1 /*
   2  * Copyright (c) 1997, 2019, 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_CLASSFILE_SYSTEMDICTIONARY_HPP
  26 #define SHARE_CLASSFILE_SYSTEMDICTIONARY_HPP
  27 
  28 #include "classfile/classLoader.hpp"
  29 #include "jvmci/systemDictionary_jvmci.hpp"
  30 #include "oops/fieldStreams.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 
  38 // The dictionary in each ClassLoaderData stores all loaded classes, either
  39 // initiatied by its class loader or defined by its class loader:
  40 //
  41 //   class loader -> ClassLoaderData -> [class, protection domain set]
  42 //
  43 // Classes are loaded lazily. The default VM class loader is
  44 // represented as NULL.
  45 
  46 // The underlying data structure is an open hash table (Dictionary) per
  47 // ClassLoaderData with a fixed number of buckets. During loading the
  48 // class loader object is locked, (for the VM loader a private lock object is used).
  49 // The global SystemDictionary_lock is held for all additions into the ClassLoaderData
  50 // dictionaries.  TODO: fix lock granularity so that class loading can
  51 // be done concurrently, but only by different loaders.
  52 //
  53 // During loading a placeholder (name, loader) is temporarily placed in
  54 // a side data structure, and is used to detect ClassCircularityErrors
  55 // and to perform verification during GC.  A GC can occur in the midst
  56 // of class loading, as we call out to Java, have to take locks, etc.
  57 //
  58 // When class loading is finished, a new entry is added to the dictionary
  59 // of the class loader and the placeholder is removed. Note that the protection
  60 // domain field of the dictionary entry has not yet been filled in when
  61 // the "real" dictionary entry is created.
  62 //
  63 // Clients of this class who are interested in finding if a class has
  64 // been completely loaded -- not classes in the process of being loaded --
  65 // can read the dictionary unlocked. This is safe because
  66 //    - entries are only deleted at safepoints
  67 //    - readers cannot come to a safepoint while actively examining
  68 //         an entry  (an entry cannot be deleted from under a reader)
  69 //    - entries must be fully formed before they are available to concurrent
  70 //         readers (we must ensure write ordering)
  71 //
  72 // Note that placeholders are deleted at any time, as they are removed
  73 // when a class is completely loaded. Therefore, readers as well as writers
  74 // of placeholders must hold the SystemDictionary_lock.
  75 //
  76 
  77 class ClassFileStream;
  78 class Dictionary;
  79 class PlaceholderTable;
  80 class LoaderConstraintTable;
  81 template <MEMFLAGS F> class HashtableBucket;
  82 class ResolutionErrorTable;
  83 class SymbolPropertyTable;
  84 class ProtectionDomainCacheTable;
  85 class ProtectionDomainCacheEntry;
  86 class GCTimer;
  87 class OopStorage;
  88 
  89 #define WK_KLASS_ENUM_NAME(kname)    kname##_knum
  90 
  91 // Certain classes, such as java.lang.Object and java.lang.String,
  92 // are "well-known", in the sense that no class loader is allowed
  93 // to provide a different definition.
  94 //
  95 // Each well-known class has a short klass name (like object_klass),
  96 // and a vmSymbol name (like java_lang_Object).
  97 //
  98 // The order of these definitions is significant: the classes are
  99 // resolved during early VM start-up by resolve_well_known_classes
 100 // in this order. Changing the order may require careful restructuring
 101 // of the VM start-up sequence.
 102 //
 103 #define WK_KLASSES_DO(do_klass)                                                                                 \
 104   /* well-known classes */                                                                                      \
 105   do_klass(Object_klass,                                java_lang_Object                                      ) \
 106   do_klass(String_klass,                                java_lang_String                                      ) \
 107   do_klass(Class_klass,                                 java_lang_Class                                       ) \
 108   do_klass(Cloneable_klass,                             java_lang_Cloneable                                   ) \
 109   do_klass(ClassLoader_klass,                           java_lang_ClassLoader                                 ) \
 110   do_klass(Serializable_klass,                          java_io_Serializable                                  ) \
 111   do_klass(System_klass,                                java_lang_System                                      ) \
 112   do_klass(Throwable_klass,                             java_lang_Throwable                                   ) \
 113   do_klass(Error_klass,                                 java_lang_Error                                       ) \
 114   do_klass(ThreadDeath_klass,                           java_lang_ThreadDeath                                 ) \
 115   do_klass(Exception_klass,                             java_lang_Exception                                   ) \
 116   do_klass(RuntimeException_klass,                      java_lang_RuntimeException                            ) \
 117   do_klass(SecurityManager_klass,                       java_lang_SecurityManager                             ) \
 118   do_klass(ProtectionDomain_klass,                      java_security_ProtectionDomain                        ) \
 119   do_klass(AccessControlContext_klass,                  java_security_AccessControlContext                    ) \
 120   do_klass(AccessController_klass,                      java_security_AccessController                        ) \
 121   do_klass(SecureClassLoader_klass,                     java_security_SecureClassLoader                       ) \
 122   do_klass(ClassNotFoundException_klass,                java_lang_ClassNotFoundException                      ) \
 123   do_klass(NoClassDefFoundError_klass,                  java_lang_NoClassDefFoundError                        ) \
 124   do_klass(LinkageError_klass,                          java_lang_LinkageError                                ) \
 125   do_klass(ClassCastException_klass,                    java_lang_ClassCastException                          ) \
 126   do_klass(ArrayStoreException_klass,                   java_lang_ArrayStoreException                         ) \
 127   do_klass(VirtualMachineError_klass,                   java_lang_VirtualMachineError                         ) \
 128   do_klass(OutOfMemoryError_klass,                      java_lang_OutOfMemoryError                            ) \
 129   do_klass(StackOverflowError_klass,                    java_lang_StackOverflowError                          ) \
 130   do_klass(IllegalMonitorStateException_klass,          java_lang_IllegalMonitorStateException                ) \
 131   do_klass(Reference_klass,                             java_lang_ref_Reference                               ) \
 132                                                                                                                 \
 133   /* ref klasses and set reference types */                                                                     \
 134   do_klass(SoftReference_klass,                         java_lang_ref_SoftReference                           ) \
 135   do_klass(WeakReference_klass,                         java_lang_ref_WeakReference                           ) \
 136   do_klass(FinalReference_klass,                        java_lang_ref_FinalReference                          ) \
 137   do_klass(PhantomReference_klass,                      java_lang_ref_PhantomReference                        ) \
 138   do_klass(Finalizer_klass,                             java_lang_ref_Finalizer                               ) \
 139                                                                                                                 \
 140   do_klass(Thread_klass,                                java_lang_Thread                                      ) \
 141   do_klass(ThreadGroup_klass,                           java_lang_ThreadGroup                                 ) \
 142   do_klass(Properties_klass,                            java_util_Properties                                  ) \
 143   do_klass(Module_klass,                                java_lang_Module                                      ) \
 144   do_klass(reflect_AccessibleObject_klass,              java_lang_reflect_AccessibleObject                    ) \
 145   do_klass(reflect_Field_klass,                         java_lang_reflect_Field                               ) \
 146   do_klass(reflect_Parameter_klass,                     java_lang_reflect_Parameter                           ) \
 147   do_klass(reflect_Method_klass,                        java_lang_reflect_Method                              ) \
 148   do_klass(reflect_Constructor_klass,                   java_lang_reflect_Constructor                         ) \
 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                             ) \
 153   do_klass(reflect_MethodAccessorImpl_klass,            reflect_MethodAccessorImpl                            ) \
 154   do_klass(reflect_ConstructorAccessorImpl_klass,       reflect_ConstructorAccessorImpl                       ) \
 155   do_klass(reflect_DelegatingClassLoader_klass,         reflect_DelegatingClassLoader                         ) \
 156   do_klass(reflect_ConstantPool_klass,                  reflect_ConstantPool                                  ) \
 157   do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, reflect_UnsafeStaticFieldAccessorImpl                 ) \
 158   do_klass(reflect_CallerSensitive_klass,               reflect_CallerSensitive                               ) \
 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                   ) \
 162   do_klass(MethodHandle_klass,                          java_lang_invoke_MethodHandle                         ) \
 163   do_klass(VarHandle_klass,                             java_lang_invoke_VarHandle                            ) \
 164   do_klass(MemberName_klass,                            java_lang_invoke_MemberName                           ) \
 165   do_klass(ResolvedMethodName_klass,                    java_lang_invoke_ResolvedMethodName                   ) \
 166   do_klass(MethodHandleNatives_klass,                   java_lang_invoke_MethodHandleNatives                  ) \
 167   do_klass(LambdaForm_klass,                            java_lang_invoke_LambdaForm                           ) \
 168   do_klass(MethodType_klass,                            java_lang_invoke_MethodType                           ) \
 169   do_klass(BootstrapMethodError_klass,                  java_lang_BootstrapMethodError                        ) \
 170   do_klass(CallSite_klass,                              java_lang_invoke_CallSite                             ) \
 171   do_klass(Context_klass,                               java_lang_invoke_MethodHandleNatives_CallSiteContext  ) \
 172   do_klass(ConstantCallSite_klass,                      java_lang_invoke_ConstantCallSite                     ) \
 173   do_klass(MutableCallSite_klass,                       java_lang_invoke_MutableCallSite                      ) \

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