constraints() { return _loader_constraints; } 602 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 603 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 604 605 // Basic loading operations 606 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 607 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 608 static InstanceKlass* handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 609 // Wait on SystemDictionary_lock; unlocks lockObject before 610 // waiting; relocks lockObject with correct recursion count 611 // after waiting, but before reentering SystemDictionary_lock 612 // to preserve lock order semantics. 613 static void double_lock_wait(Handle lockObject, TRAPS); 614 static void define_instance_class(InstanceKlass* k, TRAPS); 615 static InstanceKlass* find_or_define_instance_class(Symbol* class_name, 616 Handle class_loader, 617 InstanceKlass* k, TRAPS); 618 static bool is_shared_class_visible(Symbol* class_name, InstanceKlass* ik, 619 Handle class_loader, TRAPS); 620 static InstanceKlass* load_shared_class(InstanceKlass* ik, 621 Handle class_loader, 622 Handle protection_domain, 623 TRAPS); 624 static InstanceKlass* load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 625 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 626 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 627 static bool is_parallelCapable(Handle class_loader); 628 static bool is_parallelDefine(Handle class_loader); 629 630 public: 631 static InstanceKlass* load_shared_class(Symbol* class_name, 632 Handle class_loader, 633 TRAPS); 634 static bool is_system_class_loader(oop class_loader); 635 static bool is_platform_class_loader(oop class_loader); 636 637 protected: 638 static InstanceKlass* find_shared_class(Symbol* class_name); 639 640 // Setup link to hierarchy 641 static void add_to_hierarchy(InstanceKlass* k, TRAPS); 642 643 // We pass in the hashtable index so we can calculate it outside of 644 // the SystemDictionary_lock. 645 646 // Basic find on loaded classes 647 static InstanceKlass* find_class(int index, unsigned int hash, 648 Symbol* name, Dictionary* dictionary); 649 static InstanceKlass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 650 651 // Basic find on classes in the midst of being loaded 652 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 653 654 // Add a placeholder for a class being loaded 655 static void add_placeholder(int index, 656 Symbol* class_name, 657 ClassLoaderData* loader_data); 658 static void remove_placeholder(int index, 659 Symbol* class_name, 660 ClassLoaderData* loader_data); 661 662 // Performs cleanups after resolve_super_or_fail. This typically needs 663 // to be called on failure. 664 // Won't throw, but can block. 665 static void resolution_cleanups(Symbol* class_name, 666 ClassLoaderData* loader_data, 667 TRAPS); 668 669 // Initialization 670 static void initialize_preloaded_classes(TRAPS); 671 672 // Class loader constraints 673 static void check_constraints(int index, unsigned int hash, 674 InstanceKlass* k, Handle loader, 675 bool defining, TRAPS); 676 static void update_dictionary(int d_index, unsigned int d_hash, 677 int p_index, unsigned int p_hash, 678 InstanceKlass* k, Handle loader, 679 TRAPS); 680 681 // Variables holding commonly used klasses (preloaded) 682 static InstanceKlass* _well_known_klasses[]; 683 684 // Lazily loaded klasses 685 static InstanceKlass* volatile _abstract_ownable_synchronizer_klass; 686 687 // table of box klasses (int_klass, etc.) 688 static InstanceKlass* _box_klasses[T_VOID+1]; 689 690 static oop _java_system_loader; 691 692 static bool _has_loadClassInternal; 693 static bool _has_checkPackageAccess; 694 }; 695 696 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP