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 "classfile/systemDictionary_ext.hpp" 31 #include "oops/objArrayOop.hpp" 32 #include "oops/symbol.hpp" 33 #include "runtime/java.hpp" 34 #include "runtime/reflectionUtils.hpp" 35 #include "utilities/hashtable.hpp" 36 #include "utilities/hashtable.inline.hpp" 37 #include "jvmci/systemDictionary_jvmci.hpp" 38 39 40 // The system dictionary stores all loaded classes and maps: 41 // 42 // [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass* 43 // 44 // Classes are loaded lazily. The default VM class loader is 45 // represented as NULL. 46 47 // The underlying data structure is an open hash table with a fixed number 48 // of buckets. During loading the loader object is locked, (for the VM loader 49 // a private lock object is used). Class loading can thus be done concurrently, 50 // but only by different loaders. 51 // 52 // During loading a placeholder (name, loader) is temporarily placed in 53 // a side data structure, and is used to detect ClassCircularityErrors 54 // and to perform verification during GC. A GC can occur in the midst 55 // of class loading, as we call out to Java, have to take locks, etc. 56 // 57 // When class loading is finished, a new entry is added to the system 58 // dictionary and the place holder is removed. Note that the protection 59 // domain field of the system dictionary has not yet been filled in when 60 // the "real" system dictionary entry is created. 61 // 62 // Clients of this class who are interested in finding if a class has 63 // been completely loaded -- not classes in the process of being loaded -- 64 // can read the SystemDictionary unlocked. This is safe because 65 // - entries are only deleted at safepoints 66 // - readers cannot come to a safepoint while actively examining 67 // an entry (an entry cannot be deleted from under a reader) 68 // - entries must be fully formed before they are available to concurrent 69 // readers (we must ensure write ordering) 70 // 71 // Note that placeholders are deleted at any time, as they are removed 72 // when a class is completely loaded. Therefore, readers as well as writers 73 // of placeholders must hold the SystemDictionary_lock. 74 // 75 76 class Dictionary; 77 class PlaceholderTable; 78 class LoaderConstraintTable; 79 template <MEMFLAGS F> class HashtableBucket; 80 class ResolutionErrorTable; 81 class SymbolPropertyTable; 82 class Ticks; 83 84 // Certain classes are preloaded, such as java.lang.Object and java.lang.String. 85 // They are all "well-known", in the sense that no class loader is allowed 86 // to provide a different definition. 87 // 88 // These klasses must all have names defined in vmSymbols. 89 90 #define WK_KLASS_ENUM_NAME(kname) kname##_knum 91 92 // Each well-known class has a short klass name (like object_klass), 93 // a vmSymbol name (like java_lang_Object), and a flag word 94 // that makes some minor distinctions, like whether the klass 95 // is preloaded, optional, release-specific, etc. 96 // The order of these definitions is significant; it is the order in which 97 // preloading is actually performed by initialize_preloaded_classes. 98 99 #define WK_KLASSES_DO(do_klass) \ 100 /* well-known classes */ \ 101 do_klass(Object_klass, java_lang_Object, Pre ) \ 102 do_klass(String_klass, java_lang_String, Pre ) \ 103 do_klass(Class_klass, java_lang_Class, Pre ) \ 104 do_klass(Cloneable_klass, java_lang_Cloneable, Pre ) \ 105 do_klass(ClassLoader_klass, java_lang_ClassLoader, Pre ) \ 106 do_klass(Serializable_klass, java_io_Serializable, Pre ) \ 107 do_klass(System_klass, java_lang_System, Pre ) \ 108 do_klass(Throwable_klass, java_lang_Throwable, Pre ) \ 109 do_klass(Error_klass, java_lang_Error, Pre ) \ 110 do_klass(ThreadDeath_klass, java_lang_ThreadDeath, Pre ) \ 111 do_klass(Exception_klass, java_lang_Exception, Pre ) \ 112 do_klass(RuntimeException_klass, java_lang_RuntimeException, Pre ) \ 113 do_klass(SecurityManager_klass, java_lang_SecurityManager, Pre ) \ 114 do_klass(ProtectionDomain_klass, java_security_ProtectionDomain, Pre ) \ 115 do_klass(AccessControlContext_klass, java_security_AccessControlContext, Pre ) \ 116 do_klass(SecureClassLoader_klass, java_security_SecureClassLoader, Pre ) \ 117 do_klass(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre ) \ 118 do_klass(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre ) \ 119 do_klass(LinkageError_klass, java_lang_LinkageError, Pre ) \ 120 do_klass(ClassCastException_klass, java_lang_ClassCastException, Pre ) \ 121 do_klass(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre ) \ 122 do_klass(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre ) \ 123 do_klass(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre ) \ 124 do_klass(StackOverflowError_klass, java_lang_StackOverflowError, Pre ) \ 125 do_klass(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre ) \ 126 do_klass(Reference_klass, java_lang_ref_Reference, Pre ) \ 127 \ 128 /* Preload ref klasses and set reference types */ \ 129 do_klass(SoftReference_klass, java_lang_ref_SoftReference, Pre ) \ 130 do_klass(WeakReference_klass, java_lang_ref_WeakReference, Pre ) \ 131 do_klass(FinalReference_klass, java_lang_ref_FinalReference, Pre ) \ 132 do_klass(PhantomReference_klass, java_lang_ref_PhantomReference, Pre ) \ 133 do_klass(Cleaner_klass, sun_misc_Cleaner, Pre ) \ 134 do_klass(Finalizer_klass, java_lang_ref_Finalizer, Pre ) \ 135 \ 136 do_klass(Thread_klass, java_lang_Thread, Pre ) \ 137 do_klass(ThreadGroup_klass, java_lang_ThreadGroup, Pre ) \ 138 do_klass(Properties_klass, java_util_Properties, Pre ) \ 139 do_klass(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre ) \ 140 do_klass(reflect_Field_klass, java_lang_reflect_Field, Pre ) \ 141 do_klass(reflect_Parameter_klass, java_lang_reflect_Parameter, Opt ) \ 142 do_klass(reflect_Method_klass, java_lang_reflect_Method, Pre ) \ 143 do_klass(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre ) \ 144 \ 145 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 146 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 147 do_klass(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt ) \ 148 do_klass(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Pre ) \ 149 do_klass(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Pre ) \ 150 do_klass(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt ) \ 151 do_klass(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt ) \ 152 do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt ) \ 153 do_klass(reflect_CallerSensitive_klass, sun_reflect_CallerSensitive, Opt ) \ 154 \ 155 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 156 do_klass(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Opt ) \ 157 do_klass(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre ) \ 158 do_klass(MemberName_klass, java_lang_invoke_MemberName, Pre ) \ 159 do_klass(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre ) \ 160 do_klass(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt ) \ 161 do_klass(MethodType_klass, java_lang_invoke_MethodType, Pre ) \ 162 do_klass(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre ) \ 163 do_klass(CallSite_klass, java_lang_invoke_CallSite, Pre ) \ 164 do_klass(Context_klass, java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre ) \ 165 do_klass(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre ) \ 166 do_klass(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre ) \ 167 do_klass(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre ) \ 168 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 169 \ 170 do_klass(StringBuffer_klass, java_lang_StringBuffer, Pre ) \ 171 do_klass(StringBuilder_klass, java_lang_StringBuilder, Pre ) \ 172 do_klass(internal_Unsafe_klass, jdk_internal_misc_Unsafe, Pre ) \ 173 \ 174 /* support for CDS */ \ 175 do_klass(ByteArrayInputStream_klass, java_io_ByteArrayInputStream, Pre ) \ 176 do_klass(File_klass, java_io_File, Pre ) \ 177 do_klass(URLClassLoader_klass, java_net_URLClassLoader, Pre ) \ 178 do_klass(URL_klass, java_net_URL, Pre ) \ 179 do_klass(Jar_Manifest_klass, java_util_jar_Manifest, Pre ) \ 180 do_klass(sun_misc_Launcher_klass, sun_misc_Launcher, Pre ) \ 181 do_klass(CodeSource_klass, java_security_CodeSource, Pre ) \ 182 \ 183 /* It's NULL in non-1.4 JDKs. */ \ 184 do_klass(StackTraceElement_klass, java_lang_StackTraceElement, Opt ) \ 185 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 186 do_klass(nio_Buffer_klass, java_nio_Buffer, Opt ) \ 187 \ 188 /* Preload boxing klasses */ \ 189 do_klass(Boolean_klass, java_lang_Boolean, Pre ) \ 190 do_klass(Character_klass, java_lang_Character, Pre ) \ 191 do_klass(Float_klass, java_lang_Float, Pre ) \ 192 do_klass(Double_klass, java_lang_Double, Pre ) \ 193 do_klass(Byte_klass, java_lang_Byte, Pre ) \ 194 do_klass(Short_klass, java_lang_Short, Pre ) \ 195 do_klass(Integer_klass, java_lang_Integer, Pre ) \ 196 do_klass(Long_klass, java_lang_Long, Pre ) \ 197 \ 198 /* Extensions */ \ 199 WK_KLASSES_DO_EXT(do_klass) \ 200 /* JVMCI classes. These are loaded on-demand. */ \ 201 JVMCI_WK_KLASSES_DO(do_klass) \ 202 \ 203 /*end*/ 204 205 206 class SystemDictionary : AllStatic { 207 friend class VMStructs; 208 friend class SystemDictionaryHandles; 209 friend class SharedClassUtil; 210 211 public: 212 enum WKID { 213 NO_WKID = 0, 214 215 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 216 WK_KLASSES_DO(WK_KLASS_ENUM) 217 #undef WK_KLASS_ENUM 218 219 WKID_LIMIT, 220 221 #if INCLUDE_JVMCI 222 FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(HotSpotCompiledCode_klass), 223 LAST_JVMCI_WKID = WK_KLASS_ENUM_NAME(Value_klass), 224 #endif 225 226 FIRST_WKID = NO_WKID + 1 227 }; 228 229 enum InitOption { 230 Pre, // preloaded; error if not present 231 232 // Order is significant. Options before this point require resolve_or_fail. 233 // Options after this point will use resolve_or_null instead. 234 235 Opt, // preload tried; NULL if not present 236 #if INCLUDE_JVMCI 237 Jvmci, // preload tried; error if not present, use only with JVMCI 238 #endif 239 OPTION_LIMIT, 240 CEIL_LG_OPTION_LIMIT = 2 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 241 }; 242 243 244 // Returns a class with a given class name and class loader. Loads the 245 // class if needed. If not found a NoClassDefFoundError or a 246 // ClassNotFoundException is thrown, depending on the value on the 247 // throw_error flag. For most uses the throw_error argument should be set 248 // to true. 249 250 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 251 // Convenient call for null loader and protection domain. 252 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 253 protected: 254 // handle error translation for resolve_or_null results 255 static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, KlassHandle klass_h, TRAPS); 256 257 public: 258 259 // Returns a class with a given class name and class loader. 260 // Loads the class if needed. If not found NULL is returned. 261 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 262 // Version with null loader and protection domain 263 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 264 265 // Resolve a superclass or superinterface. Called from ClassFileParser, 266 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 267 // "child_name" is the class whose super class or interface is being resolved. 268 static Klass* resolve_super_or_fail(Symbol* child_name, 269 Symbol* class_name, 270 Handle class_loader, 271 Handle protection_domain, 272 bool is_superclass, 273 TRAPS); 274 275 // Parse new stream. This won't update the system dictionary or 276 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 277 static Klass* parse_stream(Symbol* class_name, 278 Handle class_loader, 279 Handle protection_domain, 280 ClassFileStream* st, 281 TRAPS) { 282 KlassHandle nullHandle; 283 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD); 284 } 285 static Klass* parse_stream(Symbol* class_name, 286 Handle class_loader, 287 Handle protection_domain, 288 ClassFileStream* st, 289 KlassHandle host_klass, 290 GrowableArray<Handle>* cp_patches, 291 TRAPS); 292 293 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 294 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader, 295 Handle protection_domain, 296 ClassFileStream* st, bool verify, TRAPS); 297 298 // Lookup an already loaded class. If not found NULL is returned. 299 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 300 301 // Lookup an already loaded instance or array class. 302 // Do not make any queries to class loaders; consult only the cache. 303 // If not found NULL is returned. 304 static Klass* find_instance_or_array_klass(Symbol* class_name, 305 Handle class_loader, 306 Handle protection_domain, 307 TRAPS); 308 309 // Lookup an instance or array class that has already been loaded 310 // either into the given class loader, or else into another class 311 // loader that is constrained (via loader constraints) to produce 312 // a consistent class. Do not take protection domains into account. 313 // Do not make any queries to class loaders; consult only the cache. 314 // Return NULL if the class is not found. 315 // 316 // This function is a strict superset of find_instance_or_array_klass. 317 // This function (the unchecked version) makes a conservative prediction 318 // of the result of the checked version, assuming successful lookup. 319 // If both functions return non-null, they must return the same value. 320 // Also, the unchecked version may sometimes be non-null where the 321 // checked version is null. This can occur in several ways: 322 // 1. No query has yet been made to the class loader. 323 // 2. The class loader was queried, but chose not to delegate. 324 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 325 // 4. Loading was attempted, but there was a linkage error of some sort. 326 // In all of these cases, the loader constraints on this type are 327 // satisfied, and it is safe for classes in the given class loader 328 // to manipulate strongly-typed values of the found class, subject 329 // to local linkage and access checks. 330 static Klass* find_constrained_instance_or_array_klass(Symbol* class_name, 331 Handle class_loader, 332 TRAPS); 333 334 // Iterate over all klasses in dictionary 335 // Just the classes from defining class loaders 336 static void classes_do(void f(Klass*)); 337 // Added for initialize_itable_for_klass to handle exceptions 338 static void classes_do(void f(Klass*, TRAPS), TRAPS); 339 // All classes, and their class loaders 340 static void classes_do(void f(Klass*, ClassLoaderData*)); 341 342 static void placeholders_do(void f(Symbol*)); 343 344 // Iterate over all methods in all klasses in dictionary 345 static void methods_do(void f(Method*)); 346 347 // Garbage collection support 348 349 // This method applies "blk->do_oop" to all the pointers to "system" 350 // classes and loaders. 351 static void always_strong_oops_do(OopClosure* blk); 352 static void always_strong_classes_do(KlassClosure* closure); 353 354 // Unload (that is, break root links to) all unmarked classes and 355 // loaders. Returns "true" iff something was unloaded. 356 static bool do_unloading(BoolObjectClosure* is_alive, 357 bool clean_previous_versions = true); 358 359 // Used by DumpSharedSpaces only to remove classes that failed verification 360 static void remove_classes_in_error_state(); 361 362 static int calculate_systemdictionary_size(int loadedclasses); 363 364 // Applies "f->do_oop" to all root oops in the system dictionary. 365 static void oops_do(OopClosure* f); 366 static void roots_oops_do(OopClosure* strong, OopClosure* weak); 367 368 // System loader lock 369 static oop system_loader_lock() { return _system_loader_lock_obj; } 370 371 protected: 372 // Extended Redefine classes support (tbi) 373 static void preloaded_classes_do(KlassClosure* f); 374 static void lazily_loaded_classes_do(KlassClosure* f); 375 public: 376 // Sharing support. 377 static void reorder_dictionary(); 378 static void copy_buckets(char** top, char* end); 379 static void copy_table(char** top, char* end); 380 static void reverse(); 381 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 382 int number_of_entries); 383 // Printing 384 static void print(bool details = true); 385 static void print_shared(bool details = true); 386 387 // Number of contained klasses 388 // This is both fully loaded classes and classes in the process 389 // of being loaded 390 static int number_of_classes(); 391 392 // Monotonically increasing counter which grows as classes are 393 // loaded or modifications such as hot-swapping or setting/removing 394 // of breakpoints are performed 395 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 396 // Needed by evolution and breakpoint code 397 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 398 399 // Verification 400 static void verify(); 401 402 #ifdef ASSERT 403 static bool is_internal_format(Symbol* class_name); 404 #endif 405 406 // Initialization 407 static void initialize(TRAPS); 408 409 // Fast access to commonly used classes (preloaded) 410 static InstanceKlass* check_klass(InstanceKlass* k) { 411 assert(k != NULL, "preloaded klass not initialized"); 412 return k; 413 } 414 415 static InstanceKlass* check_klass_Pre(InstanceKlass* k) { return check_klass(k); } 416 static InstanceKlass* check_klass_Opt(InstanceKlass* k) { return k; } 417 418 JVMCI_ONLY(static InstanceKlass* check_klass_Jvmci(InstanceKlass* k) { return k; }) 419 420 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 421 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 422 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 423 int limit = (int)end_id + 1; 424 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 425 } 426 427 public: 428 #define WK_KLASS_DECLARE(name, symbol, option) \ 429 static InstanceKlass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 430 static InstanceKlass** name##_addr() { \ 431 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 432 } 433 WK_KLASSES_DO(WK_KLASS_DECLARE); 434 #undef WK_KLASS_DECLARE 435 436 static InstanceKlass* well_known_klass(WKID id) { 437 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 438 return _well_known_klasses[id]; 439 } 440 441 static InstanceKlass** well_known_klass_addr(WKID id) { 442 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 443 return &_well_known_klasses[id]; 444 } 445 446 // Local definition for direct access to the private array: 447 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 448 449 static InstanceKlass* box_klass(BasicType t) { 450 assert((uint)t < T_VOID+1, "range check"); 451 return check_klass(_box_klasses[t]); 452 } 453 static BasicType box_klass_type(Klass* k); // inverse of box_klass 454 455 // methods returning lazily loaded klasses 456 // The corresponding method to load the class must be called before calling them. 457 static InstanceKlass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 458 459 static void load_abstract_ownable_synchronizer_klass(TRAPS); 460 461 protected: 462 // Tells whether ClassLoader.loadClassInternal is present 463 static bool has_loadClassInternal() { return _has_loadClassInternal; } 464 465 // Returns the class loader data to be used when looking up/updating the 466 // system dictionary. 467 static ClassLoaderData *class_loader_data(Handle class_loader) { 468 return ClassLoaderData::class_loader_data(class_loader()); 469 } 470 471 public: 472 // Tells whether ClassLoader.checkPackageAccess is present 473 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 474 475 static bool Parameter_klass_loaded() { return WK_KLASS(reflect_Parameter_klass) != NULL; } 476 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 477 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 478 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 479 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 480 481 // Returns default system loader 482 static oop java_system_loader(); 483 484 // Compute the default system loader 485 static void compute_java_system_loader(TRAPS); 486 487 // Register a new class loader 488 static ClassLoaderData* register_loader(Handle class_loader, TRAPS); 489 protected: 490 // Mirrors for primitive classes (created eagerly) 491 static oop check_mirror(oop m) { 492 assert(m != NULL, "mirror not initialized"); 493 return m; 494 } 495 496 public: 497 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 498 499 // Check class loader constraints 500 static bool add_loader_constraint(Symbol* name, Handle loader1, 501 Handle loader2, TRAPS); 502 static Symbol* check_signature_loaders(Symbol* signature, Handle loader1, 503 Handle loader2, bool is_method, TRAPS); 504 505 // JSR 292 506 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 507 // (asks Java to compute it if necessary, except in a compiler thread) 508 static methodHandle find_method_handle_invoker(Symbol* name, 509 Symbol* signature, 510 KlassHandle accessing_klass, 511 Handle *appendix_result, 512 Handle *method_type_result, 513 TRAPS); 514 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 515 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 516 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 517 Symbol* signature, 518 TRAPS); 519 // find a java.lang.invoke.MethodType object for a given signature 520 // (asks Java to compute it if necessary, except in a compiler thread) 521 static Handle find_method_handle_type(Symbol* signature, 522 KlassHandle accessing_klass, 523 TRAPS); 524 525 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 526 static Handle link_method_handle_constant(KlassHandle caller, 527 int ref_kind, //e.g., JVM_REF_invokeVirtual 528 KlassHandle callee, 529 Symbol* name, 530 Symbol* signature, 531 TRAPS); 532 533 // ask Java to create a dynamic call site, while linking an invokedynamic op 534 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller, 535 Handle bootstrap_method, 536 Symbol* name, 537 Symbol* type, 538 Handle *appendix_result, 539 Handle *method_type_result, 540 TRAPS); 541 542 // Utility for printing loader "name" as part of tracing constraints 543 static const char* loader_name(oop loader) { 544 return ((loader) == NULL ? "<bootloader>" : 545 InstanceKlass::cast((loader)->klass())->name()->as_C_string() ); 546 } 547 static const char* loader_name(ClassLoaderData* loader_data) { 548 return (loader_data->class_loader() == NULL ? "<bootloader>" : 549 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() ); 550 } 551 552 // Record the error when the first attempt to resolve a reference from a constant 553 // pool entry to a class fails. 554 static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error, 555 Symbol* message); 556 static void delete_resolution_error(ConstantPool* pool); 557 static Symbol* find_resolution_error(const constantPoolHandle& pool, int which, 558 Symbol** message); 559 560 protected: 561 562 enum Constants { 563 _loader_constraint_size = 107, // number of entries in constraint table 564 _resolution_error_size = 107, // number of entries in resolution error table 565 _invoke_method_size = 139, // number of entries in invoke method table 566 _nof_buckets = 1009, // number of buckets in hash table for placeholders 567 _old_default_sdsize = 1009, // backward compat for system dictionary size 568 _prime_array_size = 8, // array of primes for system dictionary size 569 _average_depth_goal = 3 // goal for lookup length 570 }; 571 572 573 // Static variables 574 575 // hashtable sizes for system dictionary to allow growth 576 // prime numbers for system dictionary size 577 static int _sdgeneration; 578 static const int _primelist[_prime_array_size]; 579 580 // Hashtable holding loaded classes. 581 static Dictionary* _dictionary; 582 583 // Hashtable holding placeholders for classes being loaded. 584 static PlaceholderTable* _placeholders; 585 586 // Hashtable holding classes from the shared archive. 587 static Dictionary* _shared_dictionary; 588 589 // Monotonically increasing counter which grows with 590 // _number_of_classes as well as hot-swapping and breakpoint setting 591 // and removal. 592 static int _number_of_modifications; 593 594 // Lock object for system class loader 595 static oop _system_loader_lock_obj; 596 597 // Constraints on class loaders 598 static LoaderConstraintTable* _loader_constraints; 599 600 // Resolution errors 601 static ResolutionErrorTable* _resolution_errors; 602 603 // Invoke methods (JSR 292) 604 static SymbolPropertyTable* _invoke_method_table; 605 606 public: 607 // for VM_CounterDecay iteration support 608 friend class CounterDecay; 609 static Klass* try_get_next_class(); 610 611 protected: 612 static void validate_protection_domain(instanceKlassHandle klass, 613 Handle class_loader, 614 Handle protection_domain, TRAPS); 615 616 friend class VM_PopulateDumpSharedSpace; 617 friend class TraversePlaceholdersClosure; 618 static Dictionary* dictionary() { return _dictionary; } 619 static Dictionary* shared_dictionary() { return _shared_dictionary; } 620 static PlaceholderTable* placeholders() { return _placeholders; } 621 static LoaderConstraintTable* constraints() { return _loader_constraints; } 622 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 623 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 624 625 // Basic loading operations 626 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 627 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 628 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 629 // Wait on SystemDictionary_lock; unlocks lockObject before 630 // waiting; relocks lockObject with correct recursion count 631 // after waiting, but before reentering SystemDictionary_lock 632 // to preserve lock order semantics. 633 static void double_lock_wait(Handle lockObject, TRAPS); 634 static void define_instance_class(instanceKlassHandle k, TRAPS); 635 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name, 636 Handle class_loader, 637 instanceKlassHandle k, TRAPS); 638 static instanceKlassHandle load_shared_class(instanceKlassHandle ik, 639 Handle class_loader, 640 Handle protection_domain, 641 TRAPS); 642 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 643 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 644 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 645 static bool is_parallelCapable(Handle class_loader); 646 static bool is_parallelDefine(Handle class_loader); 647 648 public: 649 static instanceKlassHandle load_shared_class(Symbol* class_name, 650 Handle class_loader, 651 TRAPS); 652 static bool is_ext_class_loader(Handle class_loader); 653 654 protected: 655 static Klass* find_shared_class(Symbol* class_name); 656 657 // Setup link to hierarchy 658 static void add_to_hierarchy(instanceKlassHandle k, TRAPS); 659 660 // event based tracing 661 static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k, 662 Handle initiating_loader); 663 // We pass in the hashtable index so we can calculate it outside of 664 // the SystemDictionary_lock. 665 666 // Basic find on loaded classes 667 static Klass* find_class(int index, unsigned int hash, 668 Symbol* name, ClassLoaderData* loader_data); 669 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 670 671 // Basic find on classes in the midst of being loaded 672 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 673 674 // Add a placeholder for a class being loaded 675 static void add_placeholder(int index, 676 Symbol* class_name, 677 ClassLoaderData* loader_data); 678 static void remove_placeholder(int index, 679 Symbol* class_name, 680 ClassLoaderData* loader_data); 681 682 // Performs cleanups after resolve_super_or_fail. This typically needs 683 // to be called on failure. 684 // Won't throw, but can block. 685 static void resolution_cleanups(Symbol* class_name, 686 ClassLoaderData* loader_data, 687 TRAPS); 688 689 // Initialization 690 static void initialize_preloaded_classes(TRAPS); 691 692 // Class loader constraints 693 static void check_constraints(int index, unsigned int hash, 694 instanceKlassHandle k, Handle loader, 695 bool defining, TRAPS); 696 static void update_dictionary(int d_index, unsigned int d_hash, 697 int p_index, unsigned int p_hash, 698 instanceKlassHandle k, Handle loader, 699 TRAPS); 700 701 // Variables holding commonly used klasses (preloaded) 702 static InstanceKlass* _well_known_klasses[]; 703 704 // Lazily loaded klasses 705 static InstanceKlass* volatile _abstract_ownable_synchronizer_klass; 706 707 // table of box klasses (int_klass, etc.) 708 static InstanceKlass* _box_klasses[T_VOID+1]; 709 710 static oop _java_system_loader; 711 712 static bool _has_loadClassInternal; 713 static bool _has_checkPackageAccess; 714 }; 715 716 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP