1 /* 2 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP 26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP 27 28 #include "classfile/classFileStream.hpp" 29 #include "classfile/classLoader.hpp" 30 #include "oops/objArrayOop.hpp" 31 #include "oops/symbol.hpp" 32 #include "runtime/java.hpp" 33 #include "runtime/reflectionUtils.hpp" 34 #include "utilities/hashtable.hpp" 35 #include "utilities/hashtable.inline.hpp" 36 37 38 // The system dictionary stores all loaded classes and maps: 39 // 40 // [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass* 41 // 42 // Classes are loaded lazily. The default VM class loader is 43 // represented as NULL. 44 45 // The underlying data structure is an open hash table with a fixed number 46 // of buckets. During loading the loader object is locked, (for the VM loader 47 // a private lock object is used). Class loading can thus be done concurrently, 48 // but only by different loaders. 49 // 50 // During loading a placeholder (name, loader) is temporarily placed in 51 // a side data structure, and is used to detect ClassCircularityErrors 52 // and to perform verification during GC. A GC can occur in the midst 53 // of class loading, as we call out to Java, have to take locks, etc. 54 // 55 // When class loading is finished, a new entry is added to the system 56 // dictionary and the place holder is removed. Note that the protection 57 // domain field of the system dictionary has not yet been filled in when 58 // the "real" system dictionary entry is created. 59 // 60 // Clients of this class who are interested in finding if a class has 61 // been completely loaded -- not classes in the process of being loaded -- 62 // can read the SystemDictionary unlocked. This is safe because 63 // - entries are only deleted at safepoints 64 // - readers cannot come to a safepoint while actively examining 65 // an entry (an entry cannot be deleted from under a reader) 66 // - entries must be fully formed before they are available to concurrent 67 // readers (we must ensure write ordering) 68 // 69 // Note that placeholders are deleted at any time, as they are removed 70 // when a class is completely loaded. Therefore, readers as well as writers 71 // of placeholders must hold the SystemDictionary_lock. 72 // 73 74 class Dictionary; 75 class PlaceholderTable; 76 class LoaderConstraintTable; 77 template <MEMFLAGS F> class HashtableBucket; 78 class ResolutionErrorTable; 79 class SymbolPropertyTable; 80 class Ticks; 81 82 // Certain classes are preloaded, such as java.lang.Object and java.lang.String. 83 // They are all "well-known", in the sense that no class loader is allowed 84 // to provide a different definition. 85 // 86 // These klasses must all have names defined in vmSymbols. 87 88 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 89 90 // Each well-known class has a short klass name (like object_klass), 91 // a vmSymbol name (like java_lang_Object), and a flag word 92 // that makes some minor distinctions, like whether the klass 93 // is preloaded, optional, release-specific, etc. 94 // The order of these definitions is significant; it is the order in which 95 // preloading is actually performed by initialize_preloaded_classes. 96 97 #define WK_KLASSES_DO(do_klass) \ 98 /* well-known classes */ \ 99 do_klass(Object_klass, java_lang_Object, Pre ) \ 100 do_klass(String_klass, java_lang_String, Pre ) \ 101 do_klass(Class_klass, java_lang_Class, Pre ) \ 102 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \ 103 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \ 104 do_klass(Serializable_klass, java_io_Serializable, Pre ) \ 105 do_klass(System_klass, java_lang_System, Pre ) \ 106 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \ 107 do_klass(Error_klass, java_lang_Error, Pre ) \ 108 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \ 109 do_klass(Exception_klass, java_lang_Exception, Pre ) \ 110 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \ 111 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \ 112 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \ 113 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \ 114 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \ 115 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \ 116 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \ 117 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \ 118 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \ 119 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \ 120 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \ 121 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \ 122 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \ 123 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \ 124 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \ 125 \ 126 /* Preload ref klasses and set reference types */ \ 127 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \ 128 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \ 129 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \ 130 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \ 131 do_klass(Cleaner_klass, sun_misc_Cleaner, Pre ) \ 132 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \ 133 \ 134 do_klass(Thread_klass, java_lang_Thread, Pre ) \ 135 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \ 136 do_klass(Properties_klass, java_util_Properties, Pre ) \ 137 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \ 138 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \ 139 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \ 140 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \ 141 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \ 142 \ 143 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 144 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 145 do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \ 146 do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Pre ) \ 147 do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Pre ) \ 148 do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \ 149 do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt ) \ 150 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt ) \ 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(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \ 155 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \ 156 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \ 157 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \ 158 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \ 159 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \ 160 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \ 161 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \ 162 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \ 163 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \ 164 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \ 165 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 166 \ 167 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \ 168 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \ 169 do_klass(misc_Unsafe_klass, sun_misc_Unsafe, Pre ) \ 170 \ 171 /* support for CDS */ \ 172 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \ 173 do_klass(File_klass, java_io_File, Pre ) \ 174 do_klass(URLClassLoader_klass, java_net_URLClassLoader, Pre ) \ 175 do_klass(URL_klass, java_net_URL, Pre ) \ 176 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \ 177 do_klass(sun_misc_Launcher_klass, sun_misc_Launcher, Pre ) \ 178 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \ 179 \ 180 /* It's NULL in non-1.4 JDKs. */ \ 181 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 182 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 183 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \ 184 \ 185 /* Preload boxing klasses */ \ 186 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \ 187 do_klass(Character_klass, java_lang_Character, Pre ) \ 188 do_klass(Float_klass, java_lang_Float, Pre ) \ 189 do_klass(Double_klass, java_lang_Double, Pre ) \ 190 do_klass(Byte_klass, java_lang_Byte, Pre ) \ 191 do_klass(Short_klass, java_lang_Short, Pre ) \ 192 do_klass(Integer_klass, java_lang_Integer, Pre ) \ 193 do_klass(Long_klass, java_lang_Long, Pre ) \ 194 /*end*/ 195 196 197 class SystemDictionary : AllStatic { 198 friend class VMStructs; 199 friend class SystemDictionaryHandles; 200 201 public: 202 enum WKID { 203 NO_WKID = 0, 204 205 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 206 WK_KLASSES_DO(WK_KLASS_ENUM) 207 #undef WK_KLASS_ENUM 208 209 WKID_LIMIT, 210 211 FIRST_WKID = NO_WKID + 1 212 }; 213 214 enum InitOption { 215 Pre, // preloaded; error if not present 216 217 // Order is significant. Options before this point require resolve_or_fail. 218 // Options after this point will use resolve_or_null instead. 219 220 Opt, // preload tried; NULL if not present 221 OPTION_LIMIT, 222 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 223 }; 224 225 226 // Returns a class with a given class name and class loader. Loads the 227 // class if needed. If not found a NoClassDefFoundError or a 228 // ClassNotFoundException is thrown, depending on the value on the 229 // throw_error flag. For most uses the throw_error argument should be set 230 // to true. 231 232 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 233 // Convenient call for null loader and protection domain. 234 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 235 protected: 236 // handle error translation for resolve_or_null results 237 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, KlassHandle klass_h, TRAPS); 238 239 public: 240 241 // Returns a class with a given class name and class loader. 242 // Loads the class if needed. If not found NULL is returned. 243 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 244 // Version with null loader and protection domain 245 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 246 247 // Resolve a superclass or superinterface. Called from ClassFileParser, 248 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 249 // "child_name" is the class whose super class or interface is being resolved. 250 static Klass* resolve_super_or_fail(Symbol* child_name, 251 Symbol* class_name, 252 Handle class_loader, 253 Handle protection_domain, 254 bool is_superclass, 255 TRAPS); 256 257 // Parse new stream. This won't update the system dictionary or 258 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 259 static Klass* parse_stream(Symbol* class_name, 260 Handle class_loader, 261 Handle protection_domain, 262 ClassFileStream* st, 263 TRAPS) { 264 KlassHandle nullHandle; 265 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD); 266 } 267 static Klass* parse_stream(Symbol* class_name, 268 Handle class_loader, 269 Handle protection_domain, 270 ClassFileStream* st, 271 KlassHandle host_klass, 272 GrowableArray<Handle>* cp_patches, 273 TRAPS); 274 275 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 276 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader, 277 Handle protection_domain, 278 ClassFileStream* st, bool verify, TRAPS); 279 280 // Lookup an already loaded class. If not found NULL is returned. 281 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 282 283 // Lookup an already loaded instance or array class. 284 // Do not make any queries to class loaders; consult only the cache. 285 // If not found NULL is returned. 286 static Klass* find_instance_or_array_klass(Symbol* class_name, 287 Handle class_loader, 288 Handle protection_domain, 289 TRAPS); 290 291 // Lookup an instance or array class that has already been loaded 292 // either into the given class loader, or else into another class 293 // loader that is constrained (via loader constraints) to produce 294 // a consistent class. Do not take protection domains into account. 295 // Do not make any queries to class loaders; consult only the cache. 296 // Return NULL if the class is not found. 297 // 298 // This function is a strict superset of find_instance_or_array_klass. 299 // This function (the unchecked version) makes a conservative prediction 300 // of the result of the checked version, assuming successful lookup. 301 // If both functions return non-null, they must return the same value. 302 // Also, the unchecked version may sometimes be non-null where the 303 // checked version is null. This can occur in several ways: 304 // 1. No query has yet been made to the class loader. 305 // 2. The class loader was queried, but chose not to delegate. 306 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 307 // 4. Loading was attempted, but there was a linkage error of some sort. 308 // In all of these cases, the loader constraints on this type are 309 // satisfied, and it is safe for classes in the given class loader 310 // to manipulate strongly-typed values of the found class, subject 311 // to local linkage and access checks. 312 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 313 Handle class_loader, 314 TRAPS); 315 316 // Iterate over all klasses in dictionary 317 // Just the classes from defining class loaders 318 static void classes_do(void f(Klass*)); 319 // Added for initialize_itable_for_klass to handle exceptions 320 static void classes_do(void f(Klass*, TRAPS), TRAPS); 321 // All classes, and their class loaders 322 static void classes_do(void f(Klass*, ClassLoaderData*)); 323 324 static void placeholders_do(void f(Symbol*)); 325 326 // Iterate over all methods in all klasses in dictionary 327 static void methods_do(void f(Method*)); 328 329 // Garbage collection support 330 331 // This method applies "blk->do_oop" to all the pointers to "system" 332 // classes and loaders. 333 static void always_strong_oops_do(OopClosure* blk); 334 static void always_strong_classes_do(KlassClosure* closure); 335 336 // Unload (that is, break root links to) all unmarked classes and 337 // loaders. Returns "true" iff something was unloaded. 338 static bool do_unloading(BoolObjectClosure* is_alive, 339 bool clean_previous_versions = true); 340 341 // Used by DumpSharedSpaces only to remove classes that failed verification 342 static void remove_classes_in_error_state(); 343 344 static int calculate_systemdictionary_size(int loadedclasses); 345 346 // Applies "f->do_oop" to all root oops in the system dictionary. 347 static void oops_do(OopClosure* f); 348 static void roots_oops_do(OopClosure* strong, OopClosure* weak); 349 350 // System loader lock 351 static oop system_loader_lock() { return _system_loader_lock_obj; } 352 353 protected: 354 // Extended Redefine classes support (tbi) 355 static void preloaded_classes_do(KlassClosure* f); 356 static void lazily_loaded_classes_do(KlassClosure* f); 357 public: 358 // Sharing support. 359 static void reorder_dictionary(); 360 static void copy_buckets(char** top, char* end); 361 static void copy_table(char** top, char* end); 362 static void reverse(); 363 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 364 int number_of_entries); 365 // Printing 366 static void print(bool details = true); 367 static void print_shared(bool details = true); 368 static void print_class_statistics() PRODUCT_RETURN; 369 static void print_method_statistics() PRODUCT_RETURN; 370 371 // Number of contained klasses 372 // This is both fully loaded classes and classes in the process 373 // of being loaded 374 static int number_of_classes(); 375 376 // Monotonically increasing counter which grows as classes are 377 // loaded or modifications such as hot-swapping or setting/removing 378 // of breakpoints are performed 379 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 380 // Needed by evolution and breakpoint code 381 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 382 383 // Verification 384 static void verify(); 385 386 #ifdef ASSERT 387 static bool is_internal_format(Symbol* class_name); 388 #endif 389 390 // Initialization 391 static void initialize(TRAPS); 392 393 // Fast access to commonly used classes (preloaded) 394 static Klass* check_klass(Klass* k) { 395 assert(k != NULL, "preloaded klass not initialized"); 396 return k; 397 } 398 399 static Klass* check_klass_Pre( Klass* k) { return check_klass(k); } 400 static Klass* check_klass_Opt( Klass* k) { return k; } 401 402 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 403 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 404 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 405 int limit = (int)end_id + 1; 406 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 407 } 408 409 public: 410 #define WK_KLASS_DECLARE(name, symbol, option) \ 411 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 412 static Klass** name##_addr() { \ 413 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 414 } 415 WK_KLASSES_DO(WK_KLASS_DECLARE); 416 #undef WK_KLASS_DECLARE 417 418 static Klass* well_known_klass(WKID id) { 419 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 420 return _well_known_klasses[id]; 421 } 422 423 static Klass** well_known_klass_addr(WKID id) { 424 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 425 return &_well_known_klasses[id]; 426 } 427 428 // Local definition for direct access to the private array: 429 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 430 431 static Klass* box_klass(BasicType t) { 432 assert((uint)t < T_VOID+1, "range check"); 433 return check_klass(_box_klasses[t]); 434 } 435 static BasicType box_klass_type(Klass* k); // inverse of box_klass 436 437 // methods returning lazily loaded klasses 438 // The corresponding method to load the class must be called before calling them. 439 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 440 441 static void load_abstract_ownable_synchronizer_klass(TRAPS); 442 443 protected: 444 // Tells whether ClassLoader.loadClassInternal is present 445 static bool has_loadClassInternal() { return _has_loadClassInternal; } 446 447 // Returns the class loader data to be used when looking up/updating the 448 // system dictionary. 449 static ClassLoaderData *class_loader_data(Handle class_loader) { 450 return ClassLoaderData::class_loader_data(class_loader()); 451 } 452 453 public: 454 // Tells whether ClassLoader.checkPackageAccess is present 455 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 456 457 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 458 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 459 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 460 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 461 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 462 463 // Returns default system loader 464 static oop java_system_loader(); 465 466 // Compute the default system loader 467 static void compute_java_system_loader(TRAPS); 468 469 // Register a new class loader 470 static ClassLoaderData* register_loader(Handle class_loader, TRAPS); 471 protected: 472 // Mirrors for primitive classes (created eagerly) 473 static oop check_mirror(oop m) { 474 assert(m != NULL, "mirror not initialized"); 475 return m; 476 } 477 478 public: 479 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 480 481 // Check class loader constraints 482 static bool add_loader_constraint(Symbol* name, Handle loader1, 483 Handle loader2, TRAPS); 484 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 485 Handle loader2, bool is_method, TRAPS); 486 487 // JSR 292 488 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 489 // (asks Java to compute it if necessary, except in a compiler thread) 490 static methodHandle find_method_handle_invoker(Symbol* name, 491 Symbol* signature, 492 KlassHandle accessing_klass, 493 Handle *appendix_result, 494 Handle *method_type_result, 495 TRAPS); 496 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 497 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 498 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 499 Symbol* signature, 500 TRAPS); 501 // find a java.lang.invoke.MethodType object for a given signature 502 // (asks Java to compute it if necessary, except in a compiler thread) 503 static Handle find_method_handle_type(Symbol* signature, 504 KlassHandle accessing_klass, 505 TRAPS); 506 507 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 508 static Handle link_method_handle_constant(KlassHandle caller, 509 int ref_kind, //e.g., JVM_REF_invokeVirtual 510 KlassHandle callee, 511 Symbol* name, 512 Symbol* signature, 513 TRAPS); 514 515 // ask Java to create a dynamic call site, while linking an invokedynamic op 516 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller, 517 Handle bootstrap_method, 518 Symbol* name, 519 Symbol* type, 520 Handle *appendix_result, 521 Handle *method_type_result, 522 TRAPS); 523 524 // Utility for printing loader "name" as part of tracing constraints 525 static const char* loader_name(oop loader) { 526 return ((loader) == NULL ? "<bootloader>" : 527 InstanceKlass::cast((loader)->klass())->name()->as_C_string() ); 528 } 529 static const char* loader_name(ClassLoaderData* loader_data) { 530 return (loader_data->class_loader() == NULL ? "<bootloader>" : 531 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() ); 532 } 533 534 // Record the error when the first attempt to resolve a reference from a constant 535 // pool entry to a class fails. 536 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error, 537 Symbol* message); 538 static void delete_resolution_error(ConstantPool* pool); 539 static Symbol* find_resolution_error(constantPoolHandle pool, int which, 540 Symbol** message); 541 542 protected: 543 544 enum Constants { 545 _loader_constraint_size = 107, // number of entries in constraint table 546 _resolution_error_size = 107, // number of entries in resolution error table 547 _invoke_method_size = 139, // number of entries in invoke method table 548 _nof_buckets = 1009, // number of buckets in hash table for placeholders 549 _old_default_sdsize = 1009, // backward compat for system dictionary size 550 _prime_array_size = 8, // array of primes for system dictionary size 551 _average_depth_goal = 3 // goal for lookup length 552 }; 553 554 555 // Static variables 556 557 // hashtable sizes for system dictionary to allow growth 558 // prime numbers for system dictionary size 559 static int _sdgeneration; 560 static const int _primelist[_prime_array_size]; 561 562 // Hashtable holding loaded classes. 563 static Dictionary* _dictionary; 564 565 // Hashtable holding placeholders for classes being loaded. 566 static PlaceholderTable* _placeholders; 567 568 // Hashtable holding classes from the shared archive. 569 static Dictionary* _shared_dictionary; 570 571 // Monotonically increasing counter which grows with 572 // _number_of_classes as well as hot-swapping and breakpoint setting 573 // and removal. 574 static int _number_of_modifications; 575 576 // Lock object for system class loader 577 static oop _system_loader_lock_obj; 578 579 // Constraints on class loaders 580 static LoaderConstraintTable* _loader_constraints; 581 582 // Resolution errors 583 static ResolutionErrorTable* _resolution_errors; 584 585 // Invoke methods (JSR 292) 586 static SymbolPropertyTable* _invoke_method_table; 587 588 public: 589 // for VM_CounterDecay iteration support 590 friend class CounterDecay; 591 static Klass* try_get_next_class(); 592 593 protected: 594 static void validate_protection_domain(instanceKlassHandle klass, 595 Handle class_loader, 596 Handle protection_domain, TRAPS); 597 598 friend class VM_PopulateDumpSharedSpace; 599 friend class TraversePlaceholdersClosure; 600 static Dictionary* dictionary() { return _dictionary; } 601 static Dictionary* shared_dictionary() { return _shared_dictionary; } 602 static PlaceholderTable* placeholders() { return _placeholders; } 603 static LoaderConstraintTable* constraints() { return _loader_constraints; } 604 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 605 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 606 607 // Basic loading operations 608 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 609 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 610 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 611 // Wait on SystemDictionary_lock; unlocks lockObject before 612 // waiting; relocks lockObject with correct recursion count 613 // after waiting, but before reentering SystemDictionary_lock 614 // to preserve lock order semantics. 615 static void double_lock_wait(Handle lockObject, TRAPS); 616 static void define_instance_class(instanceKlassHandle k, TRAPS); 617 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name, 618 Handle class_loader, 619 instanceKlassHandle k, TRAPS); 620 static instanceKlassHandle load_shared_class(instanceKlassHandle ik, 621 Handle class_loader, 622 Handle protection_domain, 623 TRAPS); 624 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 625 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 626 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 627 static bool is_parallelCapable(Handle class_loader); 628 static bool is_parallelDefine(Handle class_loader); 629 630 public: 631 static instanceKlassHandle load_shared_class(Symbol* class_name, 632 Handle class_loader, 633 TRAPS); 634 static bool is_ext_class_loader(Handle class_loader); 635 636 protected: 637 static Klass* find_shared_class(Symbol* class_name); 638 639 // Setup link to hierarchy 640 static void add_to_hierarchy(instanceKlassHandle k, TRAPS); 641 642 // event based tracing 643 static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k, 644 Handle initiating_loader); 645 // We pass in the hashtable index so we can calculate it outside of 646 // the SystemDictionary_lock. 647 648 // Basic find on loaded classes 649 static Klass* find_class(int index, unsigned int hash, 650 Symbol* name, ClassLoaderData* loader_data); 651 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 652 653 // Basic find on classes in the midst of being loaded 654 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 655 656 // Updating entry in dictionary 657 // Add a completely loaded class 658 static void add_klass(int index, Symbol* class_name, 659 ClassLoaderData* loader_data, KlassHandle obj); 660 661 // Add a placeholder for a class being loaded 662 static void add_placeholder(int index, 663 Symbol* class_name, 664 ClassLoaderData* loader_data); 665 static void remove_placeholder(int index, 666 Symbol* class_name, 667 ClassLoaderData* loader_data); 668 669 // Performs cleanups after resolve_super_or_fail. This typically needs 670 // to be called on failure. 671 // Won't throw, but can block. 672 static void resolution_cleanups(Symbol* class_name, 673 ClassLoaderData* loader_data, 674 TRAPS); 675 676 // Initialization 677 static void initialize_preloaded_classes(TRAPS); 678 679 // Class loader constraints 680 static void check_constraints(int index, unsigned int hash, 681 instanceKlassHandle k, Handle loader, 682 bool defining, TRAPS); 683 static void update_dictionary(int d_index, unsigned int d_hash, 684 int p_index, unsigned int p_hash, 685 instanceKlassHandle k, Handle loader, 686 TRAPS); 687 688 // Variables holding commonly used klasses (preloaded) 689 static Klass* _well_known_klasses[]; 690 691 // Lazily loaded klasses 692 static Klass* volatile _abstract_ownable_synchronizer_klass; 693 694 // table of box klasses (int_klass, etc.) 695 static Klass* _box_klasses[T_VOID+1]; 696 697 static oop _java_system_loader; 698 699 static bool _has_loadClassInternal; 700 static bool _has_checkPackageAccess; 701 }; 702 703 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP