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 #include "jvmci/systemDictionary_jvmci.hpp" 37 38 39 // The system dictionary stores all loaded classes and maps: 40 // 41 // [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass* 42 // 43 // Classes are loaded lazily. The default VM class loader is 44 // represented as NULL. 45 46 // The underlying data structure is an open hash table with a fixed number 47 // of buckets. During loading the loader object is locked, (for the VM loader 48 // a private lock object is used). Class loading can thus be done concurrently, 49 // but only by different loaders. 50 // 51 // During loading a placeholder (name, loader) is temporarily placed in 52 // a side data structure, and is used to detect ClassCircularityErrors 53 // and to perform verification during GC. A GC can occur in the midst 54 // of class loading, as we call out to Java, have to take locks, etc. 55 // 56 // When class loading is finished, a new entry is added to the system 57 // dictionary and the place holder is removed. Note that the protection 58 // domain field of the system dictionary has not yet been filled in when 59 // the "real" system dictionary entry is created. 60 // 61 // Clients of this class who are interested in finding if a class has 62 // been completely loaded -- not classes in the process of being loaded -- 63 // can read the SystemDictionary unlocked. This is safe because 64 // - entries are only deleted at safepoints 65 // - readers cannot come to a safepoint while actively examining 66 // an entry (an entry cannot be deleted from under a reader) 67 // - entries must be fully formed before they are available to concurrent 68 // readers (we must ensure write ordering) 69 // 70 // Note that placeholders are deleted at any time, as they are removed 71 // when a class is completely loaded. Therefore, readers as well as writers 72 // of placeholders must hold the SystemDictionary_lock. 73 // 74 75 class Dictionary; 76 class PlaceholderTable; 77 class LoaderConstraintTable; 78 template <MEMFLAGS F> class HashtableBucket; 79 class ResolutionErrorTable; 80 class SymbolPropertyTable; 81 class Ticks; 82 83 // Certain classes are preloaded, such as java.lang.Object and java.lang.String. 84 // They are all "well-known", in the sense that no class loader is allowed 85 // to provide a different definition. 86 // 87 // These klasses must all have names defined in vmSymbols. 88 89 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 90 91 // Each well-known class has a short klass name (like object_klass), 92 // a vmSymbol name (like java_lang_Object), and a flag word 93 // that makes some minor distinctions, like whether the klass 94 // is preloaded, optional, release-specific, etc. 95 // The order of these definitions is significant; it is the order in which 96 // preloading is actually performed by initialize_preloaded_classes. 97 98 #define WK_KLASSES_DO(do_klass) \ 99 /* well-known classes */ \ 100 do_klass(Object_klass, java_lang_Object, Pre ) \ 101 do_klass(String_klass, java_lang_String, Pre ) \ 102 do_klass(Class_klass, java_lang_Class, Pre ) \ 103 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \ 104 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \ 105 do_klass(Serializable_klass, java_io_Serializable, Pre ) \ 106 do_klass(System_klass, java_lang_System, Pre ) \ 107 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \ 108 do_klass(Error_klass, java_lang_Error, Pre ) \ 109 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \ 110 do_klass(Exception_klass, java_lang_Exception, Pre ) \ 111 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \ 112 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \ 113 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \ 114 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \ 115 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \ 116 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \ 117 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \ 118 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \ 119 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \ 120 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \ 121 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \ 122 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \ 123 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \ 124 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \ 125 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \ 126 \ 127 /* Preload ref klasses and set reference types */ \ 128 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \ 129 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \ 130 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \ 131 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \ 132 do_klass(Cleaner_klass, sun_misc_Cleaner, Pre ) \ 133 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \ 134 \ 135 do_klass(Thread_klass, java_lang_Thread, Pre ) \ 136 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \ 137 do_klass(Properties_klass, java_util_Properties, Pre ) \ 138 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \ 139 do_klass(reflect_Field_klass, java_lang_reflect_Field, 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(URLClassLoader_klass, java_net_URLClassLoader, Pre ) \ 177 do_klass(URL_klass, java_net_URL, Pre ) \ 178 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \ 179 do_klass(sun_misc_Launcher_klass, sun_misc_Launcher, Pre ) \ 180 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \ 181 \ 182 /* It's NULL in non-1.4 JDKs. */ \ 183 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 184 /* 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 \ 197 /* JVMCI classes. These are loaded on-demand. */ \ 198 JVMCI_WK_KLASSES_DO(do_klass) \ 199 200 /*end*/ 201 202 203 class SystemDictionary : AllStatic { 204 friend class VMStructs; 205 friend class SystemDictionaryHandles; 206 207 public: 208 enum WKID { 209 NO_WKID = 0, 210 211 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 212 WK_KLASSES_DO(WK_KLASS_ENUM) 213 #undef WK_KLASS_ENUM 214 215 WKID_LIMIT, 216 217 #if INCLUDE_JVMCI 218 FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(HotSpotCompiledCode_klass), 219 LAST_JVMCI_WKID = WK_KLASS_ENUM_NAME(Value_klass), 220 #endif 221 222 FIRST_WKID = NO_WKID + 1 223 }; 224 225 enum InitOption { 226 Pre, // preloaded; error if not present 227 228 // Order is significant. Options before this point require resolve_or_fail. 229 // Options after this point will use resolve_or_null instead. 230 231 Opt, // preload tried; NULL if not present 232 #if INCLUDE_JVMCI 233 Jvmci, // preload tried; error if not present, use only with JVMCI 234 #endif 235 OPTION_LIMIT, 236 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 237 }; 238 239 240 // Returns a class with a given class name and class loader. Loads the 241 // class if needed. If not found a NoClassDefFoundError or a 242 // ClassNotFoundException is thrown, depending on the value on the 243 // throw_error flag. For most uses the throw_error argument should be set 244 // to true. 245 246 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 247 // Convenient call for null loader and protection domain. 248 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 249 protected: 250 // handle error translation for resolve_or_null results 251 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, KlassHandle klass_h, TRAPS); 252 253 public: 254 255 // Returns a class with a given class name and class loader. 256 // Loads the class if needed. If not found NULL is returned. 257 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 258 // Version with null loader and protection domain 259 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 260 261 // Resolve a superclass or superinterface. Called from ClassFileParser, 262 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 263 // "child_name" is the class whose super class or interface is being resolved. 264 static Klass* resolve_super_or_fail(Symbol* child_name, 265 Symbol* class_name, 266 Handle class_loader, 267 Handle protection_domain, 268 bool is_superclass, 269 TRAPS); 270 271 // Parse new stream. This won't update the system dictionary or 272 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 273 static Klass* parse_stream(Symbol* class_name, 274 Handle class_loader, 275 Handle protection_domain, 276 ClassFileStream* st, 277 TRAPS) { 278 KlassHandle nullHandle; 279 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD); 280 } 281 static Klass* parse_stream(Symbol* class_name, 282 Handle class_loader, 283 Handle protection_domain, 284 ClassFileStream* st, 285 KlassHandle host_klass, 286 GrowableArray<Handle>* cp_patches, 287 TRAPS); 288 289 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 290 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader, 291 Handle protection_domain, 292 ClassFileStream* st, bool verify, TRAPS); 293 294 // Lookup an already loaded class. If not found NULL is returned. 295 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 296 297 // Lookup an already loaded instance or array class. 298 // Do not make any queries to class loaders; consult only the cache. 299 // If not found NULL is returned. 300 static Klass* find_instance_or_array_klass(Symbol* class_name, 301 Handle class_loader, 302 Handle protection_domain, 303 TRAPS); 304 305 // Lookup an instance or array class that has already been loaded 306 // either into the given class loader, or else into another class 307 // loader that is constrained (via loader constraints) to produce 308 // a consistent class. Do not take protection domains into account. 309 // Do not make any queries to class loaders; consult only the cache. 310 // Return NULL if the class is not found. 311 // 312 // This function is a strict superset of find_instance_or_array_klass. 313 // This function (the unchecked version) makes a conservative prediction 314 // of the result of the checked version, assuming successful lookup. 315 // If both functions return non-null, they must return the same value. 316 // Also, the unchecked version may sometimes be non-null where the 317 // checked version is null. This can occur in several ways: 318 // 1. No query has yet been made to the class loader. 319 // 2. The class loader was queried, but chose not to delegate. 320 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 321 // 4. Loading was attempted, but there was a linkage error of some sort. 322 // In all of these cases, the loader constraints on this type are 323 // satisfied, and it is safe for classes in the given class loader 324 // to manipulate strongly-typed values of the found class, subject 325 // to local linkage and access checks. 326 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 327 Handle class_loader, 328 TRAPS); 329 330 // Iterate over all klasses in dictionary 331 // Just the classes from defining class loaders 332 static void classes_do(void f(Klass*)); 333 // Added for initialize_itable_for_klass to handle exceptions 334 static void classes_do(void f(Klass*, TRAPS), TRAPS); 335 // All classes, and their class loaders 336 static void classes_do(void f(Klass*, ClassLoaderData*)); 337 338 static void placeholders_do(void f(Symbol*)); 339 340 // Iterate over all methods in all klasses in dictionary 341 static void methods_do(void f(Method*)); 342 343 // Garbage collection support 344 345 // This method applies "blk->do_oop" to all the pointers to "system" 346 // classes and loaders. 347 static void always_strong_oops_do(OopClosure* blk); 348 static void always_strong_classes_do(KlassClosure* closure); 349 350 // Unload (that is, break root links to) all unmarked classes and 351 // loaders. Returns "true" iff something was unloaded. 352 static bool do_unloading(BoolObjectClosure* is_alive, 353 bool clean_previous_versions = true); 354 355 // Used by DumpSharedSpaces only to remove classes that failed verification 356 static void remove_classes_in_error_state(); 357 358 static int calculate_systemdictionary_size(int loadedclasses); 359 360 // Applies "f->do_oop" to all root oops in the system dictionary. 361 static void oops_do(OopClosure* f); 362 static void roots_oops_do(OopClosure* strong, OopClosure* weak); 363 364 // System loader lock 365 static oop system_loader_lock() { return _system_loader_lock_obj; } 366 367 protected: 368 // Extended Redefine classes support (tbi) 369 static void preloaded_classes_do(KlassClosure* f); 370 static void lazily_loaded_classes_do(KlassClosure* f); 371 public: 372 // Sharing support. 373 static void reorder_dictionary(); 374 static void copy_buckets(char** top, char* end); 375 static void copy_table(char** top, char* end); 376 static void reverse(); 377 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 378 int number_of_entries); 379 // Printing 380 static void print(bool details = true); 381 static void print_shared(bool details = true); 382 383 // Number of contained klasses 384 // This is both fully loaded classes and classes in the process 385 // of being loaded 386 static int number_of_classes(); 387 388 // Monotonically increasing counter which grows as classes are 389 // loaded or modifications such as hot-swapping or setting/removing 390 // of breakpoints are performed 391 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 392 // Needed by evolution and breakpoint code 393 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 394 395 // Verification 396 static void verify(); 397 398 #ifdef ASSERT 399 static bool is_internal_format(Symbol* class_name); 400 #endif 401 402 // Initialization 403 static void initialize(TRAPS); 404 405 // Fast access to commonly used classes (preloaded) 406 static Klass* check_klass(Klass* k) { 407 assert(k != NULL, "preloaded klass not initialized"); 408 return k; 409 } 410 411 static Klass* check_klass_Pre( Klass* k) { return check_klass(k); } 412 static Klass* check_klass_Opt( Klass* k) { return k; } 413 414 JVMCI_ONLY(static Klass* check_klass_Jvmci(Klass* k) { return k; }) 415 416 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 417 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 418 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 419 int limit = (int)end_id + 1; 420 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 421 } 422 423 public: 424 #define WK_KLASS_DECLARE(name, symbol, option) \ 425 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 426 static Klass** name##_addr() { \ 427 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 428 } 429 WK_KLASSES_DO(WK_KLASS_DECLARE); 430 #undef WK_KLASS_DECLARE 431 432 static Klass* well_known_klass(WKID id) { 433 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 434 return _well_known_klasses[id]; 435 } 436 437 static Klass** well_known_klass_addr(WKID id) { 438 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 439 return &_well_known_klasses[id]; 440 } 441 442 // Local definition for direct access to the private array: 443 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 444 445 static Klass* box_klass(BasicType t) { 446 assert((uint)t < T_VOID+1, "range check"); 447 return check_klass(_box_klasses[t]); 448 } 449 static BasicType box_klass_type(Klass* k); // inverse of box_klass 450 451 // methods returning lazily loaded klasses 452 // The corresponding method to load the class must be called before calling them. 453 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 454 455 static void load_abstract_ownable_synchronizer_klass(TRAPS); 456 457 protected: 458 // Tells whether ClassLoader.loadClassInternal is present 459 static bool has_loadClassInternal() { return _has_loadClassInternal; } 460 461 // Returns the class loader data to be used when looking up/updating the 462 // system dictionary. 463 static ClassLoaderData *class_loader_data(Handle class_loader) { 464 return ClassLoaderData::class_loader_data(class_loader()); 465 } 466 467 public: 468 // Tells whether ClassLoader.checkPackageAccess is present 469 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 470 471 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 472 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 473 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 474 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 475 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 476 477 // Returns default system loader 478 static oop java_system_loader(); 479 480 // Compute the default system loader 481 static void compute_java_system_loader(TRAPS); 482 483 // Register a new class loader 484 static ClassLoaderData* register_loader(Handle class_loader, TRAPS); 485 protected: 486 // Mirrors for primitive classes (created eagerly) 487 static oop check_mirror(oop m) { 488 assert(m != NULL, "mirror not initialized"); 489 return m; 490 } 491 492 public: 493 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 494 495 // Check class loader constraints 496 static bool add_loader_constraint(Symbol* name, Handle loader1, 497 Handle loader2, TRAPS); 498 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 499 Handle loader2, bool is_method, TRAPS); 500 501 // JSR 292 502 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 503 // (asks Java to compute it if necessary, except in a compiler thread) 504 static methodHandle find_method_handle_invoker(Symbol* name, 505 Symbol* signature, 506 KlassHandle 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 KlassHandle 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(KlassHandle caller, 523 int ref_kind, //e.g., JVM_REF_invokeVirtual 524 KlassHandle 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(KlassHandle 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(oop loader) { 540 return ((loader) == NULL ? "<bootloader>" : 541 InstanceKlass::cast((loader)->klass())->name()->as_C_string() ); 542 } 543 static const char* loader_name(ClassLoaderData* loader_data) { 544 return (loader_data->class_loader() == NULL ? "<bootloader>" : 545 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() ); 546 } 547 548 // Record the error when the first attempt to resolve a reference from a constant 549 // pool entry to a class fails. 550 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error, 551 Symbol* message); 552 static void delete_resolution_error(ConstantPool* pool); 553 static Symbol* find_resolution_error(constantPoolHandle pool, int which, 554 Symbol** message); 555 556 protected: 557 558 enum Constants { 559 _loader_constraint_size = 107, // number of entries in constraint table 560 _resolution_error_size = 107, // number of entries in resolution error table 561 _invoke_method_size = 139, // number of entries in invoke method table 562 _nof_buckets = 1009, // number of buckets in hash table for placeholders 563 _old_default_sdsize = 1009, // backward compat for system dictionary size 564 _prime_array_size = 8, // array of primes for system dictionary size 565 _average_depth_goal = 3 // goal for lookup length 566 }; 567 568 569 // Static variables 570 571 // hashtable sizes for system dictionary to allow growth 572 // prime numbers for system dictionary size 573 static int _sdgeneration; 574 static const int _primelist[_prime_array_size]; 575 576 // Hashtable holding loaded classes. 577 static Dictionary* _dictionary; 578 579 // Hashtable holding placeholders for classes being loaded. 580 static PlaceholderTable* _placeholders; 581 582 // Hashtable holding classes from the shared archive. 583 static Dictionary* _shared_dictionary; 584 585 // Monotonically increasing counter which grows with 586 // _number_of_classes as well as hot-swapping and breakpoint setting 587 // and removal. 588 static int _number_of_modifications; 589 590 // Lock object for system class loader 591 static oop _system_loader_lock_obj; 592 593 // Constraints on class loaders 594 static LoaderConstraintTable* _loader_constraints; 595 596 // Resolution errors 597 static ResolutionErrorTable* _resolution_errors; 598 599 // Invoke methods (JSR 292) 600 static SymbolPropertyTable* _invoke_method_table; 601 602 public: 603 // for VM_CounterDecay iteration support 604 friend class CounterDecay; 605 static Klass* try_get_next_class(); 606 607 protected: 608 static void validate_protection_domain(instanceKlassHandle klass, 609 Handle class_loader, 610 Handle protection_domain, TRAPS); 611 612 friend class VM_PopulateDumpSharedSpace; 613 friend class TraversePlaceholdersClosure; 614 static Dictionary* dictionary() { return _dictionary; } 615 static Dictionary* shared_dictionary() { return _shared_dictionary; } 616 static PlaceholderTable* placeholders() { return _placeholders; } 617 static LoaderConstraintTable* constraints() { return _loader_constraints; } 618 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 619 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 620 621 // Basic loading operations 622 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 623 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 624 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 625 // Wait on SystemDictionary_lock; unlocks lockObject before 626 // waiting; relocks lockObject with correct recursion count 627 // after waiting, but before reentering SystemDictionary_lock 628 // to preserve lock order semantics. 629 static void double_lock_wait(Handle lockObject, TRAPS); 630 static void define_instance_class(instanceKlassHandle k, TRAPS); 631 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name, 632 Handle class_loader, 633 instanceKlassHandle k, TRAPS); 634 static instanceKlassHandle load_shared_class(instanceKlassHandle ik, 635 Handle class_loader, 636 Handle protection_domain, 637 TRAPS); 638 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 639 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 640 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 641 static bool is_parallelCapable(Handle class_loader); 642 static bool is_parallelDefine(Handle class_loader); 643 644 public: 645 static instanceKlassHandle load_shared_class(Symbol* class_name, 646 Handle class_loader, 647 TRAPS); 648 static bool is_ext_class_loader(Handle class_loader); 649 650 protected: 651 static Klass* find_shared_class(Symbol* class_name); 652 653 // Setup link to hierarchy 654 static void add_to_hierarchy(instanceKlassHandle k, TRAPS); 655 656 // event based tracing 657 static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k, 658 Handle initiating_loader); 659 // We pass in the hashtable index so we can calculate it outside of 660 // the SystemDictionary_lock. 661 662 // Basic find on loaded classes 663 static Klass* find_class(int index, unsigned int hash, 664 Symbol* name, ClassLoaderData* loader_data); 665 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 666 667 // Basic find on classes in the midst of being loaded 668 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 669 670 // Updating entry in dictionary 671 // Add a completely loaded class 672 static void add_klass(int index, Symbol* class_name, 673 ClassLoaderData* loader_data, KlassHandle obj); 674 675 // Add a placeholder for a class being loaded 676 static void add_placeholder(int index, 677 Symbol* class_name, 678 ClassLoaderData* loader_data); 679 static void remove_placeholder(int index, 680 Symbol* class_name, 681 ClassLoaderData* loader_data); 682 683 // Performs cleanups after resolve_super_or_fail. This typically needs 684 // to be called on failure. 685 // Won't throw, but can block. 686 static void resolution_cleanups(Symbol* class_name, 687 ClassLoaderData* loader_data, 688 TRAPS); 689 690 // Initialization 691 static void initialize_preloaded_classes(TRAPS); 692 693 // Class loader constraints 694 static void check_constraints(int index, unsigned int hash, 695 instanceKlassHandle k, Handle loader, 696 bool defining, TRAPS); 697 static void update_dictionary(int d_index, unsigned int d_hash, 698 int p_index, unsigned int p_hash, 699 instanceKlassHandle k, Handle loader, 700 TRAPS); 701 702 // Variables holding commonly used klasses (preloaded) 703 static Klass* _well_known_klasses[]; 704 705 // Lazily loaded klasses 706 static Klass* volatile _abstract_ownable_synchronizer_klass; 707 708 // table of box klasses (int_klass, etc.) 709 static Klass* _box_klasses[T_VOID+1]; 710 711 static oop _java_system_loader; 712 713 static bool _has_loadClassInternal; 714 static bool _has_checkPackageAccess; 715 }; 716 717 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP