systemDictionary.hpp revision 3465:d2a62e0f25eb
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] -> klassOop 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(AdapterMethodHandle_klass, java_lang_invoke_AdapterMethodHandle, Pre_JSR292) \ 152 template(BoundMethodHandle_klass, java_lang_invoke_BoundMethodHandle, Pre_JSR292) \ 153 template(DirectMethodHandle_klass, java_lang_invoke_DirectMethodHandle, Pre_JSR292) \ 154 template(MethodType_klass, java_lang_invoke_MethodType, Pre_JSR292) \ 155 template(MethodTypeForm_klass, java_lang_invoke_MethodTypeForm, Pre_JSR292) \ 156 template(BootstrapMethodError_klass, java_lang_BootstrapMethodError, Pre_JSR292) \ 157 template(WrongMethodTypeException_klass, java_lang_invoke_WrongMethodTypeException, Pre_JSR292) \ 158 template(CallSite_klass, java_lang_invoke_CallSite, Pre_JSR292) \ 159 template(CountingMethodHandle_klass, java_lang_invoke_CountingMethodHandle, Opt) \ 160 template(ConstantCallSite_klass, java_lang_invoke_ConstantCallSite, Pre_JSR292) \ 161 template(MutableCallSite_klass, java_lang_invoke_MutableCallSite, Pre_JSR292) \ 162 template(VolatileCallSite_klass, java_lang_invoke_VolatileCallSite, Pre_JSR292) \ 163 /* Note: MethodHandle must be first, and VolatileCallSite last in group */ \ 164 \ 165 template(StringBuffer_klass, java_lang_StringBuffer, Pre) \ 166 template(StringBuilder_klass, java_lang_StringBuilder, Pre) \ 167 \ 168 /* It's NULL in non-1.4 JDKs. */ \ 169 template(StackTraceElement_klass, java_lang_StackTraceElement, Opt) \ 170 /* Universe::is_gte_jdk14x_version() is not set up by this point. */ \ 171 /* It's okay if this turns out to be NULL in non-1.4 JDKs. */ \ 172 template(nio_Buffer_klass, java_nio_Buffer, Opt) \ 173 \ 174 template(DownloadManager_klass, sun_jkernel_DownloadManager, Opt_Kernel) \ 175 \ 176 template(PostVMInitHook_klass, sun_misc_PostVMInitHook, Opt) \ 177 \ 178 /* Preload boxing klasses */ \ 179 template(Boolean_klass, java_lang_Boolean, Pre) \ 180 template(Character_klass, java_lang_Character, Pre) \ 181 template(Float_klass, java_lang_Float, Pre) \ 182 template(Double_klass, java_lang_Double, Pre) \ 183 template(Byte_klass, java_lang_Byte, Pre) \ 184 template(Short_klass, java_lang_Short, Pre) \ 185 template(Integer_klass, java_lang_Integer, Pre) \ 186 template(Long_klass, java_lang_Long, Pre) \ 187 /*end*/ 188 189 190class SystemDictionary : AllStatic { 191 friend class VMStructs; 192 friend class CompactingPermGenGen; 193 friend class SystemDictionaryHandles; 194 NOT_PRODUCT(friend class instanceKlassKlass;) 195 196 public: 197 enum WKID { 198 NO_WKID = 0, 199 200 #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name), 201 WK_KLASSES_DO(WK_KLASS_ENUM) 202 #undef WK_KLASS_ENUM 203 204 WKID_LIMIT, 205 206 FIRST_WKID = NO_WKID + 1 207 }; 208 209 enum InitOption { 210 Pre, // preloaded; error if not present 211 Pre_JSR292, // preloaded if EnableInvokeDynamic 212 213 // Order is significant. Options before this point require resolve_or_fail. 214 // Options after this point will use resolve_or_null instead. 215 216 Opt, // preload tried; NULL if not present 217 Opt_Only_JDK14NewRef, // preload tried; use only with NewReflection 218 Opt_Only_JDK15, // preload tried; use only with JDK1.5+ 219 Opt_Kernel, // preload tried only #ifdef KERNEL 220 OPTION_LIMIT, 221 CEIL_LG_OPTION_LIMIT = 4 // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT) 222 }; 223 224 225 // Returns a class with a given class name and class loader. Loads the 226 // class if needed. If not found a NoClassDefFoundError or a 227 // ClassNotFoundException is thrown, depending on the value on the 228 // throw_error flag. For most uses the throw_error argument should be set 229 // to true. 230 231 static klassOop resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS); 232 // Convenient call for null loader and protection domain. 233 static klassOop resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS); 234private: 235 // handle error translation for resolve_or_null results 236 static klassOop handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS); 237 238public: 239 240 // Returns a class with a given class name and class loader. 241 // Loads the class if needed. If not found NULL is returned. 242 static klassOop resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 243 // Version with null loader and protection domain 244 static klassOop resolve_or_null(Symbol* class_name, TRAPS); 245 246 // Resolve a superclass or superinterface. Called from ClassFileParser, 247 // parse_interfaces, resolve_instance_class_or_null, load_shared_class 248 // "child_name" is the class whose super class or interface is being resolved. 249 static klassOop resolve_super_or_fail(Symbol* child_name, 250 Symbol* class_name, 251 Handle class_loader, 252 Handle protection_domain, 253 bool is_superclass, 254 TRAPS); 255 256 // Parse new stream. This won't update the system dictionary or 257 // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses. 258 static klassOop parse_stream(Symbol* class_name, 259 Handle class_loader, 260 Handle protection_domain, 261 ClassFileStream* st, 262 TRAPS) { 263 KlassHandle nullHandle; 264 return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD); 265 } 266 static klassOop parse_stream(Symbol* class_name, 267 Handle class_loader, 268 Handle protection_domain, 269 ClassFileStream* st, 270 KlassHandle host_klass, 271 GrowableArray<Handle>* cp_patches, 272 TRAPS); 273 274 // Resolve from stream (called by jni_DefineClass and JVM_DefineClass) 275 static klassOop resolve_from_stream(Symbol* class_name, Handle class_loader, 276 Handle protection_domain, 277 ClassFileStream* st, bool verify, TRAPS); 278 279 // Lookup an already loaded class. If not found NULL is returned. 280 static klassOop find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 281 282 // Lookup an already loaded instance or array class. 283 // Do not make any queries to class loaders; consult only the cache. 284 // If not found NULL is returned. 285 static klassOop find_instance_or_array_klass(Symbol* class_name, 286 Handle class_loader, 287 Handle protection_domain, 288 TRAPS); 289 290 // If the given name is known to vmSymbols, return the well-know klass: 291 static klassOop find_well_known_klass(Symbol* class_name); 292 293 // Lookup an instance or array class that has already been loaded 294 // either into the given class loader, or else into another class 295 // loader that is constrained (via loader constraints) to produce 296 // a consistent class. Do not take protection domains into account. 297 // Do not make any queries to class loaders; consult only the cache. 298 // Return NULL if the class is not found. 299 // 300 // This function is a strict superset of find_instance_or_array_klass. 301 // This function (the unchecked version) makes a conservative prediction 302 // of the result of the checked version, assuming successful lookup. 303 // If both functions return non-null, they must return the same value. 304 // Also, the unchecked version may sometimes be non-null where the 305 // checked version is null. This can occur in several ways: 306 // 1. No query has yet been made to the class loader. 307 // 2. The class loader was queried, but chose not to delegate. 308 // 3. ClassLoader.checkPackageAccess rejected a proposed protection domain. 309 // 4. Loading was attempted, but there was a linkage error of some sort. 310 // In all of these cases, the loader constraints on this type are 311 // satisfied, and it is safe for classes in the given class loader 312 // to manipulate strongly-typed values of the found class, subject 313 // to local linkage and access checks. 314 static klassOop find_constrained_instance_or_array_klass(Symbol* class_name, 315 Handle class_loader, 316 TRAPS); 317 318 // Iterate over all klasses in dictionary 319 // Just the classes from defining class loaders 320 static void classes_do(void f(klassOop)); 321 // Added for initialize_itable_for_klass to handle exceptions 322 static void classes_do(void f(klassOop, TRAPS), TRAPS); 323 // All classes, and their class loaders 324 static void classes_do(void f(klassOop, oop)); 325 // All classes, and their class loaders 326 // (added for helpers that use HandleMarks and ResourceMarks) 327 static void classes_do(void f(klassOop, oop, TRAPS), TRAPS); 328 // All entries in the placeholder table and their class loaders 329 static void placeholders_do(void f(Symbol*, oop)); 330 331 // Iterate over all methods in all klasses in dictionary 332 static void methods_do(void f(methodOop)); 333 334 // Garbage collection support 335 336 // This method applies "blk->do_oop" to all the pointers to "system" 337 // classes and loaders. 338 static void always_strong_oops_do(OopClosure* blk); 339 static void always_strong_classes_do(OopClosure* blk); 340 // This method applies "blk->do_oop" to all the placeholders. 341 static void placeholders_do(OopClosure* blk); 342 343 // Unload (that is, break root links to) all unmarked classes and 344 // loaders. Returns "true" iff something was unloaded. 345 static bool do_unloading(BoolObjectClosure* is_alive); 346 347 static int calculate_systemdictionary_size(int loadedclasses); 348 349 // Applies "f->do_oop" to all root oops in the system dictionary. 350 static void oops_do(OopClosure* f); 351 352 // System loader lock 353 static oop system_loader_lock() { return _system_loader_lock_obj; } 354 355private: 356 // Traverses preloaded oops: various system classes. These are 357 // guaranteed to be in the perm gen. 358 static void preloaded_oops_do(OopClosure* f); 359 static void lazily_loaded_oops_do(OopClosure* f); 360 361public: 362 // Sharing support. 363 static void reorder_dictionary(); 364 static void copy_buckets(char** top, char* end); 365 static void copy_table(char** top, char* end); 366 static void reverse(); 367 static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length, 368 int number_of_entries); 369 // Printing 370 static void print() PRODUCT_RETURN; 371 static void print_class_statistics() PRODUCT_RETURN; 372 static void print_method_statistics() PRODUCT_RETURN; 373 374 // Number of contained klasses 375 // This is both fully loaded classes and classes in the process 376 // of being loaded 377 static int number_of_classes(); 378 379 // Monotonically increasing counter which grows as classes are 380 // loaded or modifications such as hot-swapping or setting/removing 381 // of breakpoints are performed 382 static inline int number_of_modifications() { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; } 383 // Needed by evolution and breakpoint code 384 static inline void notice_modification() { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications; } 385 386 // Verification 387 static void verify(); 388 389#ifdef ASSERT 390 static bool is_internal_format(Symbol* class_name); 391#endif 392 393 // Verify class is in dictionary 394 static void verify_obj_klass_present(Handle obj, 395 Symbol* class_name, 396 Handle class_loader); 397 398 // Initialization 399 static void initialize(TRAPS); 400 401 // Fast access to commonly used classes (preloaded) 402 static klassOop check_klass(klassOop k) { 403 assert(k != NULL, "preloaded klass not initialized"); 404 return k; 405 } 406 407 static klassOop check_klass_Pre(klassOop k) { return check_klass(k); } 408 static klassOop check_klass_Pre_JSR292(klassOop k) { return EnableInvokeDynamic ? check_klass(k) : k; } 409 static klassOop check_klass_Opt(klassOop k) { return k; } 410 static klassOop check_klass_Opt_Kernel(klassOop k) { return k; } //== Opt 411 static klassOop check_klass_Opt_Only_JDK15(klassOop k) { 412 assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only"); 413 return k; 414 } 415 static klassOop check_klass_Opt_Only_JDK14NewRef(klassOop k) { 416 assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only"); 417 // despite the optional loading, if you use this it must be present: 418 return check_klass(k); 419 } 420 421 static bool initialize_wk_klass(WKID id, int init_opt, TRAPS); 422 static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS); 423 static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) { 424 int limit = (int)end_id + 1; 425 initialize_wk_klasses_until((WKID) limit, start_id, THREAD); 426 } 427 428public: 429 #define WK_KLASS_DECLARE(name, symbol, option) \ 430 static klassOop name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } 431 WK_KLASSES_DO(WK_KLASS_DECLARE); 432 #undef WK_KLASS_DECLARE 433 434 static klassOop well_known_klass(WKID id) { 435 assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob"); 436 return _well_known_klasses[id]; 437 } 438 439 // Local definition for direct access to the private array: 440 #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)] 441 442 static klassOop box_klass(BasicType t) { 443 assert((uint)t < T_VOID+1, "range check"); 444 return check_klass(_box_klasses[t]); 445 } 446 static BasicType box_klass_type(klassOop k); // inverse of box_klass 447 448 // methods returning lazily loaded klasses 449 // The corresponding method to load the class must be called before calling them. 450 static klassOop abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); } 451 452 static void load_abstract_ownable_synchronizer_klass(TRAPS); 453 454private: 455 // Tells whether ClassLoader.loadClassInternal is present 456 static bool has_loadClassInternal() { return _has_loadClassInternal; } 457 458public: 459 // Tells whether ClassLoader.checkPackageAccess is present 460 static bool has_checkPackageAccess() { return _has_checkPackageAccess; } 461 462 static bool Class_klass_loaded() { return WK_KLASS(Class_klass) != NULL; } 463 static bool Cloneable_klass_loaded() { return WK_KLASS(Cloneable_klass) != NULL; } 464 465 // Returns default system loader 466 static oop java_system_loader(); 467 468 // Compute the default system loader 469 static void compute_java_system_loader(TRAPS); 470 471private: 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 478public: 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 char* check_signature_loaders(Symbol* signature, Handle loader1, 485 Handle loader2, bool is_method, TRAPS); 486 487 // JSR 292 488 // find the java.lang.invoke.MethodHandles::invoke method for a given signature 489 static methodOop find_method_handle_invoke(Symbol* name, 490 Symbol* signature, 491 KlassHandle accessing_klass, 492 TRAPS); 493 // ask Java to compute a java.lang.invoke.MethodType object for a given signature 494 static Handle find_method_handle_type(Symbol* signature, 495 KlassHandle accessing_klass, 496 bool for_invokeGeneric, 497 bool& return_bcp_flag, 498 TRAPS); 499 // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry 500 static Handle link_method_handle_constant(KlassHandle caller, 501 int ref_kind, //e.g., JVM_REF_invokeVirtual 502 KlassHandle callee, 503 Symbol* name, 504 Symbol* signature, 505 TRAPS); 506 // ask Java to create a dynamic call site, while linking an invokedynamic op 507 static Handle make_dynamic_call_site(Handle bootstrap_method, 508 // Callee information: 509 Symbol* name, 510 methodHandle signature_invoker, 511 Handle info, 512 // Caller information: 513 methodHandle caller_method, 514 int caller_bci, 515 TRAPS); 516 517 // coordinate with Java about bootstrap methods 518 static Handle find_bootstrap_method(methodHandle caller_method, 519 int caller_bci, // N.B. must be an invokedynamic 520 int cache_index, // must be corresponding main_entry 521 Handle &argument_info_result, // static BSM arguments, if any 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 } 529 530 // Record the error when the first attempt to resolve a reference from a constant 531 // pool entry to a class fails. 532 static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error); 533 static Symbol* find_resolution_error(constantPoolHandle pool, int which); 534 535 private: 536 537 enum Constants { 538 _loader_constraint_size = 107, // number of entries in constraint table 539 _resolution_error_size = 107, // number of entries in resolution error table 540 _invoke_method_size = 139, // number of entries in invoke method table 541 _nof_buckets = 1009, // number of buckets in hash table for placeholders 542 _old_default_sdsize = 1009, // backward compat for system dictionary size 543 _prime_array_size = 8, // array of primes for system dictionary size 544 _average_depth_goal = 3 // goal for lookup length 545 }; 546 547 548 // Static variables 549 550 // hashtable sizes for system dictionary to allow growth 551 // prime numbers for system dictionary size 552 static int _sdgeneration; 553 static const int _primelist[_prime_array_size]; 554 555 // Hashtable holding loaded classes. 556 static Dictionary* _dictionary; 557 558 // Hashtable holding placeholders for classes being loaded. 559 static PlaceholderTable* _placeholders; 560 561 // Hashtable holding classes from the shared archive. 562 static Dictionary* _shared_dictionary; 563 564 // Monotonically increasing counter which grows with 565 // _number_of_classes as well as hot-swapping and breakpoint setting 566 // and removal. 567 static int _number_of_modifications; 568 569 // Lock object for system class loader 570 static oop _system_loader_lock_obj; 571 572 // Constraints on class loaders 573 static LoaderConstraintTable* _loader_constraints; 574 575 // Resolution errors 576 static ResolutionErrorTable* _resolution_errors; 577 578 // Invoke methods (JSR 292) 579 static SymbolPropertyTable* _invoke_method_table; 580 581public: 582 // for VM_CounterDecay iteration support 583 friend class CounterDecay; 584 static klassOop try_get_next_class(); 585 586private: 587 static void validate_protection_domain(instanceKlassHandle klass, 588 Handle class_loader, 589 Handle protection_domain, TRAPS); 590 591 friend class VM_PopulateDumpSharedSpace; 592 friend class TraversePlaceholdersClosure; 593 static Dictionary* dictionary() { return _dictionary; } 594 static Dictionary* shared_dictionary() { return _shared_dictionary; } 595 static PlaceholderTable* placeholders() { return _placeholders; } 596 static LoaderConstraintTable* constraints() { return _loader_constraints; } 597 static ResolutionErrorTable* resolution_errors() { return _resolution_errors; } 598 static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; } 599 600 // Basic loading operations 601 static klassOop resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 602 static klassOop resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS); 603 static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS); 604 // Wait on SystemDictionary_lock; unlocks lockObject before 605 // waiting; relocks lockObject with correct recursion count 606 // after waiting, but before reentering SystemDictionary_lock 607 // to preserve lock order semantics. 608 static void double_lock_wait(Handle lockObject, TRAPS); 609 static void define_instance_class(instanceKlassHandle k, TRAPS); 610 static instanceKlassHandle find_or_define_instance_class(Symbol* class_name, 611 Handle class_loader, 612 instanceKlassHandle k, TRAPS); 613 static instanceKlassHandle load_shared_class(Symbol* class_name, 614 Handle class_loader, TRAPS); 615 static instanceKlassHandle load_shared_class(instanceKlassHandle ik, 616 Handle class_loader, TRAPS); 617 static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS); 618 static Handle compute_loader_lock_object(Handle class_loader, TRAPS); 619 static void check_loader_lock_contention(Handle loader_lock, TRAPS); 620 static bool is_parallelCapable(Handle class_loader); 621 static bool is_parallelDefine(Handle class_loader); 622 623 static klassOop find_shared_class(Symbol* class_name); 624 625 // Setup link to hierarchy 626 static void add_to_hierarchy(instanceKlassHandle k, TRAPS); 627 628private: 629 // We pass in the hashtable index so we can calculate it outside of 630 // the SystemDictionary_lock. 631 632 // Basic find on loaded classes 633 static klassOop find_class(int index, unsigned int hash, 634 Symbol* name, Handle loader); 635 static klassOop find_class(Symbol* class_name, Handle class_loader); 636 637 // Basic find on classes in the midst of being loaded 638 static Symbol* find_placeholder(Symbol* name, Handle loader); 639 640 // Updating entry in dictionary 641 // Add a completely loaded class 642 static void add_klass(int index, Symbol* class_name, 643 Handle class_loader, KlassHandle obj); 644 645 // Add a placeholder for a class being loaded 646 static void add_placeholder(int index, 647 Symbol* class_name, 648 Handle class_loader); 649 static void remove_placeholder(int index, 650 Symbol* class_name, 651 Handle class_loader); 652 653 // Performs cleanups after resolve_super_or_fail. This typically needs 654 // to be called on failure. 655 // Won't throw, but can block. 656 static void resolution_cleanups(Symbol* class_name, 657 Handle class_loader, 658 TRAPS); 659 660 // Initialization 661 static void initialize_preloaded_classes(TRAPS); 662 663 // Class loader constraints 664 static void check_constraints(int index, unsigned int hash, 665 instanceKlassHandle k, Handle loader, 666 bool defining, TRAPS); 667 static void update_dictionary(int d_index, unsigned int d_hash, 668 int p_index, unsigned int p_hash, 669 instanceKlassHandle k, Handle loader, TRAPS); 670 671 // Variables holding commonly used klasses (preloaded) 672 static klassOop _well_known_klasses[]; 673 674 // Lazily loaded klasses 675 static volatile klassOop _abstract_ownable_synchronizer_klass; 676 677 // table of box klasses (int_klass, etc.) 678 static klassOop _box_klasses[T_VOID+1]; 679 680 static oop _java_system_loader; 681 682 static bool _has_loadClassInternal; 683 static bool _has_checkPackageAccess; 684}; 685 686class SystemDictionaryHandles : AllStatic { 687public: 688 #define WK_KLASS_HANDLE_DECLARE(name, ignore_symbol, option) \ 689 static KlassHandle name() { \ 690 SystemDictionary::name(); \ 691 klassOop* loc = &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]; \ 692 return KlassHandle(loc, true); \ 693 } 694 WK_KLASSES_DO(WK_KLASS_HANDLE_DECLARE); 695 #undef WK_KLASS_HANDLE_DECLARE 696 697 static KlassHandle box_klass(BasicType t); 698}; 699 700#endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP 701