1 /* 2 * Copyright (c) 1997, 2018, 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 "runtime/signature.hpp" 36 #include "utilities/hashtable.hpp" 37 #include "utilities/hashtable.inline.hpp" 38 39 // The dictionary in each ClassLoaderData stores all loaded classes, either 40 // initiatied by its class loader or defined by its class loader: 41 // 42 // class loader -> ClassLoaderData -> [class, protection domain set] 43 // 44 // Classes are loaded lazily. The default VM class loader is 45 // represented as NULL. 46 47 // The underlying data structure is an open hash table (Dictionary) per 48 // ClassLoaderData with a fixed number of buckets. During loading the 49 // class loader object is locked, (for the VM loader a private lock object is used). 50 // The global SystemDictionary_lock is held for all additions into the ClassLoaderData 51 // dictionaries. TODO: fix lock granularity so that class loading can 52 // be done concurrently, but only by different loaders. 53 // 54 // During loading a placeholder (name, loader) is temporarily placed in 55 // a side data structure, and is used to detect ClassCircularityErrors 56 // and to perform verification during GC. A GC can occur in the midst 57 // of class loading, as we call out to Java, have to take locks, etc. 58 // 59 // When class loading is finished, a new entry is added to the dictionary 60 // of the class loader and the placeholder is removed. Note that the protection 61 // domain field of the dictionary entry has not yet been filled in when 62 // the "real" dictionary entry is created. 63 // 64 // Clients of this class who are interested in finding if a class has 65 // been completely loaded -- not classes in the process of being loaded -- 66 // can read the dictionary unlocked. This is safe because 67 // - entries are only deleted at safepoints 68 // - readers cannot come to a safepoint while actively examining 69 // an entry (an entry cannot be deleted from under a reader) 70 // - entries must be fully formed before they are available to concurrent 71 // readers (we must ensure write ordering) 72 // 73 // Note that placeholders are deleted at any time, as they are removed 74 // when a class is completely loaded. Therefore, readers as well as writers 75 // of placeholders must hold the SystemDictionary_lock. 76 // 77 78 class ClassFileStream; 79 class Dictionary; 80 class PlaceholderTable; 81 class LoaderConstraintTable; 82 template <MEMFLAGS F> class HashtableBucket; 83 class ResolutionErrorTable; 84 class SymbolPropertyTable; 85 class ProtectionDomainCacheTable; 86 class ProtectionDomainCacheEntry; 87 class GCTimer; 88 89 // Certain classes are preloaded, such as java.lang.Object and java.lang.String. 90 // They are all "well-known", in the sense that no class loader is allowed 91 // to provide a different definition. 92 // 93 // These klasses must all have names defined in vmSymbols. 94 95 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 96 97 // Each well-known class has a short klass name (like object_klass), 98 // a vmSymbol name (like java_lang_Object), and a flag word 99 // that makes some minor distinctions, like whether the klass 100 // is preloaded, optional, release-specific, etc. 101 // The order of these definitions is significant; it is the order in which 102 // preloading is actually performed by initialize_preloaded_classes. 103 104 #define WK_KLASSES_DO(do_klass) \ 105 /* well-known classes */ \ 106 do_klass(Object_klass, java_lang_Object, Pre ) \ 107 do_klass(String_klass, java_lang_String, Pre ) \ 108 do_klass(Class_klass, java_lang_Class, Pre ) \ 109 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \ 110 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \ 111 do_klass(Serializable_klass, java_io_Serializable, Pre ) \ 112 do_klass(System_klass, java_lang_System, Pre ) \ 113 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \ 114 do_klass(Error_klass, java_lang_Error, Pre ) \ 115 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \ 116 do_klass(Exception_klass, java_lang_Exception, Pre ) \ 117 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \ 118 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \ 119 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \ 120 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \ 121 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \ 122 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \ 123 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \ 124 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \ 125 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \ 126 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \ 127 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \ 128 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \ 129 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \ 130 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \ 131 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \ 132 \ 133 /* Preload ref klasses and set reference types */ \ 134 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \ 135 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \ 136 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \ 137 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \ 138 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \ 139 \ 140 do_klass(Thread_klass, java_lang_Thread, Pre ) \ 141 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \ 142 do_klass(Properties_klass, java_util_Properties, Pre ) \ 143 do_klass(Module_klass, java_lang_Module, Pre ) \ 144 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \ 145 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \ 146 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \ 147 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \ 148 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \ 149 \ 150 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 151 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 152 do_klass(reflect_MagicAccessorImpl_klass, reflect_MagicAccessorImpl, Opt ) \ 153 do_klass(reflect_MethodAccessorImpl_klass, reflect_MethodAccessorImpl, Pre ) \ 154 do_klass(reflect_ConstructorAccessorImpl_klass, reflect_ConstructorAccessorImpl, Pre ) \ 155 do_klass(reflect_DelegatingClassLoader_klass, reflect_DelegatingClassLoader, Opt ) \ 156 do_klass(reflect_ConstantPool_klass, reflect_ConstantPool, Opt ) \ 157 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, reflect_UnsafeStaticFieldAccessorImpl, Opt ) \ 158 do_klass(reflect_CallerSensitive_klass, reflect_CallerSensitive, Opt ) \ 159 \ 160 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 161 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \ 162 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \ 163 do_klass(VarHandle_klass, java_lang_invoke_VarHandle, Pre ) \ 164 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \ 165 do_klass(ResolvedMethodName_klass, java_lang_invoke_ResolvedMethodName, Pre ) \ 166 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \ 167 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \ 168 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \ 169 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \ 170 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \ 171 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre ) \ 172 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \ 173 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \ 174 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \ 175 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 176 \ 177 do_klass(AssertionStatusDirectives_klass, java_lang_AssertionStatusDirectives, Pre ) \ 178 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \ 179 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \ 180 do_klass(internal_Unsafe_klass, jdk_internal_misc_Unsafe, Pre ) \ 181 do_klass(module_Modules_klass, jdk_internal_module_Modules, Pre ) \ 182 \ 183 /* support for CDS */ \ 184 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \ 185 do_klass(File_klass, java_io_File, Pre ) \ 186 do_klass(URL_klass, java_net_URL, Pre ) \ 187 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \ 188 do_klass(jdk_internal_loader_ClassLoaders_AppClassLoader_klass, jdk_internal_loader_ClassLoaders_AppClassLoader, Pre ) \ 189 do_klass(jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass, jdk_internal_loader_ClassLoaders_PlatformClassLoader, Pre ) \ 190 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \ 191 do_klass(ParseUtil_klass, sun_net_www_ParseUtil, Pre ) \ 192 \ 193 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 194 \ 195 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 196 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \ 197 \ 198 /* Stack Walking */ \ 199 do_klass(StackWalker_klass, java_lang_StackWalker, Opt ) \ 200 do_klass(AbstractStackWalker_klass, java_lang_StackStreamFactory_AbstractStackWalker, Opt ) \ 201 do_klass(StackFrameInfo_klass, java_lang_StackFrameInfo, Opt ) \ 202 do_klass(LiveStackFrameInfo_klass, java_lang_LiveStackFrameInfo, Opt ) \ 203 \ 204 /* Preload boxing klasses */ \ 205 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \ 206 do_klass(Character_klass, java_lang_Character, Pre ) \ 207 do_klass(Float_klass, java_lang_Float, Pre ) \ 208 do_klass(Double_klass, java_lang_Double, Pre ) \ 209 do_klass(Byte_klass, java_lang_Byte, Pre ) \ 210 do_klass(Short_klass, java_lang_Short, Pre ) \ 211 do_klass(Integer_klass, java_lang_Integer, Pre ) \ 212 do_klass(Long_klass, java_lang_Long, Pre ) \ 213 \ 214 /* Extensions */ \ 215 WK_KLASSES_DO_EXT(do_klass) \ 216 /* JVMCI classes. These are loaded on-demand. */ \ 217 JVMCI_WK_KLASSES_DO(do_klass) \ 218 \ 219 /*end*/ 220 221 222 class SystemDictionary : AllStatic { 223 friend class VMStructs; 224 friend class SystemDictionaryHandles; 225 friend class SharedClassUtil; 226 227 public: 228 enum WKID { 229 NO_WKID = 0, 230 231 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 232 WK_KLASSES_DO(WK_KLASS_ENUM) 233 #undef WK_KLASS_ENUM 234 235 WKID_LIMIT, 236 237 #if INCLUDE_JVMCI 238 FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(JVMCI_klass), 239 LAST_JVMCI_WKID = WK_KLASS_ENUM_NAME(Value_klass), 240 #endif 241 242 FIRST_WKID = NO_WKID + 1 243 }; 244 245 enum InitOption { 246 Pre, // preloaded; error if not present 247 248 // Order is significant. Options before this point require resolve_or_fail. 249 // Options after this point will use resolve_or_null instead. 250 251 Opt, // preload tried; NULL if not present 252 #if INCLUDE_JVMCI 253 Jvmci, // preload tried; error if not present if JVMCI enabled 254 #endif 255 OPTION_LIMIT, 256 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 257 }; 258 259 260 // Returns a class with a given class name and class loader. Loads the 261 // class if needed. If not found a NoClassDefFoundError or a 262 // ClassNotFoundException is thrown, depending on the value on the 263 // throw_error flag. For most uses the throw_error argument should be set 264 // to true. 265 266 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 267 // Convenient call for null loader and protection domain. 268 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 269 protected: 270 // handle error translation for resolve_or_null results 271 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, Klass* klass, TRAPS); 272 273 public: 274 275 // Returns a class with a given class name and class loader. 276 // Loads the class if needed. If not found NULL is returned. 277 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 278 // Version with null loader and protection domain 279 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 280 281 // Resolve a superclass or superinterface. Called from ClassFileParser, 282 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 283 // "child_name" is the class whose super class or interface is being resolved. 284 static Klass* resolve_super_or_fail(Symbol* child_name, 285 Symbol* class_name, 286 Handle class_loader, 287 Handle protection_domain, 288 bool is_superclass, 289 TRAPS); 290 291 // Parse new stream. This won't update the dictionary or 292 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 293 // Also used by Unsafe_DefineAnonymousClass 294 static InstanceKlass* parse_stream(Symbol* class_name, 295 Handle class_loader, 296 Handle protection_domain, 297 ClassFileStream* st, 298 TRAPS) { 299 return parse_stream(class_name, 300 class_loader, 301 protection_domain, 302 st, 303 NULL, // host klass 304 NULL, // cp_patches 305 THREAD); 306 } 307 static InstanceKlass* parse_stream(Symbol* class_name, 308 Handle class_loader, 309 Handle protection_domain, 310 ClassFileStream* st, 311 const InstanceKlass* host_klass, 312 GrowableArray<Handle>* cp_patches, 313 TRAPS); 314 315 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 316 static InstanceKlass* resolve_from_stream(Symbol* class_name, 317 Handle class_loader, 318 Handle protection_domain, 319 ClassFileStream* st, 320 TRAPS); 321 322 // Lookup an already loaded class. If not found NULL is returned. 323 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 324 325 // Lookup an already loaded instance or array class. 326 // Do not make any queries to class loaders; consult only the cache. 327 // If not found NULL is returned. 328 static Klass* find_instance_or_array_klass(Symbol* class_name, 329 Handle class_loader, 330 Handle protection_domain, 331 TRAPS); 332 333 // Lookup an instance or array class that has already been loaded 334 // either into the given class loader, or else into another class 335 // loader that is constrained (via loader constraints) to produce 336 // a consistent class. Do not take protection domains into account. 337 // Do not make any queries to class loaders; consult only the cache. 338 // Return NULL if the class is not found. 339 // 340 // This function is a strict superset of find_instance_or_array_klass. 341 // This function (the unchecked version) makes a conservative prediction 342 // of the result of the checked version, assuming successful lookup. 343 // If both functions return non-null, they must return the same value. 344 // Also, the unchecked version may sometimes be non-null where the 345 // checked version is null. This can occur in several ways: 346 // 1. No query has yet been made to the class loader. 347 // 2. The class loader was queried, but chose not to delegate. 348 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 349 // 4. Loading was attempted, but there was a linkage error of some sort. 350 // In all of these cases, the loader constraints on this type are 351 // satisfied, and it is safe for classes in the given class loader 352 // to manipulate strongly-typed values of the found class, subject 353 // to local linkage and access checks. 354 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 355 Handle class_loader, 356 TRAPS); 357 358 static void classes_do(MetaspaceClosure* it); 359 // Iterate over all methods in all klasses 360 361 static void methods_do(void f(Method*)); 362 363 // Garbage collection support 364 365 // This method applies "blk->do_oop" to all the pointers to "system" 366 // classes and loaders. 367 static void always_strong_oops_do(OopClosure* blk); 368 369 // Unload (that is, break root links to) all unmarked classes and 370 // loaders. Returns "true" iff something was unloaded. 371 static bool do_unloading(BoolObjectClosure* is_alive, 372 GCTimer* gc_timer, 373 bool do_cleaning = true); 374 375 // Used by DumpSharedSpaces only to remove classes that failed verification 376 static void remove_classes_in_error_state(); 377 378 static int calculate_systemdictionary_size(int loadedclasses); 379 380 // Applies "f->do_oop" to all root oops in the system dictionary. 381 static void oops_do(OopClosure* f); 382 static void roots_oops_do(OopClosure* strong, OopClosure* weak); 383 384 // System loader lock 385 static oop system_loader_lock() { return _system_loader_lock_obj; } 386 387 public: 388 // Sharing support. 389 static void reorder_dictionary_for_sharing() NOT_CDS_RETURN; 390 static void combine_shared_dictionaries(); 391 static size_t count_bytes_for_buckets(); 392 static size_t count_bytes_for_table(); 393 static void copy_buckets(char* top, char* end); 394 static void copy_table(char* top, char* end); 395 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 396 int number_of_entries); 397 // Printing 398 static void print() { return print_on(tty); } 399 static void print_on(outputStream* st); 400 static void print_shared(outputStream* st); 401 static void dump(outputStream* st, bool verbose); 402 403 // Monotonically increasing counter which grows as classes are 404 // loaded or modifications such as hot-swapping or setting/removing 405 // of breakpoints are performed 406 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 407 // Needed by evolution and breakpoint code 408 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 409 410 // Verification 411 static void verify(); 412 413 // Initialization 414 static void initialize(TRAPS); 415 416 // Checked fast access to commonly used classes - mostly preloaded 417 static InstanceKlass* check_klass(InstanceKlass* k) { 418 assert(k != NULL, "klass not loaded"); 419 return k; 420 } 421 422 static InstanceKlass* check_klass_Pre(InstanceKlass* k) { return check_klass(k); } 423 static InstanceKlass* check_klass_Opt(InstanceKlass* k) { return k; } 424 425 JVMCI_ONLY(static InstanceKlass* check_klass_Jvmci(InstanceKlass* k) { return k; }) 426 427 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 428 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 429 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 430 int limit = (int)end_id + 1; 431 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 432 } 433 434 public: 435 #define WK_KLASS_DECLARE(name, symbol, option) \ 436 static InstanceKlass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 437 static InstanceKlass** name##_addr() { \ 438 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 439 } 440 WK_KLASSES_DO(WK_KLASS_DECLARE); 441 #undef WK_KLASS_DECLARE 442 443 static InstanceKlass* well_known_klass(WKID id) { 444 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 445 return _well_known_klasses[id]; 446 } 447 448 static InstanceKlass** well_known_klass_addr(WKID id) { 449 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 450 return &_well_known_klasses[id]; 451 } 452 static void well_known_klasses_do(MetaspaceClosure* it); 453 454 // Local definition for direct access to the private array: 455 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 456 457 static InstanceKlass* box_klass(BasicType t) { 458 assert((uint)t < T_VOID+1, "range check"); 459 return check_klass(_box_klasses[t]); 460 } 461 static BasicType box_klass_type(Klass* k); // inverse of box_klass 462 463 // methods returning lazily loaded klasses 464 // The corresponding method to load the class must be called before calling them. 465 static InstanceKlass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 466 467 static void load_abstract_ownable_synchronizer_klass(TRAPS); 468 469 protected: 470 // Returns the class loader data to be used when looking up/updating the 471 // system dictionary. 472 static ClassLoaderData *class_loader_data(Handle class_loader) { 473 return ClassLoaderData::class_loader_data(class_loader()); 474 } 475 476 public: 477 // Tells whether ClassLoader.checkPackageAccess is present 478 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 479 480 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 481 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 482 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 483 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 484 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 485 486 // Returns java system loader 487 static oop java_system_loader(); 488 489 // Returns java platform loader 490 static oop java_platform_loader(); 491 492 // Compute the java system and platform loaders 493 static void compute_java_loaders(TRAPS); 494 495 // Register a new class loader 496 static ClassLoaderData* register_loader(Handle class_loader, TRAPS); 497 protected: 498 // Mirrors for primitive classes (created eagerly) 499 static oop check_mirror(oop m) { 500 assert(m != NULL, "mirror not initialized"); 501 return m; 502 } 503 504 public: 505 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 506 507 // Check class loader constraints 508 static bool add_loader_constraint(Symbol* name, Handle loader1, 509 Handle loader2, TRAPS); 510 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 511 Handle loader2, bool is_method, TRAPS); 512 513 // JSR 292 514 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 515 // (asks Java to compute it if necessary, except in a compiler thread) 516 static methodHandle find_method_handle_invoker(Klass* klass, 517 Symbol* name, 518 Symbol* signature, 519 Klass* accessing_klass, 520 Handle *appendix_result, 521 Handle *method_type_result, 522 TRAPS); 523 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 524 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 525 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 526 Symbol* signature, 527 TRAPS); 528 529 // compute java_mirror (java.lang.Class instance) for a type ("I", "[[B", "LFoo;", etc.) 530 // Either the accessing_klass or the CL/PD can be non-null, but not both. 531 static Handle find_java_mirror_for_type(Symbol* signature, 532 Klass* accessing_klass, 533 Handle class_loader, 534 Handle protection_domain, 535 SignatureStream::FailureMode failure_mode, 536 TRAPS); 537 static Handle find_java_mirror_for_type(Symbol* signature, 538 Klass* accessing_klass, 539 SignatureStream::FailureMode failure_mode, 540 TRAPS) { 541 // callee will fill in CL/PD from AK, if they are needed 542 return find_java_mirror_for_type(signature, accessing_klass, Handle(), Handle(), 543 failure_mode, THREAD); 544 } 545 546 547 // fast short-cut for the one-character case: 548 static oop find_java_mirror_for_type(char signature_char); 549 550 // find a java.lang.invoke.MethodType object for a given signature 551 // (asks Java to compute it if necessary, except in a compiler thread) 552 static Handle find_method_handle_type(Symbol* signature, 553 Klass* accessing_klass, 554 TRAPS); 555 556 // find a java.lang.Class object for a given signature 557 static Handle find_field_handle_type(Symbol* signature, 558 Klass* accessing_klass, 559 TRAPS); 560 561 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 562 static Handle link_method_handle_constant(Klass* caller, 563 int ref_kind, //e.g., JVM_REF_invokeVirtual 564 Klass* callee, 565 Symbol* name, 566 Symbol* signature, 567 TRAPS); 568 569 // ask Java to compute a constant by invoking a BSM given a Dynamic_info CP entry 570 static Handle link_dynamic_constant(Klass* caller, 571 int condy_index, 572 Handle bootstrap_specifier, 573 Symbol* name, 574 Symbol* type, 575 TRAPS); 576 577 // ask Java to create a dynamic call site, while linking an invokedynamic op 578 static methodHandle find_dynamic_call_site_invoker(Klass* caller, 579 int indy_index, 580 Handle bootstrap_method, 581 Symbol* name, 582 Symbol* type, 583 Handle *appendix_result, 584 Handle *method_type_result, 585 TRAPS); 586 587 // Utility for printing loader "name" as part of tracing constraints 588 static const char* loader_name(const oop loader); 589 static const char* loader_name(const ClassLoaderData* loader_data); 590 591 // Record the error when the first attempt to resolve a reference from a constant 592 // pool entry to a class fails. 593 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error, 594 Symbol* message); 595 static void delete_resolution_error(ConstantPool* pool); 596 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which, 597 Symbol** message); 598 599 600 static ProtectionDomainCacheEntry* cache_get(Handle protection_domain); 601 602 protected: 603 604 enum Constants { 605 _loader_constraint_size = 107, // number of entries in constraint table 606 _resolution_error_size = 107, // number of entries in resolution error table 607 _invoke_method_size = 139, // number of entries in invoke method table 608 _shared_dictionary_size = 1009, // number of entries in shared dictionary 609 _placeholder_table_size = 1009 // number of entries in hash table for placeholders 610 }; 611 612 613 // Static tables owned by the SystemDictionary 614 615 // Hashtable holding placeholders for classes being loaded. 616 static PlaceholderTable* _placeholders; 617 618 // Hashtable holding classes from the shared archive. 619 static Dictionary* _shared_dictionary; 620 621 // Monotonically increasing counter which grows with 622 // loading classes as well as hot-swapping and breakpoint setting 623 // and removal. 624 static int _number_of_modifications; 625 626 // Lock object for system class loader 627 static oop _system_loader_lock_obj; 628 629 // Constraints on class loaders 630 static LoaderConstraintTable* _loader_constraints; 631 632 // Resolution errors 633 static ResolutionErrorTable* _resolution_errors; 634 635 // Invoke methods (JSR 292) 636 static SymbolPropertyTable* _invoke_method_table; 637 638 // ProtectionDomain cache 639 static ProtectionDomainCacheTable* _pd_cache_table; 640 641 protected: 642 static void validate_protection_domain(InstanceKlass* klass, 643 Handle class_loader, 644 Handle protection_domain, TRAPS); 645 646 friend class VM_PopulateDumpSharedSpace; 647 friend class TraversePlaceholdersClosure; 648 static Dictionary* shared_dictionary() { return _shared_dictionary; } 649 static PlaceholderTable* placeholders() { return _placeholders; } 650 static LoaderConstraintTable* constraints() { return _loader_constraints; } 651 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 652 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 653 654 // Basic loading operations 655 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 656 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 657 static InstanceKlass* handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 658 // Wait on SystemDictionary_lock; unlocks lockObject before 659 // waiting; relocks lockObject with correct recursion count 660 // after waiting, but before reentering SystemDictionary_lock 661 // to preserve lock order semantics. 662 static void double_lock_wait(Handle lockObject, TRAPS); 663 static void define_instance_class(InstanceKlass* k, TRAPS); 664 static InstanceKlass* find_or_define_instance_class(Symbol* class_name, 665 Handle class_loader, 666 InstanceKlass* k, TRAPS); 667 static bool is_shared_class_visible(Symbol* class_name, InstanceKlass* ik, 668 Handle class_loader, TRAPS); 669 static InstanceKlass* load_shared_class(InstanceKlass* ik, 670 Handle class_loader, 671 Handle protection_domain, 672 TRAPS); 673 static InstanceKlass* load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 674 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 675 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 676 static bool is_parallelCapable(Handle class_loader); 677 static bool is_parallelDefine(Handle class_loader); 678 679 public: 680 static InstanceKlass* load_shared_class(Symbol* class_name, 681 Handle class_loader, 682 TRAPS); 683 static bool is_system_class_loader(oop class_loader); 684 static bool is_platform_class_loader(oop class_loader); 685 static void clear_invoke_method_table(); 686 687 // Returns TRUE if the method is a non-public member of class java.lang.Object. 688 static bool is_nonpublic_Object_method(Method* m) { 689 assert(m != NULL, "Unexpected NULL Method*"); 690 return !m->is_public() && m->method_holder() == SystemDictionary::Object_klass(); 691 } 692 693 protected: 694 static InstanceKlass* find_shared_class(Symbol* class_name); 695 696 // Setup link to hierarchy 697 static void add_to_hierarchy(InstanceKlass* k, TRAPS); 698 699 // Basic find on loaded classes 700 static InstanceKlass* find_class(unsigned int hash, 701 Symbol* name, Dictionary* dictionary); 702 static InstanceKlass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 703 704 // Basic find on classes in the midst of being loaded 705 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 706 707 // Add a placeholder for a class being loaded 708 static void add_placeholder(int index, 709 Symbol* class_name, 710 ClassLoaderData* loader_data); 711 static void remove_placeholder(int index, 712 Symbol* class_name, 713 ClassLoaderData* loader_data); 714 715 // Performs cleanups after resolve_super_or_fail. This typically needs 716 // to be called on failure. 717 // Won't throw, but can block. 718 static void resolution_cleanups(Symbol* class_name, 719 ClassLoaderData* loader_data, 720 TRAPS); 721 722 // Initialization 723 static void initialize_preloaded_classes(TRAPS); 724 725 // Class loader constraints 726 static void check_constraints(unsigned int hash, 727 InstanceKlass* k, Handle loader, 728 bool defining, TRAPS); 729 static void update_dictionary(unsigned int d_hash, 730 int p_index, unsigned int p_hash, 731 InstanceKlass* k, Handle loader, 732 TRAPS); 733 734 // Variables holding commonly used klasses (preloaded) 735 static InstanceKlass* _well_known_klasses[]; 736 737 // Lazily loaded klasses 738 static InstanceKlass* volatile _abstract_ownable_synchronizer_klass; 739 740 // table of box klasses (int_klass, etc.) 741 static InstanceKlass* _box_klasses[T_VOID+1]; 742 743 static oop _java_system_loader; 744 static oop _java_platform_loader; 745 746 static bool _has_checkPackageAccess; 747 }; 748 749 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP