1 /*
   2  * Copyright (c) 1997, 2018, 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/classLoader.hpp"
  29 #include "classfile/systemDictionary_ext.hpp"
  30 #include "jvmci/systemDictionary_jvmci.hpp"
  31 #include "oops/objArrayOop.hpp"
  32 #include "oops/symbol.hpp"
  33 #include "runtime/java.hpp"
  34 #include "runtime/reflectionUtils.hpp"
  35 #include "runtime/signature.hpp"
  36 #include "utilities/hashtable.hpp"
  37 #include "utilities/hashtable.inline.hpp"
  38 
  39 // The dictionary in each ClassLoaderData stores all loaded classes, either
  40 // initiatied by its class loader or defined by its class loader:
  41 //
  42 //   class loader -> ClassLoaderData -> [class, protection domain set]
  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 (Dictionary) per
  48 // ClassLoaderData with a fixed number of buckets. During loading the
  49 // class loader object is locked, (for the VM loader a private lock object is used).
  50 // The global SystemDictionary_lock is held for all additions into the ClassLoaderData
  51 // dictionaries.  TODO: fix lock granularity so that class loading can
  52 // be done concurrently, but only by different loaders.
  53 //
  54 // During loading a placeholder (name, loader) is temporarily placed in
  55 // a side data structure, and is used to detect ClassCircularityErrors
  56 // and to perform verification during GC.  A GC can occur in the midst
  57 // of class loading, as we call out to Java, have to take locks, etc.
  58 //
  59 // When class loading is finished, a new entry is added to the dictionary
  60 // of the class loader and the placeholder is removed. Note that the protection
  61 // domain field of the dictionary entry has not yet been filled in when
  62 // the "real" dictionary entry is created.
  63 //
  64 // Clients of this class who are interested in finding if a class has
  65 // been completely loaded -- not classes in the process of being loaded --
  66 // can read the dictionary unlocked. This is safe because
  67 //    - entries are only deleted at safepoints
  68 //    - readers cannot come to a safepoint while actively examining
  69 //         an entry  (an entry cannot be deleted from under a reader)
  70 //    - entries must be fully formed before they are available to concurrent
  71 //         readers (we must ensure write ordering)
  72 //
  73 // Note that placeholders are deleted at any time, as they are removed
  74 // when a class is completely loaded. Therefore, readers as well as writers
  75 // of placeholders must hold the SystemDictionary_lock.
  76 //
  77 
  78 class ClassFileStream;
  79 class Dictionary;
  80 class PlaceholderTable;
  81 class LoaderConstraintTable;
  82 template <MEMFLAGS F> class HashtableBucket;
  83 class ResolutionErrorTable;
  84 class SymbolPropertyTable;
  85 class ProtectionDomainCacheTable;
  86 class ProtectionDomainCacheEntry;
  87 class GCTimer;
  88 
  89 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
  90 // They are all "well-known", in the sense that no class loader is allowed
  91 // to provide a different definition.
  92 //
  93 // These klasses must all have names defined in vmSymbols.
  94 
  95 #define WK_KLASS_ENUM_NAME(kname)    kname##_knum
  96 
  97 // Each well-known class has a short klass name (like object_klass),
  98 // a vmSymbol name (like java_lang_Object), and a flag word
  99 // that makes some minor distinctions, like whether the klass
 100 // is preloaded, optional, release-specific, etc.
 101 // The order of these definitions is significant; it is the order in which
 102 // preloading is actually performed by initialize_preloaded_classes.
 103 
 104 #define WK_KLASSES_DO(do_klass)                                                                                          \
 105   /* well-known classes */                                                                                               \
 106   do_klass(Object_klass,                                java_lang_Object,                          Pre                 ) \
 107   do_klass(String_klass,                                java_lang_String,                          Pre                 ) \
 108   do_klass(Class_klass,                                 java_lang_Class,                           Pre                 ) \
 109   do_klass(Cloneable_klass,                             java_lang_Cloneable,                       Pre                 ) \
 110   do_klass(ClassLoader_klass,                           java_lang_ClassLoader,                     Pre                 ) \
 111   do_klass(Serializable_klass,                          java_io_Serializable,                      Pre                 ) \
 112   do_klass(System_klass,                                java_lang_System,                          Pre                 ) \
 113   do_klass(Throwable_klass,                             java_lang_Throwable,                       Pre                 ) \
 114   do_klass(Error_klass,                                 java_lang_Error,                           Pre                 ) \
 115   do_klass(ThreadDeath_klass,                           java_lang_ThreadDeath,                     Pre                 ) \
 116   do_klass(Exception_klass,                             java_lang_Exception,                       Pre                 ) \
 117   do_klass(RuntimeException_klass,                      java_lang_RuntimeException,                Pre                 ) \
 118   do_klass(SecurityManager_klass,                       java_lang_SecurityManager,                 Pre                 ) \
 119   do_klass(ProtectionDomain_klass,                      java_security_ProtectionDomain,            Pre                 ) \
 120   do_klass(AccessControlContext_klass,                  java_security_AccessControlContext,        Pre                 ) \
 121   do_klass(SecureClassLoader_klass,                     java_security_SecureClassLoader,           Pre                 ) \
 122   do_klass(ClassNotFoundException_klass,                java_lang_ClassNotFoundException,          Pre                 ) \
 123   do_klass(NoClassDefFoundError_klass,                  java_lang_NoClassDefFoundError,            Pre                 ) \
 124   do_klass(LinkageError_klass,                          java_lang_LinkageError,                    Pre                 ) \
 125   do_klass(ClassCastException_klass,                    java_lang_ClassCastException,              Pre                 ) \
 126   do_klass(ArrayStoreException_klass,                   java_lang_ArrayStoreException,             Pre                 ) \
 127   do_klass(VirtualMachineError_klass,                   java_lang_VirtualMachineError,             Pre                 ) \
 128   do_klass(OutOfMemoryError_klass,                      java_lang_OutOfMemoryError,                Pre                 ) \
 129   do_klass(StackOverflowError_klass,                    java_lang_StackOverflowError,              Pre                 ) \
 130   do_klass(IllegalMonitorStateException_klass,          java_lang_IllegalMonitorStateException,    Pre                 ) \
 131   do_klass(Reference_klass,                             java_lang_ref_Reference,                   Pre                 ) \
 132                                                                                                                          \
 133   /* Preload ref klasses and set reference types */                                                                      \
 134   do_klass(SoftReference_klass,                         java_lang_ref_SoftReference,               Pre                 ) \
 135   do_klass(WeakReference_klass,                         java_lang_ref_WeakReference,               Pre                 ) \
 136   do_klass(FinalReference_klass,                        java_lang_ref_FinalReference,              Pre                 ) \
 137   do_klass(PhantomReference_klass,                      java_lang_ref_PhantomReference,            Pre                 ) \
 138   do_klass(Finalizer_klass,                             java_lang_ref_Finalizer,                   Pre                 ) \
 139                                                                                                                          \
 140   do_klass(Thread_klass,                                java_lang_Thread,                          Pre                 ) \
 141   do_klass(ThreadGroup_klass,                           java_lang_ThreadGroup,                     Pre                 ) \
 142   do_klass(Properties_klass,                            java_util_Properties,                      Pre                 ) \
 143   do_klass(Module_klass,                                java_lang_Module,                          Pre                 ) \
 144   do_klass(reflect_AccessibleObject_klass,              java_lang_reflect_AccessibleObject,        Pre                 ) \
 145   do_klass(reflect_Field_klass,                         java_lang_reflect_Field,                   Pre                 ) \
 146   do_klass(reflect_Parameter_klass,                     java_lang_reflect_Parameter,               Opt                 ) \
 147   do_klass(reflect_Method_klass,                        java_lang_reflect_Method,                  Pre                 ) \
 148   do_klass(reflect_Constructor_klass,                   java_lang_reflect_Constructor,             Pre                 ) \
 149                                                                                                                          \




 150   /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */                              \
 151   /* It's okay if this turns out to be NULL in non-1.4 JDKs. */                                                          \
 152   do_klass(reflect_MagicAccessorImpl_klass,             reflect_MagicAccessorImpl,                 Opt                 ) \
 153   do_klass(reflect_MethodAccessorImpl_klass,            reflect_MethodAccessorImpl,                Pre                 ) \
 154   do_klass(reflect_ConstructorAccessorImpl_klass,       reflect_ConstructorAccessorImpl,           Pre                 ) \
 155   do_klass(reflect_DelegatingClassLoader_klass,         reflect_DelegatingClassLoader,             Opt                 ) \
 156   do_klass(reflect_ConstantPool_klass,                  reflect_ConstantPool,                      Opt                 ) \
 157   do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, reflect_UnsafeStaticFieldAccessorImpl,     Opt                 ) \
 158   do_klass(reflect_CallerSensitive_klass,               reflect_CallerSensitive,                   Opt                 ) \
 159                                                                                                                          \
 160   /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */                                            \
 161   do_klass(DirectMethodHandle_klass,                    java_lang_invoke_DirectMethodHandle,       Opt                 ) \
 162   do_klass(MethodHandle_klass,                          java_lang_invoke_MethodHandle,             Pre                 ) \
 163   do_klass(VarHandle_klass,                             java_lang_invoke_VarHandle,                Pre                 ) \
 164   do_klass(MemberName_klass,                            java_lang_invoke_MemberName,               Pre                 ) \
 165   do_klass(ResolvedMethodName_klass,                    java_lang_invoke_ResolvedMethodName,       Pre                 ) \
 166   do_klass(MethodHandleNatives_klass,                   java_lang_invoke_MethodHandleNatives,      Pre                 ) \
 167   do_klass(LambdaForm_klass,                            java_lang_invoke_LambdaForm,               Opt                 ) \
 168   do_klass(MethodType_klass,                            java_lang_invoke_MethodType,               Pre                 ) \
 169   do_klass(BootstrapMethodError_klass,                  java_lang_BootstrapMethodError,            Pre                 ) \
 170   do_klass(CallSite_klass,                              java_lang_invoke_CallSite,                 Pre                 ) \
 171   do_klass(Context_klass,                               java_lang_invoke_MethodHandleNatives_CallSiteContext, Pre      ) \
 172   do_klass(ConstantCallSite_klass,                      java_lang_invoke_ConstantCallSite,         Pre                 ) \
 173   do_klass(MutableCallSite_klass,                       java_lang_invoke_MutableCallSite,          Pre                 ) \
 174   do_klass(VolatileCallSite_klass,                      java_lang_invoke_VolatileCallSite,         Pre                 ) \
 175   /* Note: MethodHandle must be first, and VolatileCallSite last in group */                                             \
 176                                                                                                                          \
 177   do_klass(AssertionStatusDirectives_klass,             java_lang_AssertionStatusDirectives,       Pre                 ) \
 178   do_klass(StringBuffer_klass,                          java_lang_StringBuffer,                    Pre                 ) \
 179   do_klass(StringBuilder_klass,                         java_lang_StringBuilder,                   Pre                 ) \
 180   do_klass(internal_Unsafe_klass,                       jdk_internal_misc_Unsafe,                  Pre                 ) \
 181   do_klass(module_Modules_klass,                        jdk_internal_module_Modules,               Pre                 ) \
 182                                                                                                                          \
 183   /* support for CDS */                                                                                                  \
 184   do_klass(ByteArrayInputStream_klass,                  java_io_ByteArrayInputStream,              Pre                 ) \
 185   do_klass(File_klass,                                  java_io_File,                              Pre                 ) \
 186   do_klass(URL_klass,                                   java_net_URL,                              Pre                 ) \
 187   do_klass(Jar_Manifest_klass,                          java_util_jar_Manifest,                    Pre                 ) \
 188   do_klass(jdk_internal_loader_ClassLoaders_AppClassLoader_klass,      jdk_internal_loader_ClassLoaders_AppClassLoader,       Pre ) \
 189   do_klass(jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass, jdk_internal_loader_ClassLoaders_PlatformClassLoader,  Pre ) \
 190   do_klass(CodeSource_klass,                            java_security_CodeSource,                  Pre                 ) \
 191   do_klass(ParseUtil_klass,                             sun_net_www_ParseUtil,                     Pre                 ) \
 192                                                                                                                          \
 193   do_klass(StackTraceElement_klass,                     java_lang_StackTraceElement,               Opt                 ) \
 194                                                                                                                          \
 195   /* It's okay if this turns out to be NULL in non-1.4 JDKs. */                                                          \
 196   do_klass(nio_Buffer_klass,                            java_nio_Buffer,                           Opt                 ) \
 197                                                                                                                          \
 198   /* Stack Walking */                                                                                                    \
 199   do_klass(StackWalker_klass,                           java_lang_StackWalker,                     Opt                 ) \
 200   do_klass(AbstractStackWalker_klass,                   java_lang_StackStreamFactory_AbstractStackWalker, Opt          ) \
 201   do_klass(StackFrameInfo_klass,                        java_lang_StackFrameInfo,                  Opt                 ) \
 202   do_klass(LiveStackFrameInfo_klass,                    java_lang_LiveStackFrameInfo,              Opt                 ) \
 203                                                                                                                          \
 204   /* Preload boxing klasses */                                                                                           \
 205   do_klass(Boolean_klass,                               java_lang_Boolean,                         Pre                 ) \
 206   do_klass(Character_klass,                             java_lang_Character,                       Pre                 ) \
 207   do_klass(Float_klass,                                 java_lang_Float,                           Pre                 ) \
 208   do_klass(Double_klass,                                java_lang_Double,                          Pre                 ) \
 209   do_klass(Byte_klass,                                  java_lang_Byte,                            Pre                 ) \
 210   do_klass(Short_klass,                                 java_lang_Short,                           Pre                 ) \
 211   do_klass(Integer_klass,                               java_lang_Integer,                         Pre                 ) \
 212   do_klass(Long_klass,                                  java_lang_Long,                            Pre                 ) \
 213                                                                                                                          \
 214   /* Extensions */                                                                                                       \
 215   WK_KLASSES_DO_EXT(do_klass)                                                                                            \
 216   /* JVMCI classes. These are loaded on-demand. */                                                                       \
 217   JVMCI_WK_KLASSES_DO(do_klass)                                                                                          \
 218                                                                                                                          \
 219   /*end*/
 220 
 221 
 222 class SystemDictionary : AllStatic {
 223   friend class VMStructs;
 224   friend class SystemDictionaryHandles;
 225   friend class SharedClassUtil;
 226 
 227  public:
 228   enum WKID {
 229     NO_WKID = 0,
 230 
 231     #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
 232     WK_KLASSES_DO(WK_KLASS_ENUM)
 233     #undef WK_KLASS_ENUM
 234 
 235     WKID_LIMIT,
 236 
 237 #if INCLUDE_JVMCI
 238     FIRST_JVMCI_WKID = WK_KLASS_ENUM_NAME(JVMCI_klass),
 239     LAST_JVMCI_WKID  = WK_KLASS_ENUM_NAME(Value_klass),
 240 #endif
 241 
 242     FIRST_WKID = NO_WKID + 1
 243   };
 244 
 245   enum InitOption {
 246     Pre,                        // preloaded; error if not present
 247 
 248     // Order is significant.  Options before this point require resolve_or_fail.
 249     // Options after this point will use resolve_or_null instead.
 250 
 251     Opt,                        // preload tried; NULL if not present
 252 #if INCLUDE_JVMCI
 253     Jvmci,                      // preload tried; error if not present if JVMCI enabled
 254 #endif
 255     OPTION_LIMIT,
 256     CEIL_LG_OPTION_LIMIT = 2    // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
 257   };
 258 
 259 
 260   // Returns a class with a given class name and class loader.  Loads the
 261   // class if needed. If not found a NoClassDefFoundError or a
 262   // ClassNotFoundException is thrown, depending on the value on the
 263   // throw_error flag.  For most uses the throw_error argument should be set
 264   // to true.
 265 
 266   static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
 267   // Convenient call for null loader and protection domain.
 268   static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
 269 protected:
 270   // handle error translation for resolve_or_null results
 271   static Klass* handle_resolution_exception(Symbol* class_name, bool throw_error, Klass* klass, TRAPS);
 272 
 273 public:
 274 
 275   // Returns a class with a given class name and class loader.
 276   // Loads the class if needed. If not found NULL is returned.
 277   static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
 278   // Version with null loader and protection domain
 279   static Klass* resolve_or_null(Symbol* class_name, TRAPS);
 280 
 281   // Resolve a superclass or superinterface. Called from ClassFileParser,
 282   // parse_interfaces, resolve_instance_class_or_null, load_shared_class
 283   // "child_name" is the class whose super class or interface is being resolved.
 284   static Klass* resolve_super_or_fail(Symbol* child_name,
 285                                       Symbol* class_name,
 286                                       Handle class_loader,
 287                                       Handle protection_domain,
 288                                       bool is_superclass,
 289                                       TRAPS);
 290 
 291   // Parse new stream. This won't update the dictionary or
 292   // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
 293   // Also used by Unsafe_DefineAnonymousClass
 294   static InstanceKlass* parse_stream(Symbol* class_name,
 295                                      Handle class_loader,
 296                                      Handle protection_domain,
 297                                      ClassFileStream* st,
 298                                      TRAPS) {
 299     return parse_stream(class_name,
 300                         class_loader,
 301                         protection_domain,
 302                         st,
 303                         NULL, // host klass
 304                         NULL, // cp_patches
 305                         THREAD);
 306   }
 307   static InstanceKlass* parse_stream(Symbol* class_name,
 308                                      Handle class_loader,
 309                                      Handle protection_domain,
 310                                      ClassFileStream* st,
 311                                      const InstanceKlass* host_klass,
 312                                      GrowableArray<Handle>* cp_patches,
 313                                      TRAPS);
 314 
 315   // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
 316   static InstanceKlass* resolve_from_stream(Symbol* class_name,
 317                                             Handle class_loader,
 318                                             Handle protection_domain,
 319                                             ClassFileStream* st,
 320                                             TRAPS);
 321 
 322   // Lookup an already loaded class. If not found NULL is returned.
 323   static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
 324 
 325   // Lookup an already loaded instance or array class.
 326   // Do not make any queries to class loaders; consult only the cache.
 327   // If not found NULL is returned.
 328   static Klass* find_instance_or_array_klass(Symbol* class_name,
 329                                                Handle class_loader,
 330                                                Handle protection_domain,
 331                                                TRAPS);
 332 
 333   // Lookup an instance or array class that has already been loaded
 334   // either into the given class loader, or else into another class
 335   // loader that is constrained (via loader constraints) to produce
 336   // a consistent class.  Do not take protection domains into account.
 337   // Do not make any queries to class loaders; consult only the cache.
 338   // Return NULL if the class is not found.
 339   //
 340   // This function is a strict superset of find_instance_or_array_klass.
 341   // This function (the unchecked version) makes a conservative prediction
 342   // of the result of the checked version, assuming successful lookup.
 343   // If both functions return non-null, they must return the same value.
 344   // Also, the unchecked version may sometimes be non-null where the
 345   // checked version is null.  This can occur in several ways:
 346   //   1. No query has yet been made to the class loader.
 347   //   2. The class loader was queried, but chose not to delegate.
 348   //   3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
 349   //   4. Loading was attempted, but there was a linkage error of some sort.
 350   // In all of these cases, the loader constraints on this type are
 351   // satisfied, and it is safe for classes in the given class loader
 352   // to manipulate strongly-typed values of the found class, subject
 353   // to local linkage and access checks.
 354   static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
 355                                                            Handle class_loader,
 356                                                            TRAPS);
 357 
 358   static void classes_do(MetaspaceClosure* it);
 359   // Iterate over all methods in all klasses
 360 
 361   static void methods_do(void f(Method*));
 362 
 363   // Garbage collection support
 364 
 365   // This method applies "blk->do_oop" to all the pointers to "system"
 366   // classes and loaders.
 367   static void always_strong_oops_do(OopClosure* blk);
 368 
 369   // Unload (that is, break root links to) all unmarked classes and
 370   // loaders.  Returns "true" iff something was unloaded.
 371   static bool do_unloading(BoolObjectClosure* is_alive,
 372                            GCTimer* gc_timer,
 373                            bool do_cleaning = true);
 374 
 375   // Used by DumpSharedSpaces only to remove classes that failed verification
 376   static void remove_classes_in_error_state();
 377 
 378   static int calculate_systemdictionary_size(int loadedclasses);
 379 
 380   // Applies "f->do_oop" to all root oops in the system dictionary.
 381   static void oops_do(OopClosure* f);
 382   static void roots_oops_do(OopClosure* strong, OopClosure* weak);
 383 
 384   // System loader lock
 385   static oop system_loader_lock()           { return _system_loader_lock_obj; }
 386 
 387 public:
 388   // Sharing support.
 389   static void reorder_dictionary_for_sharing() NOT_CDS_RETURN;
 390   static void combine_shared_dictionaries();
 391   static size_t count_bytes_for_buckets();
 392   static size_t count_bytes_for_table();
 393   static void copy_buckets(char* top, char* end);
 394   static void copy_table(char* top, char* end);
 395   static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
 396                                     int number_of_entries);
 397   // Printing
 398   static void print() { return print_on(tty); }
 399   static void print_on(outputStream* st);
 400   static void print_shared(outputStream* st);
 401   static void dump(outputStream* st, bool verbose);
 402 
 403   // Monotonically increasing counter which grows as classes are
 404   // loaded or modifications such as hot-swapping or setting/removing
 405   // of breakpoints are performed
 406   static inline int number_of_modifications()     { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
 407   // Needed by evolution and breakpoint code
 408   static inline void notice_modification()        { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications;      }
 409 
 410   // Verification
 411   static void verify();
 412 
 413   // Initialization
 414   static void initialize(TRAPS);
 415 
 416   // Checked fast access to commonly used classes - mostly preloaded
 417   static InstanceKlass* check_klass(InstanceKlass* k) {
 418     assert(k != NULL, "klass not loaded");
 419     return k;
 420   }
 421 
 422   static InstanceKlass* check_klass_Pre(InstanceKlass* k) { return check_klass(k); }
 423   static InstanceKlass* check_klass_Opt(InstanceKlass* k) { return k; }
 424 
 425   JVMCI_ONLY(static InstanceKlass* check_klass_Jvmci(InstanceKlass* k) { return k; })
 426 
 427   static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
 428   static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
 429   static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
 430     int limit = (int)end_id + 1;
 431     initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
 432   }
 433 
 434 public:
 435   #define WK_KLASS_DECLARE(name, symbol, option) \
 436     static InstanceKlass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
 437     static InstanceKlass** name##_addr() {                                                                       \
 438       return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)];           \
 439     }
 440   WK_KLASSES_DO(WK_KLASS_DECLARE);
 441   #undef WK_KLASS_DECLARE
 442 
 443   static InstanceKlass* well_known_klass(WKID id) {
 444     assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
 445     return _well_known_klasses[id];
 446   }
 447 
 448   static InstanceKlass** well_known_klass_addr(WKID id) {
 449     assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
 450     return &_well_known_klasses[id];
 451   }
 452   static void well_known_klasses_do(MetaspaceClosure* it);
 453 
 454   // Local definition for direct access to the private array:
 455   #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
 456 
 457   static InstanceKlass* box_klass(BasicType t) {
 458     assert((uint)t < T_VOID+1, "range check");
 459     return check_klass(_box_klasses[t]);
 460   }
 461   static BasicType box_klass_type(Klass* k);  // inverse of box_klass
 462 
 463   // methods returning lazily loaded klasses
 464   // The corresponding method to load the class must be called before calling them.
 465   static InstanceKlass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
 466 
 467   static void load_abstract_ownable_synchronizer_klass(TRAPS);
 468 
 469 protected:
 470   // Tells whether ClassLoader.loadClassInternal is present
 471   static bool has_loadClassInternal()       { return _has_loadClassInternal; }
 472 
 473   // Returns the class loader data to be used when looking up/updating the
 474   // system dictionary.
 475   static ClassLoaderData *class_loader_data(Handle class_loader) {
 476     return ClassLoaderData::class_loader_data(class_loader());
 477   }
 478 
 479 public:
 480   // Tells whether ClassLoader.checkPackageAccess is present
 481   static bool has_checkPackageAccess()      { return _has_checkPackageAccess; }
 482 
 483   static bool Parameter_klass_loaded()      { return WK_KLASS(reflect_Parameter_klass) != NULL; }
 484   static bool Class_klass_loaded()          { return WK_KLASS(Class_klass) != NULL; }
 485   static bool Cloneable_klass_loaded()      { return WK_KLASS(Cloneable_klass) != NULL; }
 486   static bool Object_klass_loaded()         { return WK_KLASS(Object_klass) != NULL; }
 487   static bool ClassLoader_klass_loaded()    { return WK_KLASS(ClassLoader_klass) != NULL; }
 488 
 489   // Returns java system loader
 490   static oop java_system_loader();
 491 
 492   // Returns java platform loader
 493   static oop java_platform_loader();
 494 
 495   // Compute the java system and platform loaders
 496   static void compute_java_loaders(TRAPS);
 497 
 498   // Register a new class loader
 499   static ClassLoaderData* register_loader(Handle class_loader, TRAPS);
 500 protected:
 501   // Mirrors for primitive classes (created eagerly)
 502   static oop check_mirror(oop m) {
 503     assert(m != NULL, "mirror not initialized");
 504     return m;
 505   }
 506 
 507 public:
 508   // Note:  java_lang_Class::primitive_type is the inverse of java_mirror
 509 
 510   // Check class loader constraints
 511   static bool add_loader_constraint(Symbol* name, Handle loader1,
 512                                     Handle loader2, TRAPS);
 513   static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
 514                                          Handle loader2, bool is_method, TRAPS);
 515 
 516   // JSR 292
 517   // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
 518   // (asks Java to compute it if necessary, except in a compiler thread)
 519   static methodHandle find_method_handle_invoker(Klass* klass,
 520                                                  Symbol* name,
 521                                                  Symbol* signature,
 522                                                  Klass* accessing_klass,
 523                                                  Handle *appendix_result,
 524                                                  Handle *method_type_result,
 525                                                  TRAPS);
 526   // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
 527   // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
 528   static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
 529                                                    Symbol* signature,
 530                                                    TRAPS);
 531 
 532   // compute java_mirror (java.lang.Class instance) for a type ("I", "[[B", "LFoo;", etc.)
 533   // Either the accessing_klass or the CL/PD can be non-null, but not both.
 534   static Handle    find_java_mirror_for_type(Symbol* signature,
 535                                              Klass* accessing_klass,
 536                                              Handle class_loader,
 537                                              Handle protection_domain,
 538                                              SignatureStream::FailureMode failure_mode,
 539                                              TRAPS);
 540   static Handle    find_java_mirror_for_type(Symbol* signature,
 541                                              Klass* accessing_klass,
 542                                              SignatureStream::FailureMode failure_mode,
 543                                              TRAPS) {
 544     // callee will fill in CL/PD from AK, if they are needed
 545     return find_java_mirror_for_type(signature, accessing_klass, Handle(), Handle(),
 546                                      failure_mode, THREAD);
 547   }
 548 
 549 
 550   // fast short-cut for the one-character case:
 551   static oop       find_java_mirror_for_type(char signature_char);
 552 
 553   // find a java.lang.invoke.MethodType object for a given signature
 554   // (asks Java to compute it if necessary, except in a compiler thread)
 555   static Handle    find_method_handle_type(Symbol* signature,
 556                                            Klass* accessing_klass,
 557                                            TRAPS);
 558 
 559   // find a java.lang.Class object for a given signature
 560   static Handle    find_field_handle_type(Symbol* signature,
 561                                           Klass* accessing_klass,
 562                                           TRAPS);
 563 
 564   // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
 565   static Handle    link_method_handle_constant(Klass* caller,
 566                                                int ref_kind, //e.g., JVM_REF_invokeVirtual
 567                                                Klass* callee,
 568                                                Symbol* name,
 569                                                Symbol* signature,
 570                                                TRAPS);
 571 
 572   // ask Java to compute a constant by invoking a BSM given a Dynamic_info CP entry
 573   static Handle    link_dynamic_constant(Klass* caller,
 574                                          int condy_index,
 575                                          Handle bootstrap_specifier,
 576                                          Symbol* name,
 577                                          Symbol* type,
 578                                          TRAPS);
 579 
 580   // ask Java to create a dynamic call site, while linking an invokedynamic op
 581   static methodHandle find_dynamic_call_site_invoker(Klass* caller,
 582                                                      int indy_index,
 583                                                      Handle bootstrap_method,
 584                                                      Symbol* name,
 585                                                      Symbol* type,
 586                                                      Handle *appendix_result,
 587                                                      Handle *method_type_result,
 588                                                      TRAPS);
 589 
 590   // Utility for printing loader "name" as part of tracing constraints
 591   static const char* loader_name(const oop loader);
 592   static const char* loader_name(const ClassLoaderData* loader_data);
 593 
 594   // Record the error when the first attempt to resolve a reference from a constant
 595   // pool entry to a class fails.
 596   static void add_resolution_error(const constantPoolHandle& pool, int which, Symbol* error,
 597                                    Symbol* message);
 598   static void delete_resolution_error(ConstantPool* pool);
 599   static Symbol* find_resolution_error(const constantPoolHandle& pool, int which,
 600                                        Symbol** message);
 601 
 602 
 603   static ProtectionDomainCacheEntry* cache_get(Handle protection_domain);
 604 
 605  protected:
 606 
 607   enum Constants {
 608     _loader_constraint_size = 107,                     // number of entries in constraint table
 609     _resolution_error_size  = 107,                     // number of entries in resolution error table
 610     _invoke_method_size     = 139,                     // number of entries in invoke method table
 611     _shared_dictionary_size = 1009,                    // number of entries in shared dictionary
 612     _placeholder_table_size = 1009                     // number of entries in hash table for placeholders
 613   };
 614 
 615 
 616   // Static tables owned by the SystemDictionary
 617 
 618   // Hashtable holding placeholders for classes being loaded.
 619   static PlaceholderTable*       _placeholders;
 620 
 621   // Hashtable holding classes from the shared archive.
 622   static Dictionary*             _shared_dictionary;
 623 
 624   // Monotonically increasing counter which grows with
 625   // loading classes as well as hot-swapping and breakpoint setting
 626   // and removal.
 627   static int                     _number_of_modifications;
 628 
 629   // Lock object for system class loader
 630   static oop                     _system_loader_lock_obj;
 631 
 632   // Constraints on class loaders
 633   static LoaderConstraintTable*  _loader_constraints;
 634 
 635   // Resolution errors
 636   static ResolutionErrorTable*   _resolution_errors;
 637 
 638   // Invoke methods (JSR 292)
 639   static SymbolPropertyTable*    _invoke_method_table;
 640 
 641   // ProtectionDomain cache
 642   static ProtectionDomainCacheTable*   _pd_cache_table;
 643 
 644 protected:
 645   static void validate_protection_domain(InstanceKlass* klass,
 646                                          Handle class_loader,
 647                                          Handle protection_domain, TRAPS);
 648 
 649   friend class VM_PopulateDumpSharedSpace;
 650   friend class TraversePlaceholdersClosure;
 651   static Dictionary*         shared_dictionary() { return _shared_dictionary; }
 652   static PlaceholderTable*   placeholders() { return _placeholders; }
 653   static LoaderConstraintTable* constraints() { return _loader_constraints; }
 654   static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
 655   static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
 656 
 657   // Basic loading operations
 658   static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
 659   static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
 660   static InstanceKlass* handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
 661   // Wait on SystemDictionary_lock; unlocks lockObject before
 662   // waiting; relocks lockObject with correct recursion count
 663   // after waiting, but before reentering SystemDictionary_lock
 664   // to preserve lock order semantics.
 665   static void double_lock_wait(Handle lockObject, TRAPS);
 666   static void define_instance_class(InstanceKlass* k, TRAPS);
 667   static InstanceKlass* find_or_define_instance_class(Symbol* class_name,
 668                                                 Handle class_loader,
 669                                                 InstanceKlass* k, TRAPS);
 670   static bool is_shared_class_visible(Symbol* class_name, InstanceKlass* ik,
 671                                       Handle class_loader, TRAPS);
 672   static InstanceKlass* load_shared_class(InstanceKlass* ik,
 673                                           Handle class_loader,
 674                                           Handle protection_domain,
 675                                           TRAPS);
 676   static InstanceKlass* load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
 677   static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
 678   static void check_loader_lock_contention(Handle loader_lock, TRAPS);
 679   static bool is_parallelCapable(Handle class_loader);
 680   static bool is_parallelDefine(Handle class_loader);
 681 
 682 public:
 683   static InstanceKlass* load_shared_class(Symbol* class_name,
 684                                           Handle class_loader,
 685                                           TRAPS);
 686   static bool is_system_class_loader(oop class_loader);
 687   static bool is_platform_class_loader(oop class_loader);
 688   static void clear_invoke_method_table();
 689 
 690   // Returns TRUE if the method is a non-public member of class java.lang.Object.
 691   static bool is_nonpublic_Object_method(Method* m) {
 692     assert(m != NULL, "Unexpected NULL Method*");
 693     return !m->is_public() && m->method_holder() == SystemDictionary::Object_klass();
 694   }
 695 
 696 protected:
 697   static InstanceKlass* find_shared_class(Symbol* class_name);
 698 
 699   // Setup link to hierarchy
 700   static void add_to_hierarchy(InstanceKlass* k, TRAPS);
 701 
 702   // Basic find on loaded classes
 703   static InstanceKlass* find_class(unsigned int hash,
 704                                    Symbol* name, Dictionary* dictionary);
 705   static InstanceKlass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
 706 
 707   // Basic find on classes in the midst of being loaded
 708   static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
 709 
 710   // Add a placeholder for a class being loaded
 711   static void add_placeholder(int index,
 712                               Symbol* class_name,
 713                               ClassLoaderData* loader_data);
 714   static void remove_placeholder(int index,
 715                                  Symbol* class_name,
 716                                  ClassLoaderData* loader_data);
 717 
 718   // Performs cleanups after resolve_super_or_fail. This typically needs
 719   // to be called on failure.
 720   // Won't throw, but can block.
 721   static void resolution_cleanups(Symbol* class_name,
 722                                   ClassLoaderData* loader_data,
 723                                   TRAPS);
 724 
 725   // Initialization
 726   static void initialize_preloaded_classes(TRAPS);
 727 
 728   // Class loader constraints
 729   static void check_constraints(unsigned int hash,
 730                                 InstanceKlass* k, Handle loader,
 731                                 bool defining, TRAPS);
 732   static void update_dictionary(unsigned int d_hash,
 733                                 int p_index, unsigned int p_hash,
 734                                 InstanceKlass* k, Handle loader,
 735                                 TRAPS);
 736 
 737   // Variables holding commonly used klasses (preloaded)
 738   static InstanceKlass* _well_known_klasses[];
 739 
 740   // Lazily loaded klasses
 741   static InstanceKlass* volatile _abstract_ownable_synchronizer_klass;
 742 
 743   // table of box klasses (int_klass, etc.)
 744   static InstanceKlass* _box_klasses[T_VOID+1];
 745 
 746   static oop  _java_system_loader;
 747   static oop  _java_platform_loader;
 748 
 749   static bool _has_loadClassInternal;
 750   static bool _has_checkPackageAccess;
 751 };
 752 
 753 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
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