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
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  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
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  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