systemDictionary.hpp revision 3602:da91efe96a93
1/* 2 * Copyright (c) 1997, 2012, 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// The system dictionary stores all loaded classes and maps: 38// 39// [class name,class loader] -> class i.e. [Symbol*,oop] -> Klass* 40// 41// Classes are loaded lazily. The default VM class loader is 42// represented as NULL. 43 44// The underlying data structure is an open hash table with a fixed number 45// of buckets. During loading the loader object is locked, (for the VM loader 46// a private lock object is used). Class loading can thus be done concurrently, 47// but only by different loaders. 48// 49// During loading a placeholder (name, loader) is temporarily placed in 50// a side data structure, and is used to detect ClassCircularityErrors 51// and to perform verification during GC. A GC can occur in the midst 52// of class loading, as we call out to Java, have to take locks, etc. 53// 54// When class loading is finished, a new entry is added to the system 55// dictionary and the place holder is removed. Note that the protection 56// domain field of the system dictionary has not yet been filled in when 57// the "real" system dictionary entry is created. 58// 59// Clients of this class who are interested in finding if a class has 60// been completely loaded -- not classes in the process of being loaded -- 61// can read the SystemDictionary unlocked. This is safe because 62// - entries are only deleted at safepoints 63// - readers cannot come to a safepoint while actively examining 64// an entry (an entry cannot be deleted from under a reader) 65// - entries must be fully formed before they are available to concurrent 66// readers (we must ensure write ordering) 67// 68// Note that placeholders are deleted at any time, as they are removed 69// when a class is completely loaded. Therefore, readers as well as writers 70// of placeholders must hold the SystemDictionary_lock. 71// 72 73class Dictionary; 74class PlaceholderTable; 75class LoaderConstraintTable; 76template <MEMFLAGS F> class HashtableBucket; 77class ResolutionErrorTable; 78class SymbolPropertyTable; 79 80// Certain classes are preloaded, such as java.lang.Object and java.lang.String. 81// They are all "well-known", in the sense that no class loader is allowed 82// to provide a different definition. 83// 84// These klasses must all have names defined in vmSymbols. 85 86#define WK_KLASS_ENUM_NAME(kname) kname##_knum 87 88// Each well-known class has a short klass name (like object_klass), 89// a vmSymbol name (like java_lang_Object), and a flag word 90// that makes some minor distinctions, like whether the klass 91// is preloaded, optional, release-specific, etc. 92// The order of these definitions is significant; it is the order in which 93// preloading is actually performed by initialize_preloaded_classes. 94 95#define WK_KLASSES_DO(template) \ 96 /* well-known classes */ \ 97 template(Object_klass, java_lang_Object, Pre) \ 98 template(String_klass, java_lang_String, Pre) \ 99 template(Class_klass, java_lang_Class, Pre) \ 100 template(Cloneable_klass, java_lang_Cloneable, Pre) \ 101 template(ClassLoader_klass, java_lang_ClassLoader, Pre) \ 102 template(Serializable_klass, java_io_Serializable, Pre) \ 103 template(System_klass, java_lang_System, Pre) \ 104 template(Throwable_klass, java_lang_Throwable, Pre) \ 105 template(Error_klass, java_lang_Error, Pre) \ 106 template(ThreadDeath_klass, java_lang_ThreadDeath, Pre) \ 107 template(Exception_klass, java_lang_Exception, Pre) \ 108 template(RuntimeException_klass, java_lang_RuntimeException, Pre) \ 109 template(ProtectionDomain_klass, java_security_ProtectionDomain, Pre) \ 110 template(AccessControlContext_klass, java_security_AccessControlContext, Pre) \ 111 template(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre) \ 112 template(NoClassDefFoundError_klass, java_lang_NoClassDefFoundError, Pre) \ 113 template(LinkageError_klass, java_lang_LinkageError, Pre) \ 114 template(ClassCastException_klass, java_lang_ClassCastException, Pre) \ 115 template(ArrayStoreException_klass, java_lang_ArrayStoreException, Pre) \ 116 template(VirtualMachineError_klass, java_lang_VirtualMachineError, Pre) \ 117 template(OutOfMemoryError_klass, java_lang_OutOfMemoryError, Pre) \ 118 template(StackOverflowError_klass, java_lang_StackOverflowError, Pre) \ 119 template(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre) \ 120 template(Reference_klass, java_lang_ref_Reference, Pre) \ 121 \ 122 /* Preload ref klasses and set reference types */ \ 123 template(SoftReference_klass, java_lang_ref_SoftReference, Pre) \ 124 template(WeakReference_klass, java_lang_ref_WeakReference, Pre) \ 125 template(FinalReference_klass, java_lang_ref_FinalReference, Pre) \ 126 template(PhantomReference_klass, java_lang_ref_PhantomReference, Pre) \ 127 template(Finalizer_klass, java_lang_ref_Finalizer, Pre) \ 128 \ 129 template(Thread_klass, java_lang_Thread, Pre) \ 130 template(ThreadGroup_klass, java_lang_ThreadGroup, Pre) \ 131 template(Properties_klass, java_util_Properties, Pre) \ 132 template(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre) \ 133 template(reflect_Field_klass, java_lang_reflect_Field, Pre) \ 134 template(reflect_Method_klass, java_lang_reflect_Method, Pre) \ 135 template(reflect_Constructor_klass, java_lang_reflect_Constructor, Pre) \ 136 \ 137 /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */ \ 138 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \ 139 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 140 template(reflect_MagicAccessorImpl_klass, sun_reflect_MagicAccessorImpl, Opt) \ 141 template(reflect_MethodAccessorImpl_klass, sun_reflect_MethodAccessorImpl, Opt_Only_JDK14NewRef) \ 142 template(reflect_ConstructorAccessorImpl_klass, sun_reflect_ConstructorAccessorImpl, Opt_Only_JDK14NewRef) \ 143 template(reflect_DelegatingClassLoader_klass, sun_reflect_DelegatingClassLoader, Opt) \ 144 template(reflect_ConstantPool_klass, sun_reflect_ConstantPool, Opt_Only_JDK15) \ 145 template(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15) \ 146 \ 147 /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \ 148 template(MethodHandle_klass, java_lang_invoke_MethodHandle, Pre_JSR292) \ 149 template(MemberName_klass, java_lang_invoke_MemberName, Pre_JSR292) \ 150 template(MethodHandleNatives_klass, java_lang_invoke_MethodHandleNatives, Pre_JSR292) \ 151 template(LambdaForm_klass, java_lang_invoke_LambdaForm, Opt) \ 152 template(MethodType_klass, java_lang_invoke_MethodType, Pre_JSR292) \ 153 template(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre_JSR292) \ 154 template(CallSite_klass, java_lang_invoke_CallSite, Pre_JSR292) \ 155 template(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre_JSR292) \ 156 template(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre_JSR292) \ 157 template(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre_JSR292) \ 158 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 159 \ 160 template(StringBuffer_klass, java_lang_StringBuffer, Pre) \ 161 template(StringBuilder_klass, java_lang_StringBuilder, Pre) \ 162 \ 163 /* It's NULL in non-1.4 JDKs. */ \ 164 template(StackTraceElement_klass, java_lang_StackTraceElement, Opt) \ 165 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \ 166 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 167 template(nio_Buffer_klass, java_nio_Buffer, Opt) \ 168 \ 169 template(DownloadManager_klass, sun_jkernel_DownloadManager, Opt_Kernel) \ 170 \ 171 template(PostVMInitHook_klass, sun_misc_PostVMInitHook, Opt) \ 172 \ 173 /* Preload boxing klasses */ \ 174 template(Boolean_klass, java_lang_Boolean, Pre) \ 175 template(Character_klass, java_lang_Character, Pre) \ 176 template(Float_klass, java_lang_Float, Pre) \ 177 template(Double_klass, java_lang_Double, Pre) \ 178 template(Byte_klass, java_lang_Byte, Pre) \ 179 template(Short_klass, java_lang_Short, Pre) \ 180 template(Integer_klass, java_lang_Integer, Pre) \ 181 template(Long_klass, java_lang_Long, Pre) \ 182 /*end*/ 183 184 185class SystemDictionary : AllStatic { 186 friend class VMStructs; 187 friend class SystemDictionaryHandles; 188 189 public: 190 enum WKID { 191 NO_WKID = 0, 192 193 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 194 WK_KLASSES_DO(WK_KLASS_ENUM) 195 #undef WK_KLASS_ENUM 196 197 WKID_LIMIT, 198 199 FIRST_WKID = NO_WKID + 1 200 }; 201 202 enum InitOption { 203 Pre, // preloaded; error if not present 204 Pre_JSR292, // preloaded if EnableInvokeDynamic 205 206 // Order is significant. Options before this point require resolve_or_fail. 207 // Options after this point will use resolve_or_null instead. 208 209 Opt, // preload tried; NULL if not present 210 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection 211 Opt_Only_JDK15, // preload tried; use only with JDK1.5+ 212 Opt_Kernel, // preload tried only #ifdef KERNEL 213 OPTION_LIMIT, 214 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 215 }; 216 217 218 // Returns a class with a given class name and class loader. Loads the 219 // class if needed. If not found a NoClassDefFoundError or a 220 // ClassNotFoundException is thrown, depending on the value on the 221 // throw_error flag. For most uses the throw_error argument should be set 222 // to true. 223 224 static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 225 // Convenient call for null loader and protection domain. 226 static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 227private: 228 // handle error translation for resolve_or_null results 229 static Klass* handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS); 230 231public: 232 233 // Returns a class with a given class name and class loader. 234 // Loads the class if needed. If not found NULL is returned. 235 static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 236 // Version with null loader and protection domain 237 static Klass* resolve_or_null(Symbol* class_name, TRAPS); 238 239 // Resolve a superclass or superinterface. Called from ClassFileParser, 240 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 241 // "child_name" is the class whose super class or interface is being resolved. 242 static Klass* resolve_super_or_fail(Symbol* child_name, 243 Symbol* class_name, 244 Handle class_loader, 245 Handle protection_domain, 246 bool is_superclass, 247 TRAPS); 248 249 // Parse new stream. This won't update the system dictionary or 250 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 251 static Klass* parse_stream(Symbol* class_name, 252 Handle class_loader, 253 Handle protection_domain, 254 ClassFileStream* st, 255 TRAPS) { 256 KlassHandle nullHandle; 257 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD); 258 } 259 static Klass* parse_stream(Symbol* class_name, 260 Handle class_loader, 261 Handle protection_domain, 262 ClassFileStream* st, 263 KlassHandle host_klass, 264 GrowableArray<Handle>* cp_patches, 265 TRAPS); 266 267 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 268 static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader, 269 Handle protection_domain, 270 ClassFileStream* st, bool verify, TRAPS); 271 272 // Lookup an already loaded class. If not found NULL is returned. 273 static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 274 275 // Lookup an already loaded instance or array class. 276 // Do not make any queries to class loaders; consult only the cache. 277 // If not found NULL is returned. 278 static Klass* find_instance_or_array_klass(Symbol* class_name, 279 Handle class_loader, 280 Handle protection_domain, 281 TRAPS); 282 283 // If the given name is known to vmSymbols, return the well-know klass: 284 static Klass* find_well_known_klass(Symbol* class_name); 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 // All classes, and their class loaders 319 // (added for helpers that use HandleMarks and ResourceMarks) 320 static void classes_do(void f(Klass*, ClassLoaderData*, TRAPS), TRAPS); 321 // All entries in the placeholder table and their class loaders 322 static void placeholders_do(void f(Symbol*)); 323 324 // Iterate over all methods in all klasses in dictionary 325 static void methods_do(void f(Method*)); 326 327 // Garbage collection support 328 329 // This method applies "blk->do_oop" to all the pointers to "system" 330 // classes and loaders. 331 static void always_strong_oops_do(OopClosure* blk); 332 static void always_strong_classes_do(KlassClosure* closure); 333 334 // Unload (that is, break root links to) all unmarked classes and 335 // loaders. Returns "true" iff something was unloaded. 336 static bool do_unloading(BoolObjectClosure* is_alive); 337 338 static int calculate_systemdictionary_size(int loadedclasses); 339 340 // Applies "f->do_oop" to all root oops in the system dictionary. 341 static void oops_do(OopClosure* f); 342 343 // System loader lock 344 static oop system_loader_lock() { return _system_loader_lock_obj; } 345 346private: 347 // Extended Redefine classes support (tbi) 348 static void preloaded_classes_do(KlassClosure* f); 349 static void lazily_loaded_classes_do(KlassClosure* f); 350public: 351 // Sharing support. 352 static void reorder_dictionary(); 353 static void copy_buckets(char** top, char* end); 354 static void copy_table(char** top, char* end); 355 static void reverse(); 356 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 357 int number_of_entries); 358 // Printing 359 static void print() PRODUCT_RETURN; 360 static void print_class_statistics() PRODUCT_RETURN; 361 static void print_method_statistics() PRODUCT_RETURN; 362 363 // Number of contained klasses 364 // This is both fully loaded classes and classes in the process 365 // of being loaded 366 static int number_of_classes(); 367 368 // Monotonically increasing counter which grows as classes are 369 // loaded or modifications such as hot-swapping or setting/removing 370 // of breakpoints are performed 371 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 372 // Needed by evolution and breakpoint code 373 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 374 375 // Verification 376 static void verify(); 377 378#ifdef ASSERT 379 static bool is_internal_format(Symbol* class_name); 380#endif 381 382 // Verify class is in dictionary 383 static void verify_obj_klass_present(Symbol* class_name, 384 ClassLoaderData* loader_data); 385 386 // Initialization 387 static void initialize(TRAPS); 388 389 // Fast access to commonly used classes (preloaded) 390 static Klass* check_klass(Klass* k) { 391 assert(k != NULL, "preloaded klass not initialized"); 392 return k; 393 } 394 395 static Klass* check_klass_Pre(Klass* k) { return check_klass(k); } 396 static Klass* check_klass_Pre_JSR292(Klass* k) { return EnableInvokeDynamic ? check_klass(k) : k; } 397 static Klass* check_klass_Opt(Klass* k) { return k; } 398 static Klass* check_klass_Opt_Kernel(Klass* k) { return k; } //== Opt 399 static Klass* check_klass_Opt_Only_JDK15(Klass* k) { 400 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only"); 401 return k; 402 } 403 static Klass* check_klass_Opt_Only_JDK14NewRef(Klass* k) { 404 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only"); 405 // despite the optional loading, if you use this it must be present: 406 return check_klass(k); 407 } 408 409 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 410 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 411 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 412 int limit = (int)end_id + 1; 413 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 414 } 415 416public: 417 #define WK_KLASS_DECLARE(name, symbol, option) \ 418 static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \ 419 static Klass** name##_addr() { \ 420 return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 421 } 422 WK_KLASSES_DO(WK_KLASS_DECLARE); 423 #undef WK_KLASS_DECLARE 424 425 static Klass* well_known_klass(WKID id) { 426 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 427 return _well_known_klasses[id]; 428 } 429 430 static Klass** well_known_klass_addr(WKID id) { 431 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 432 return &_well_known_klasses[id]; 433 } 434 435 // Local definition for direct access to the private array: 436 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 437 438 static Klass* box_klass(BasicType t) { 439 assert((uint)t < T_VOID+1, "range check"); 440 return check_klass(_box_klasses[t]); 441 } 442 static BasicType box_klass_type(Klass* k); // inverse of box_klass 443 444 // methods returning lazily loaded klasses 445 // The corresponding method to load the class must be called before calling them. 446 static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 447 448 static void load_abstract_ownable_synchronizer_klass(TRAPS); 449 450private: 451 // Tells whether ClassLoader.loadClassInternal is present 452 static bool has_loadClassInternal() { return _has_loadClassInternal; } 453 454 // Returns the class loader data to be used when looking up/updating the 455 // system dictionary. 456 static ClassLoaderData *class_loader_data(Handle class_loader) { 457 return ClassLoaderData::class_loader_data(class_loader()); 458 } 459 460public: 461 // Tells whether ClassLoader.checkPackageAccess is present 462 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 463 464 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 465 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 466 static bool Object_klass_loaded() { return WK_KLASS(Object_klass) != NULL; } 467 static bool ClassLoader_klass_loaded() { return WK_KLASS(ClassLoader_klass) != NULL; } 468 469 // Returns default system loader 470 static oop java_system_loader(); 471 472 // Compute the default system loader 473 static void compute_java_system_loader(TRAPS); 474 475 // Register a new class loader 476 static ClassLoaderData* register_loader(Handle class_loader); 477private: 478 // Mirrors for primitive classes (created eagerly) 479 static oop check_mirror(oop m) { 480 assert(m != NULL, "mirror not initialized"); 481 return m; 482 } 483 484public: 485 // Note: java_lang_Class::primitive_type is the inverse of java_mirror 486 487 // Check class loader constraints 488 static bool add_loader_constraint(Symbol* name, Handle loader1, 489 Handle loader2, TRAPS); 490 static char* check_signature_loaders(Symbol* signature, Handle loader1, 491 Handle loader2, bool is_method, TRAPS); 492 493 // JSR 292 494 // find a java.lang.invoke.MethodHandle.invoke* method for a given signature 495 // (asks Java to compute it if necessary, except in a compiler thread) 496 static methodHandle find_method_handle_invoker(Symbol* name, 497 Symbol* signature, 498 KlassHandle accessing_klass, 499 Handle *appendix_result, 500 TRAPS); 501 // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic) 502 // (does not ask Java, since this is a low-level intrinsic defined by the JVM) 503 static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid, 504 Symbol* signature, 505 TRAPS); 506 // find a java.lang.invoke.MethodType object for a given signature 507 // (asks Java to compute it if necessary, except in a compiler thread) 508 static Handle find_method_handle_type(Symbol* signature, 509 KlassHandle accessing_klass, 510 TRAPS); 511 512 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 513 static Handle link_method_handle_constant(KlassHandle caller, 514 int ref_kind, //e.g., JVM_REF_invokeVirtual 515 KlassHandle callee, 516 Symbol* name, 517 Symbol* signature, 518 TRAPS); 519 520 // ask Java to create a dynamic call site, while linking an invokedynamic op 521 static methodHandle find_dynamic_call_site_invoker(KlassHandle caller, 522 Handle bootstrap_method, 523 Symbol* name, 524 Symbol* type, 525 Handle *appendix_result, 526 TRAPS); 527 528 // Utility for printing loader "name" as part of tracing constraints 529 static const char* loader_name(oop loader) { 530 return ((loader) == NULL ? "<bootloader>" : 531 InstanceKlass::cast((loader)->klass())->name()->as_C_string() ); 532 } 533 static const char* loader_name(ClassLoaderData* loader_data) { 534 return (loader_data->is_the_null_class_loader_data() ? "<bootloader>" : 535 InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() ); 536 } 537 538 // Record the error when the first attempt to resolve a reference from a constant 539 // pool entry to a class fails. 540 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error); 541 static void delete_resolution_error(ConstantPool* pool); 542 static Symbol* find_resolution_error(constantPoolHandle pool, int which); 543 544 private: 545 546 enum Constants { 547 _loader_constraint_size = 107, // number of entries in constraint table 548 _resolution_error_size = 107, // number of entries in resolution error table 549 _invoke_method_size = 139, // number of entries in invoke method table 550 _nof_buckets = 1009, // number of buckets in hash table for placeholders 551 _old_default_sdsize = 1009, // backward compat for system dictionary size 552 _prime_array_size = 8, // array of primes for system dictionary size 553 _average_depth_goal = 3 // goal for lookup length 554 }; 555 556 557 // Static variables 558 559 // hashtable sizes for system dictionary to allow growth 560 // prime numbers for system dictionary size 561 static int _sdgeneration; 562 static const int _primelist[_prime_array_size]; 563 564 // Hashtable holding loaded classes. 565 static Dictionary* _dictionary; 566 567 // Hashtable holding placeholders for classes being loaded. 568 static PlaceholderTable* _placeholders; 569 570 // Hashtable holding classes from the shared archive. 571 static Dictionary* _shared_dictionary; 572 573 // Monotonically increasing counter which grows with 574 // _number_of_classes as well as hot-swapping and breakpoint setting 575 // and removal. 576 static int _number_of_modifications; 577 578 // Lock object for system class loader 579 static oop _system_loader_lock_obj; 580 581 // Constraints on class loaders 582 static LoaderConstraintTable* _loader_constraints; 583 584 // Resolution errors 585 static ResolutionErrorTable* _resolution_errors; 586 587 // Invoke methods (JSR 292) 588 static SymbolPropertyTable* _invoke_method_table; 589 590public: 591 // for VM_CounterDecay iteration support 592 friend class CounterDecay; 593 static Klass* try_get_next_class(); 594 595private: 596 static void validate_protection_domain(instanceKlassHandle klass, 597 Handle class_loader, 598 Handle protection_domain, TRAPS); 599 600 friend class VM_PopulateDumpSharedSpace; 601 friend class TraversePlaceholdersClosure; 602 static Dictionary* dictionary() { return _dictionary; } 603 static Dictionary* shared_dictionary() { return _shared_dictionary; } 604 static PlaceholderTable* placeholders() { return _placeholders; } 605 static LoaderConstraintTable* constraints() { return _loader_constraints; } 606 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 607 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 608 609 // Basic loading operations 610 static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 611 static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 612 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 613 // Wait on SystemDictionary_lock; unlocks lockObject before 614 // waiting; relocks lockObject with correct recursion count 615 // after waiting, but before reentering SystemDictionary_lock 616 // to preserve lock order semantics. 617 static void double_lock_wait(Handle lockObject, TRAPS); 618 static void define_instance_class(instanceKlassHandle k, TRAPS); 619 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name, 620 Handle class_loader, 621 instanceKlassHandle k, TRAPS); 622 static instanceKlassHandle load_shared_class(Symbol* class_name, 623 Handle class_loader, TRAPS); 624 static instanceKlassHandle load_shared_class(instanceKlassHandle ik, 625 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 static Klass* find_shared_class(Symbol* class_name); 633 634 // Setup link to hierarchy 635 static void add_to_hierarchy(instanceKlassHandle k, TRAPS); 636 637private: 638 // We pass in the hashtable index so we can calculate it outside of 639 // the SystemDictionary_lock. 640 641 // Basic find on loaded classes 642 static Klass* find_class(int index, unsigned int hash, 643 Symbol* name, ClassLoaderData* loader_data); 644 static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data); 645 646 // Basic find on classes in the midst of being loaded 647 static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data); 648 649 // Updating entry in dictionary 650 // Add a completely loaded class 651 static void add_klass(int index, Symbol* class_name, 652 ClassLoaderData* loader_data, KlassHandle obj); 653 654 // Add a placeholder for a class being loaded 655 static void add_placeholder(int index, 656 Symbol* class_name, 657 ClassLoaderData* loader_data); 658 static void remove_placeholder(int index, 659 Symbol* class_name, 660 ClassLoaderData* loader_data); 661 662 // Performs cleanups after resolve_super_or_fail. This typically needs 663 // to be called on failure. 664 // Won't throw, but can block. 665 static void resolution_cleanups(Symbol* class_name, 666 ClassLoaderData* loader_data, 667 TRAPS); 668 669 // Initialization 670 static void initialize_preloaded_classes(TRAPS); 671 672 // Class loader constraints 673 static void check_constraints(int index, unsigned int hash, 674 instanceKlassHandle k, Handle loader, 675 bool defining, TRAPS); 676 static void update_dictionary(int d_index, unsigned int d_hash, 677 int p_index, unsigned int p_hash, 678 instanceKlassHandle k, Handle loader, 679 TRAPS); 680 681 // Variables holding commonly used klasses (preloaded) 682 static Klass* _well_known_klasses[]; 683 684 // Lazily loaded klasses 685 static Klass* volatile _abstract_ownable_synchronizer_klass; 686 687 // table of box klasses (int_klass, etc.) 688 static Klass* _box_klasses[T_VOID+1]; 689 690 static oop _java_system_loader; 691 692 static bool _has_loadClassInternal; 693 static bool _has_checkPackageAccess; 694}; 695 696#endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP 697