1 /* 2 * Copyright (c) 1997, 2013, 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 "trace/traceTime.hpp" 35 #include "utilities/hashtable.hpp" 36 #include "utilities/hashtable.inline.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 82 // Certain classes are preloaded, such as java.lang.Object and java.lang.String. 83 // They are all "well-known", in the sense that no class loader is allowed 84 // to provide a different definition. 85 // 86 // These klasses must all have names defined in vmSymbols. 87 88 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 89 90 // Each well-known class has a short klass name (like object_klass), 91 // a vmSymbol name (like java_lang_Object), and a flag word 92 // that makes some minor distinctions, like whether the klass 93 // is preloaded, optional, release-specific, etc. 94 // The order of these definitions is significant; it is the order in which 95 // preloading is actually performed by initialize_preloaded_classes. 96 97 #define WK_KLASSES_DO(do_klass) \ 98 /* well-known classes */ \ 99 do_klass(Object_klass, java_lang_Object, Pre ) \ 100 do_klass(String_klass, java_lang_String, Pre ) \ 101 do_klass(Class_klass, java_lang_Class, Pre ) \ 102 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \ 103 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \ 104 do_klass(Serializable_klass, java_io_Serializable, Pre ) \ 105 do_klass(System_klass, java_lang_System, Pre ) \ 106 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \ 107 do_klass(Error_klass, java_lang_Error, Pre ) \ 108 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \ 109 do_klass(Exception_klass, java_lang_Exception, Pre ) \ 110 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \ 111 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \ 112 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \ 113 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \ 114 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \ 115 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \ 116 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \ 117 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \ 118 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \ 119 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \ 120 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \ 121 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \ 122 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \ 123 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \ 124 \ 125 /* Preload ref klasses and set reference types */ \ 126 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \ 127 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \ 128 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \ 129 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \ 130 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \ 131 \ 132 do_klass(Thread_klass, java_lang_Thread, Pre ) \ 133 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \ 134 do_klass(Properties_klass, java_util_Properties, Pre ) \ 135 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \ 136 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \ 137 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \ 138 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \ 139 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \ 140 \ 141 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 142 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \ 143 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 144 do_klass(lambda_MagicLambdaImpl_klass, java_lang_invoke_MagicLambdaImpl, Opt ) \ 145 do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \ 146 do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Opt_Only_JDK14NewRef) \ 147 do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Opt_Only_JDK14NewRef) \ 148 do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \ 149 do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt_Only_JDK15 ) \ 150 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15 ) \ 151 do_klass(reflect_CallerSensitive_klass, sun_reflect_CallerSensitive, Opt ) \ 152 \ 153 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 154 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre_JSR292 ) \ 155 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre_JSR292 ) \ 156 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre_JSR292 ) \ 157 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \ 158 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre_JSR292 ) \ 159 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre_JSR292 ) \ 160 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre_JSR292 ) \ 161 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre_JSR292 ) \ 162 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre_JSR292 ) \ 163 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre_JSR292 ) \ 164 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 165 \ 166 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \ 167 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \ 168 \ 169 /* It's NULL in non-1.4 JDKs. */ \ 170 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 171 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \ 172 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 173 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \ 174 \ 175 do_klass(PostVMInitHook_klass, sun_misc_PostVMInitHook, Opt ) \ 176 \ 177 /* Preload boxing klasses */ \ 178 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \ 179 do_klass(Character_klass, java_lang_Character, Pre ) \ 180 do_klass(Float_klass, java_lang_Float, Pre ) \ 181 do_klass(Double_klass, java_lang_Double, Pre ) \ 182 do_klass(Byte_klass, java_lang_Byte, Pre ) \ 183 do_klass(Short_klass, java_lang_Short, Pre ) \ 184 do_klass(Integer_klass, java_lang_Integer, Pre ) \ 185 do_klass(Long_klass, java_lang_Long, Pre ) \ 186 /*end*/ 187 188 189 class SystemDictionary : AllStatic { 190 friend class VMStructs; 191 friend class SystemDictionaryHandles; 192 193 public: 194 enum WKID { 195 NO_WKID = 0, 196 197 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 198 WK_KLASSES_DO(WK_KLASS_ENUM) 199 #undef WK_KLASS_ENUM 200 201 WKID_LIMIT, 202 203 FIRST_WKID = NO_WKID + 1 204 }; 205 206 enum InitOption { 207 Pre, // preloaded; error if not present 208 Pre_JSR292, // preloaded if EnableInvokeDynamic 209 210 // Order is significant. Options before this point require resolve_or_fail. 211 // Options after this point will use resolve_or_null instead. 212 213 Opt, // preload tried; NULL if not present 214 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection 215 Opt_Only_JDK15, // preload tried; use only with JDK1.5+ 216 OPTION_LIMIT, 217 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 218 }; 219 220 221 // Returns a class with a given class name and class loader. Loads the 222 // class if needed. If not found a NoClassDefFoundError or a 223 // ClassNotFoundException is thrown, depending on the value on the 224 // throw_error flag. For most uses the throw_error argument should be set 225 // to true. 226 227 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 228 // Convenient call for null loader and protection domain. 229 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 230 private: 231 // handle error translation for resolve_or_null results 232 static Klass* handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS); 233 234 public: 235 236 // Returns a class with a given class name and class loader. 237 // Loads the class if needed. If not found NULL is returned. 238 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 239 // Version with null loader and protection domain 240 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 241 242 // Resolve a superclass or superinterface. Called from ClassFileParser, 243 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 244 // "child_name" is the class whose super class or interface is being resolved. 245 static Klass* resolve_super_or_fail(Symbol* child_name, 246 Symbol* class_name, 247 Handle class_loader, 248 Handle protection_domain, 249 bool is_superclass, 250 TRAPS); 251 252 // Parse new stream. This won't update the system dictionary or 253 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 254 static Klass* parse_stream(Symbol* class_name, 255 Handle class_loader, 256 Handle protection_domain, 257 ClassFileStream* st, 258 TRAPS) { 259 KlassHandle nullHandle; 260 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD); 261 } 262 static Klass* parse_stream(Symbol* class_name, 263 Handle class_loader, 264 Handle protection_domain, 265 ClassFileStream* st, 266 KlassHandle host_klass, 267 GrowableArray<Handle>* cp_patches, 268 TRAPS); 269 270 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 271 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader, 272 Handle protection_domain, 273 ClassFileStream* st, bool verify, TRAPS); 274 275 // Lookup an already loaded class. If not found NULL is returned. 276 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 277 278 // Lookup an already loaded instance or array class. 279 // Do not make any queries to class loaders; consult only the cache. 280 // If not found NULL is returned. 281 static Klass* find_instance_or_array_klass(Symbol* class_name, 282 Handle class_loader, 283 Handle protection_domain, 284 TRAPS); 285 286 // Lookup an instance or array class that has already been loaded 287 // either into the given class loader, or else into another class 288 // loader that is constrained (via loader constraints) to produce 289 // a consistent class. Do not take protection domains into account. 290 // Do not make any queries to class loaders; consult only the cache. 291 // Return NULL if the class is not found. 292 // 293 // This function is a strict superset of find_instance_or_array_klass. 294 // This function (the unchecked version) makes a conservative prediction 295 // of the result of the checked version, assuming successful lookup. 296 // If both functions return non-null, they must return the same value. 297 // Also, the unchecked version may sometimes be non-null where the 298 // checked version is null. This can occur in several ways: 299 // 1. No query has yet been made to the class loader. 300 // 2. The class loader was queried, but chose not to delegate. 301 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 302 // 4. Loading was attempted, but there was a linkage error of some sort. 303 // In all of these cases, the loader constraints on this type are 304 // satisfied, and it is safe for classes in the given class loader 305 // to manipulate strongly-typed values of the found class, subject 306 // to local linkage and access checks. 307 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 308 Handle class_loader, 309 TRAPS); 310 311 // Iterate over all klasses in dictionary 312 // Just the classes from defining class loaders 313 static void classes_do(void f(Klass*)); 314 // Added for initialize_itable_for_klass to handle exceptions 315 static void classes_do(void f(Klass*, TRAPS), TRAPS); 316 // All classes, and their class loaders 317 static void classes_do(void f(Klass*, ClassLoaderData*)); 318 319 static void placeholders_do(void f(Symbol*)); 320 321 // Iterate over all methods in all klasses in dictionary 322 static void methods_do(void f(Method*)); 323 324 // Garbage collection support 325 326 // This method applies "blk->do_oop" to all the pointers to "system" 327 // classes and loaders. 328 static void always_strong_oops_do(OopClosure* blk); 329 static void always_strong_classes_do(KlassClosure* closure); 330 331 // Unload (that is, break root links to) all unmarked classes and 332 // loaders. Returns "true" iff something was unloaded. 333 static bool do_unloading(BoolObjectClosure* is_alive); 334 335 static int calculate_systemdictionary_size(int loadedclasses); 336 337 // Applies "f->do_oop" to all root oops in the system dictionary. 338 static void oops_do(OopClosure* f); 339 340 // System loader lock 341 static oop system_loader_lock() { return _system_loader_lock_obj; } 342 343 private: 344 // Extended Redefine classes support (tbi) 345 static void preloaded_classes_do(KlassClosure* f); 346 static void lazily_loaded_classes_do(KlassClosure* f); 347 public: 348 // Sharing support. 349 static void reorder_dictionary(); 350 static void copy_buckets(char** top, char* end); 351 static void copy_table(char** top, char* end); 352 static void reverse(); 353 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 354 int number_of_entries); 355 // Printing 356 static void print() PRODUCT_RETURN; 357 static void print_class_statistics() PRODUCT_RETURN; 358 static void print_method_statistics() PRODUCT_RETURN; 359 360 // Number of contained klasses 361 // This is both fully loaded classes and classes in the process 362 // of being loaded 363 static int number_of_classes(); 364 365 // Monotonically increasing counter which grows as classes are 366 // loaded or modifications such as hot-swapping or setting/removing 367 // of breakpoints are performed 368 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 369 // Needed by evolution and breakpoint code 370 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 371 372 // Verification 373 static void verify(); 374 375 #ifdef ASSERT 376 static bool is_internal_format(Symbol* class_name); 377 #endif 378 379 // Verify class is in dictionary 380 static void verify_obj_klass_present(Symbol* class_name, 381 ClassLoaderData* loader_data); 382 383 // Initialization 384 static void initialize(TRAPS); 385 386 // Fast access to commonly used classes (preloaded) 387 static Klass* check_klass(Klass* k) { 388 assert(k != NULL, "preloaded klass not initialized"); 389 return k; 390 } 391 392 static Klass* check_klass_Pre( Klass* k) { return check_klass(k); } 393 static Klass* check_klass_Pre_JSR292(Klass* k) { return EnableInvokeDynamic ? check_klass(k) : k; } 394 static Klass* check_klass_Opt( Klass* k) { return k; } 395 static Klass* check_klass_Opt_Only_JDK15(Klass* k) { 396 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only"); 397 return k; 398 } 399 static Klass* check_klass_Opt_Only_JDK14NewRef(Klass* k) { 400 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only"); 401 // despite the optional loading, if you use this it must be present: 402 return check_klass(k); 403 } 404 405 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 406 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 407 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 408 int limit = (int)end_id + 1; 409 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 410 } 411 412 public: 413 #define WK_KLASS_DECLARE(name, symbol, option) \ 414 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 415 static Klass** name##_addr() { \ 416 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 417 } 418 WK_KLASSES_DO(WK_KLASS_DECLARE); 419 #undef WK_KLASS_DECLARE 420 421 static Klass* well_known_klass(WKID id) { 422 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 423 return _well_known_klasses[id]; 424 } 425 426 static Klass** well_known_klass_addr(WKID id) { 427 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 428 return &_well_known_klasses[id]; 429 } 430 431 // Local definition for direct access to the private array: 432 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 433 434 static Klass* box_klass(BasicType t) { 435 assert((uint)t < T_VOID+1, "range check"); 436 return check_klass(_box_klasses[t]); 437 } 438 static BasicType box_klass_type(Klass* k); // inverse of box_klass 439 440 // methods returning lazily loaded klasses 441 // The corresponding method to load the class must be called before calling them. 442 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 443 444 static void load_abstract_ownable_synchronizer_klass(TRAPS); 445 446 private: 447 // Tells whether ClassLoader.loadClassInternal is present 448 static bool has_loadClassInternal() { return _has_loadClassInternal; } 449 450 // Returns the class loader data to be used when looking up/updating the 451 // system dictionary. 452 static ClassLoaderData *class_loader_data(Handle class_loader) { 453 return ClassLoaderData::class_loader_data(class_loader()); 454 } 455 456 public: 457 // Tells whether ClassLoader.checkPackageAccess is present 458 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 459 460 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 461 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 462 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 463 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 464 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 465 466 // Returns default system loader 467 static oop java_system_loader(); 468 469 // Compute the default system loader 470 static void compute_java_system_loader(TRAPS); 471 472 // Register a new class loader 473 static ClassLoaderData* register_loader(Handle class_loader, TRAPS); 474 private: 475 // Mirrors for primitive classes (created eagerly) 476 static oop check_mirror(oop m) { 477 assert(m != NULL, "mirror not initialized"); 478 return m; 479 } 480 481 public: 482 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 483 484 // Check class loader constraints 485 static bool add_loader_constraint(Symbol* name, Handle loader1, 486 Handle loader2, TRAPS); 487 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 488 Handle loader2, bool is_method, TRAPS); 489 490 // JSR 292 491 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 492 // (asks Java to compute it if necessary, except in a compiler thread) 493 static methodHandle find_method_handle_invoker(Symbol* name, 494 Symbol* signature, 495 KlassHandle accessing_klass, 496 Handle *appendix_result, 497 Handle *method_type_result, 498 TRAPS); 499 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 500 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 501 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 502 Symbol* signature, 503 TRAPS); 504 // find a java.lang.invoke.MethodType object for a given signature 505 // (asks Java to compute it if necessary, except in a compiler thread) 506 static Handle find_method_handle_type(Symbol* signature, 507 KlassHandle accessing_klass, 508 TRAPS); 509 510 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 511 static Handle link_method_handle_constant(KlassHandle caller, 512 int ref_kind, //e.g., JVM_REF_invokeVirtual 513 KlassHandle callee, 514 Symbol* name, 515 Symbol* signature, 516 TRAPS); 517 518 // ask Java to create a dynamic call site, while linking an invokedynamic op 519 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller, 520 Handle bootstrap_method, 521 Symbol* name, 522 Symbol* type, 523 Handle *appendix_result, 524 Handle *method_type_result, 525 TRAPS); 526 527 // Utility for printing loader "name" as part of tracing constraints 528 static const char* loader_name(oop loader) { 529 return ((loader) == NULL ? "<bootloader>" : 530 InstanceKlass::cast((loader)->klass())->name()->as_C_string() ); 531 } 532 static const char* loader_name(ClassLoaderData* loader_data) { 533 return (loader_data->class_loader() == NULL ? "<bootloader>" : 534 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() ); 535 } 536 537 // Record the error when the first attempt to resolve a reference from a constant 538 // pool entry to a class fails. 539 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error); 540 static void delete_resolution_error(ConstantPool* pool); 541 static Symbol* find_resolution_error(constantPoolHandle pool, int which); 542 543 private: 544 545 enum Constants { 546 _loader_constraint_size = 107, // number of entries in constraint table 547 _resolution_error_size = 107, // number of entries in resolution error table 548 _invoke_method_size = 139, // number of entries in invoke method table 549 _nof_buckets = 1009, // number of buckets in hash table for placeholders 550 _old_default_sdsize = 1009, // backward compat for system dictionary size 551 _prime_array_size = 8, // array of primes for system dictionary size 552 _average_depth_goal = 3 // goal for lookup length 553 }; 554 555 556 // Static variables 557 558 // hashtable sizes for system dictionary to allow growth 559 // prime numbers for system dictionary size 560 static int _sdgeneration; 561 static const int _primelist[_prime_array_size]; 562 563 // Hashtable holding loaded classes. 564 static Dictionary* _dictionary; 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 // _number_of_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 public: 590 // for VM_CounterDecay iteration support 591 friend class CounterDecay; 592 static Klass* try_get_next_class(); 593 594 private: 595 static void validate_protection_domain(instanceKlassHandle klass, 596 Handle class_loader, 597 Handle protection_domain, TRAPS); 598 599 friend class VM_PopulateDumpSharedSpace; 600 friend class TraversePlaceholdersClosure; 601 static Dictionary* dictionary() { return _dictionary; } 602 static Dictionary* shared_dictionary() { return _shared_dictionary; } 603 static PlaceholderTable* placeholders() { return _placeholders; } 604 static LoaderConstraintTable* constraints() { return _loader_constraints; } 605 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 606 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 607 608 // Basic loading operations 609 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 610 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 611 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 612 // Wait on SystemDictionary_lock; unlocks lockObject before 613 // waiting; relocks lockObject with correct recursion count 614 // after waiting, but before reentering SystemDictionary_lock 615 // to preserve lock order semantics. 616 static void double_lock_wait(Handle lockObject, TRAPS); 617 static void define_instance_class(instanceKlassHandle k, TRAPS); 618 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name, 619 Handle class_loader, 620 instanceKlassHandle k, TRAPS); 621 static instanceKlassHandle load_shared_class(Symbol* class_name, 622 Handle class_loader, TRAPS); 623 static instanceKlassHandle load_shared_class(instanceKlassHandle ik, 624 Handle class_loader, TRAPS); 625 static void clean_up_shared_class(instanceKlassHandle ik, Handle class_loader, TRAPS); 626 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 627 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 628 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 629 static bool is_parallelCapable(Handle class_loader); 630 static bool is_parallelDefine(Handle class_loader); 631 632 public: 633 static bool is_ext_class_loader(Handle class_loader); 634 635 private: 636 static Klass* find_shared_class(Symbol* class_name); 637 638 // Setup link to hierarchy 639 static void add_to_hierarchy(instanceKlassHandle k, TRAPS); 640 641 // event based tracing 642 static void post_class_load_event(TracingTime start_time, instanceKlassHandle k, 643 Handle initiating_loader); 644 // We pass in the hashtable index so we can calculate it outside of 645 // the SystemDictionary_lock. 646 647 // Basic find on loaded classes 648 static Klass* find_class(int index, unsigned int hash, 649 Symbol* name, ClassLoaderData* loader_data); 650 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 651 652 // Basic find on classes in the midst of being loaded 653 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 654 655 // Updating entry in dictionary 656 // Add a completely loaded class 657 static void add_klass(int index, Symbol* class_name, 658 ClassLoaderData* loader_data, KlassHandle obj); 659 660 // Add a placeholder for a class being loaded 661 static void add_placeholder(int index, 662 Symbol* class_name, 663 ClassLoaderData* loader_data); 664 static void remove_placeholder(int index, 665 Symbol* class_name, 666 ClassLoaderData* loader_data); 667 668 // Performs cleanups after resolve_super_or_fail. This typically needs 669 // to be called on failure. 670 // Won't throw, but can block. 671 static void resolution_cleanups(Symbol* class_name, 672 ClassLoaderData* loader_data, 673 TRAPS); 674 675 // Initialization 676 static void initialize_preloaded_classes(TRAPS); 677 678 // Class loader constraints 679 static void check_constraints(int index, unsigned int hash, 680 instanceKlassHandle k, Handle loader, 681 bool defining, TRAPS); 682 static void update_dictionary(int d_index, unsigned int d_hash, 683 int p_index, unsigned int p_hash, 684 instanceKlassHandle k, Handle loader, 685 TRAPS); 686 687 // Variables holding commonly used klasses (preloaded) 688 static Klass* _well_known_klasses[]; 689 690 // Lazily loaded klasses 691 static Klass* volatile _abstract_ownable_synchronizer_klass; 692 693 // table of box klasses (int_klass, etc.) 694 static Klass* _box_klasses[T_VOID+1]; 695 696 static oop _java_system_loader; 697 698 static bool _has_loadClassInternal; 699 static bool _has_checkPackageAccess; 700 }; 701 702 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP