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 /*

  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

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  */

 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP

 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP

 #include "classfile/classFileStream.hpp"

 #include "classfile/classLoader.hpp"

 #include "oops/objArrayOop.hpp"

 #include "oops/symbol.hpp"

 #include "runtime/java.hpp"

 #include "runtime/reflectionUtils.hpp"

 #include "utilities/hashtable.hpp"

 #include "utilities/hashtable.inline.hpp"

 // The system dictionary stores all loaded classes and maps:

 //

 //   [class name,class loader] -> class   i.e.  [Symbol*,oop] -> Klass*

 //

 // Classes are loaded lazily. The default VM class loader is

 // represented as NULL.

 // The underlying data structure is an open hash table with a fixed number

 // of buckets. During loading the loader object is locked, (for the VM loader

 // a private lock object is used). Class loading can thus be done concurrently,

 // but only by different loaders.

 //

 // During loading a placeholder (name, loader) is temporarily placed in

 // a side data structure, and is used to detect ClassCircularityErrors

 // and to perform verification during GC.  A GC can occur in the midst

 // of class loading, as we call out to Java, have to take locks, etc.

 //

 // When class loading is finished, a new entry is added to the system

 // dictionary and the place holder is removed. Note that the protection

 // domain field of the system dictionary has not yet been filled in when

 // the "real" system dictionary entry is created.

 //

 // Clients of this class who are interested in finding if a class has

 // been completely loaded -- not classes in the process of being loaded --

 // can read the SystemDictionary unlocked. This is safe because

 //    - entries are only deleted at safepoints

 //    - readers cannot come to a safepoint while actively examining

 //         an entry  (an entry cannot be deleted from under a reader)

 //    - entries must be fully formed before they are available to concurrent

 //         readers (we must ensure write ordering)

 //

 // Note that placeholders are deleted at any time, as they are removed

 // when a class is completely loaded. Therefore, readers as well as writers

 // of placeholders must hold the SystemDictionary_lock.

 //

 class Dictionary;

 class PlaceholderTable;

 class LoaderConstraintTable;

 template <MEMFLAGS F> class HashtableBucket;

 class ResolutionErrorTable;

 class SymbolPropertyTable;

 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.

 // They are all "well-known", in the sense that no class loader is allowed

 // to provide a different definition.

 //

 // These klasses must all have names defined in vmSymbols.

 #define WK_KLASS_ENUM_NAME(kname)    kname##_knum

 // Each well-known class has a short klass name (like object_klass),

 // a vmSymbol name (like java_lang_Object), and a flag word

 // that makes some minor distinctions, like whether the klass

 // is preloaded, optional, release-specific, etc.

 // The order of these definitions is significant; it is the order in which

 // preloading is actually performed by initialize_preloaded_classes.

 #define WK_KLASSES_DO(do_klass)                                                                                          \

   /* well-known classes */                                                                                               \

   do_klass(Object_klass,                                java_lang_Object,                          Pre                 ) \

   do_klass(String_klass,                                java_lang_String,                          Pre                 ) \

   do_klass(Class_klass,                                 java_lang_Class,                           Pre                 ) \

   do_klass(Cloneable_klass,                             java_lang_Cloneable,                       Pre                 ) \

   do_klass(ClassLoader_klass,                           java_lang_ClassLoader,                     Pre                 ) \

   do_klass(Serializable_klass,                          java_io_Serializable,                      Pre                 ) \

   do_klass(System_klass,                                java_lang_System,                          Pre                 ) \

   do_klass(Throwable_klass,                             java_lang_Throwable,                       Pre                 ) \

   do_klass(Error_klass,                                 java_lang_Error,                           Pre                 ) \

   do_klass(ThreadDeath_klass,                           java_lang_ThreadDeath,                     Pre                 ) \

   do_klass(Exception_klass,                             java_lang_Exception,                       Pre                 ) \

   do_klass(RuntimeException_klass,                      java_lang_RuntimeException,                Pre                 ) \

   do_klass(ProtectionDomain_klass,                      java_security_ProtectionDomain,            Pre                 ) \

   do_klass(AccessControlContext_klass,                  java_security_AccessControlContext,        Pre                 ) \

   do_klass(ClassNotFoundException_klass,                java_lang_ClassNotFoundException,          Pre                 ) \

   do_klass(NoClassDefFoundError_klass,                  java_lang_NoClassDefFoundError,            Pre                 ) \

   do_klass(LinkageError_klass,                          java_lang_LinkageError,                    Pre                 ) \

   do_klass(ClassCastException_klass,                    java_lang_ClassCastException,              Pre                 ) \

   do_klass(ArrayStoreException_klass,                   java_lang_ArrayStoreException,             Pre                 ) \

   do_klass(VirtualMachineError_klass,                   java_lang_VirtualMachineError,             Pre                 ) \

   do_klass(OutOfMemoryError_klass,                      java_lang_OutOfMemoryError,                Pre                 ) \

   do_klass(StackOverflowError_klass,                    java_lang_StackOverflowError,              Pre                 ) \

   do_klass(IllegalMonitorStateException_klass,          java_lang_IllegalMonitorStateException,    Pre                 ) \

   do_klass(Reference_klass,                             java_lang_ref_Reference,                   Pre                 ) \

                                                                                                                          \

   /* Preload ref klasses and set reference types */                                                                      \

   do_klass(SoftReference_klass,                         java_lang_ref_SoftReference,               Pre                 ) \

   do_klass(WeakReference_klass,                         java_lang_ref_WeakReference,               Pre                 ) \

   do_klass(FinalReference_klass,                        java_lang_ref_FinalReference,              Pre                 ) \

   do_klass(PhantomReference_klass,                      java_lang_ref_PhantomReference,            Pre                 ) \

   do_klass(Finalizer_klass,                             java_lang_ref_Finalizer,                   Pre                 ) \

                                                                                                                          \

   do_klass(Thread_klass,                                java_lang_Thread,                          Pre                 ) \

   do_klass(ThreadGroup_klass,                           java_lang_ThreadGroup,                     Pre                 ) \

   do_klass(Properties_klass,                            java_util_Properties,                      Pre                 ) \

   do_klass(reflect_AccessibleObject_klass,              java_lang_reflect_AccessibleObject,        Pre                 ) \

   do_klass(reflect_Field_klass,                         java_lang_reflect_Field,                   Pre                 ) \

   do_klass(reflect_Parameter_klass,                     java_lang_reflect_Parameter,               Opt                 ) \

   do_klass(reflect_Method_klass,                        java_lang_reflect_Method,                  Pre                 ) \

   do_klass(reflect_Constructor_klass,                   java_lang_reflect_Constructor,             Pre                 ) \

                                                                                                                          \

   /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */                              \

   /* Universe::is_gte_jdk14x_version() is not set up by this point. */                                                   \

   /* It's okay if this turns out to be NULL in non-1.4 JDKs. */                                                          \

   do_klass(lambda_MagicLambdaImpl_klass,                java_lang_invoke_MagicLambdaImpl, Opt ) \

   do_klass(reflect_MagicAccessorImpl_klass,             sun_reflect_MagicAccessorImpl,             Opt                 ) \

   do_klass(reflect_MethodAccessorImpl_klass,            sun_reflect_MethodAccessorImpl,            Opt_Only_JDK14NewRef) \

   do_klass(reflect_ConstructorAccessorImpl_klass,       sun_reflect_ConstructorAccessorImpl,       Opt_Only_JDK14NewRef) \

   do_klass(reflect_DelegatingClassLoader_klass,         sun_reflect_DelegatingClassLoader,         Opt                 ) \

   do_klass(reflect_ConstantPool_klass,                  sun_reflect_ConstantPool,                  Opt_Only_JDK15      ) \

   do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15      ) \

                                                                                                                          \

   /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */                                            \

   do_klass(MethodHandle_klass,                          java_lang_invoke_MethodHandle,             Pre_JSR292          ) \

   do_klass(MemberName_klass,                            java_lang_invoke_MemberName,               Pre_JSR292          ) \

   do_klass(MethodHandleNatives_klass,                   java_lang_invoke_MethodHandleNatives,      Pre_JSR292          ) \

   do_klass(LambdaForm_klass,                            java_lang_invoke_LambdaForm,               Opt                 ) \

   do_klass(MethodType_klass,                            java_lang_invoke_MethodType,               Pre_JSR292          ) \

   do_klass(BootstrapMethodError_klass,                  java_lang_BootstrapMethodError,            Pre_JSR292          ) \

   do_klass(CallSite_klass,                              java_lang_invoke_CallSite,                 Pre_JSR292          ) \

   do_klass(ConstantCallSite_klass,                      java_lang_invoke_ConstantCallSite,         Pre_JSR292          ) \

   do_klass(MutableCallSite_klass,                       java_lang_invoke_MutableCallSite,          Pre_JSR292          ) \

   do_klass(VolatileCallSite_klass,                      java_lang_invoke_VolatileCallSite,         Pre_JSR292          ) \

   /* Note: MethodHandle must be first, and VolatileCallSite last in group */                                             \

                                                                                                                          \

   do_klass(StringBuffer_klass,                          java_lang_StringBuffer,                    Pre                 ) \

   do_klass(StringBuilder_klass,                         java_lang_StringBuilder,                   Pre                 ) \

                                                                                                                          \

   /* It's NULL in non-1.4 JDKs. */                                                                                       \

   do_klass(StackTraceElement_klass,                     java_lang_StackTraceElement,               Opt                 ) \

   /* Universe::is_gte_jdk14x_version() is not set up by this point. */                                                   \

   /* It's okay if this turns out to be NULL in non-1.4 JDKs. */                                                          \

   do_klass(nio_Buffer_klass,                            java_nio_Buffer,                           Opt                 ) \

                                                                                                                          \

   do_klass(DownloadManager_klass,                       sun_jkernel_DownloadManager,               Opt_Kernel          ) \

                                                                                                                          \

   do_klass(PostVMInitHook_klass,                        sun_misc_PostVMInitHook,                   Opt                 ) \

                                                                                                                          \

   /* Preload boxing klasses */                                                                                           \

   do_klass(Boolean_klass,                               java_lang_Boolean,                         Pre                 ) \

   do_klass(Character_klass,                             java_lang_Character,                       Pre                 ) \

   do_klass(Float_klass,                                 java_lang_Float,                           Pre                 ) \

   do_klass(Double_klass,                                java_lang_Double,                          Pre                 ) \

   do_klass(Byte_klass,                                  java_lang_Byte,                            Pre                 ) \

   do_klass(Short_klass,                                 java_lang_Short,                           Pre                 ) \

   do_klass(Integer_klass,                               java_lang_Integer,                         Pre                 ) \

   do_klass(Long_klass,                                  java_lang_Long,                            Pre                 ) \

   /*end*/

 class SystemDictionary : AllStatic {

   friend class VMStructs;

   friend class SystemDictionaryHandles;

  public:

   enum WKID {

     NO_WKID = 0,

     #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),

     WK_KLASSES_DO(WK_KLASS_ENUM)

     #undef WK_KLASS_ENUM

     WKID_LIMIT,

     FIRST_WKID = NO_WKID + 1

   };

   enum InitOption {

     Pre,                        // preloaded; error if not present

     Pre_JSR292,                 // preloaded if EnableInvokeDynamic

     // Order is significant.  Options before this point require resolve_or_fail.

     // Options after this point will use resolve_or_null instead.

     Opt,                        // preload tried; NULL if not present

     Opt_Only_JDK14NewRef,       // preload tried; use only with NewReflection

     Opt_Only_JDK15,             // preload tried; use only with JDK1.5+

     Opt_Kernel,                 // preload tried only #ifdef KERNEL

     OPTION_LIMIT,

     CEIL_LG_OPTION_LIMIT = 4    // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)

   };

   // Returns a class with a given class name and class loader.  Loads the

   // class if needed. If not found a NoClassDefFoundError or a

   // ClassNotFoundException is thrown, depending on the value on the

   // throw_error flag.  For most uses the throw_error argument should be set

   // to true.

   static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);

   // Convenient call for null loader and protection domain.

   static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);

 private:

   // handle error translation for resolve_or_null results

   static Klass* handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS);

 public:

   // Returns a class with a given class name and class loader.

   // Loads the class if needed. If not found NULL is returned.

   static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);

   // Version with null loader and protection domain

   static Klass* resolve_or_null(Symbol* class_name, TRAPS);

   // Resolve a superclass or superinterface. Called from ClassFileParser,

   // parse_interfaces, resolve_instance_class_or_null, load_shared_class

   // "child_name" is the class whose super class or interface is being resolved.

   static Klass* resolve_super_or_fail(Symbol* child_name,

                                         Symbol* class_name,

                                         Handle class_loader,

                                         Handle protection_domain,

                                         bool is_superclass,

                                         TRAPS);

   // Parse new stream. This won't update the system dictionary or

   // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.

   static Klass* parse_stream(Symbol* class_name,

                                Handle class_loader,

                                Handle protection_domain,

                                ClassFileStream* st,

                                TRAPS) {

     KlassHandle nullHandle;

     return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);

   }

   static Klass* parse_stream(Symbol* class_name,

                                Handle class_loader,

                                Handle protection_domain,

                                ClassFileStream* st,

                                KlassHandle host_klass,

                                GrowableArray<Handle>* cp_patches,

                                TRAPS);

   // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)

   static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader,

                                       Handle protection_domain,

                                       ClassFileStream* st, bool verify, TRAPS);

   // Lookup an already loaded class. If not found NULL is returned.

   static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);

   // Lookup an already loaded instance or array class.

   // Do not make any queries to class loaders; consult only the cache.

   // If not found NULL is returned.

   static Klass* find_instance_or_array_klass(Symbol* class_name,

                                                Handle class_loader,

                                                Handle protection_domain,

                                                TRAPS);

   // Lookup an instance or array class that has already been loaded

   // either into the given class loader, or else into another class

   // loader that is constrained (via loader constraints) to produce

   // a consistent class.  Do not take protection domains into account.

   // Do not make any queries to class loaders; consult only the cache.

   // Return NULL if the class is not found.

   //

   // This function is a strict superset of find_instance_or_array_klass.

   // This function (the unchecked version) makes a conservative prediction

   // of the result of the checked version, assuming successful lookup.

   // If both functions return non-null, they must return the same value.

   // Also, the unchecked version may sometimes be non-null where the

   // checked version is null.  This can occur in several ways:

   //   1. No query has yet been made to the class loader.

   //   2. The class loader was queried, but chose not to delegate.

   //   3. ClassLoader.checkPackageAccess rejected a proposed protection domain.

   //   4. Loading was attempted, but there was a linkage error of some sort.

   // In all of these cases, the loader constraints on this type are

   // satisfied, and it is safe for classes in the given class loader

   // to manipulate strongly-typed values of the found class, subject

   // to local linkage and access checks.

   static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,

                                                            Handle class_loader,

                                                            TRAPS);

   // Iterate over all klasses in dictionary

   //   Just the classes from defining class loaders

   static void classes_do(void f(Klass*));

   // Added for initialize_itable_for_klass to handle exceptions

   static void classes_do(void f(Klass*, TRAPS), TRAPS);

   //   All classes, and their class loaders

   static void classes_do(void f(Klass*, ClassLoaderData*));

   //   All classes, and their class loaders

   //   (added for helpers that use HandleMarks and ResourceMarks)

   static void classes_do(void f(Klass*, ClassLoaderData*, TRAPS), TRAPS);

   // All entries in the placeholder table and their class loaders

   static void placeholders_do(void f(Symbol*));

   // Iterate over all methods in all klasses in dictionary

   static void methods_do(void f(Method*));

   // Garbage collection support

   // This method applies "blk->do_oop" to all the pointers to "system"

   // classes and loaders.

   static void always_strong_oops_do(OopClosure* blk);

   static void always_strong_classes_do(KlassClosure* closure);

   // Unload (that is, break root links to) all unmarked classes and

   // loaders.  Returns "true" iff something was unloaded.

   static bool do_unloading(BoolObjectClosure* is_alive);

   static int calculate_systemdictionary_size(int loadedclasses);

   // Applies "f->do_oop" to all root oops in the system dictionary.

   static void oops_do(OopClosure* f);

   // System loader lock

   static oop system_loader_lock()           { return _system_loader_lock_obj; }

 private:

   // Extended Redefine classes support (tbi)

   static void preloaded_classes_do(KlassClosure* f);

   static void lazily_loaded_classes_do(KlassClosure* f);

 public:

   // Sharing support.

   static void reorder_dictionary();

   static void copy_buckets(char** top, char* end);

   static void copy_table(char** top, char* end);

   static void reverse();

   static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,

                                     int number_of_entries);

   // Printing

   static void print()                   PRODUCT_RETURN;

   static void print_class_statistics()  PRODUCT_RETURN;

   static void print_method_statistics() PRODUCT_RETURN;

   // Number of contained klasses

   // This is both fully loaded classes and classes in the process

   // of being loaded

   static int number_of_classes();

   // Monotonically increasing counter which grows as classes are

   // loaded or modifications such as hot-swapping or setting/removing

   // of breakpoints are performed

   static inline int number_of_modifications()     { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }

   // Needed by evolution and breakpoint code

   static inline void notice_modification()        { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications;      }

   // Verification

   static void verify();

 #ifdef ASSERT

   static bool is_internal_format(Symbol* class_name);

 #endif

   // Verify class is in dictionary

   static void verify_obj_klass_present(Symbol* class_name,

                                        ClassLoaderData* loader_data);

   // Initialization

   static void initialize(TRAPS);

   // Fast access to commonly used classes (preloaded)

   static Klass* check_klass(Klass* k) {

     assert(k != NULL, "preloaded klass not initialized");

     return k;

   }

   static Klass* check_klass_Pre(       Klass* k) { return check_klass(k); }

   static Klass* check_klass_Pre_JSR292(Klass* k) { return EnableInvokeDynamic ? check_klass(k) : k; }

   static Klass* check_klass_Opt(       Klass* k) { return k; }

   static Klass* check_klass_Opt_Kernel(Klass* k) { return k; } //== Opt

   static Klass* check_klass_Opt_Only_JDK15(Klass* k) {

     assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only");

     return k;

   }

   static Klass* check_klass_Opt_Only_JDK14NewRef(Klass* k) {

     assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only");

     // despite the optional loading, if you use this it must be present:

     return check_klass(k);

   }

   static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);

   static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);

   static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {

     int limit = (int)end_id + 1;

     initialize_wk_klasses_until((WKID) limit, start_id, THREAD);

   }

 public:

   #define WK_KLASS_DECLARE(name, symbol, option) \

     static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \

     static Klass** name##_addr() {                                                                       \

       return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)];           \

     }

   WK_KLASSES_DO(WK_KLASS_DECLARE);

   #undef WK_KLASS_DECLARE

   static Klass* well_known_klass(WKID id) {

     assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");

     return _well_known_klasses[id];

   }

   static Klass** well_known_klass_addr(WKID id) {

     assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");

     return &_well_known_klasses[id];

   }

   // Local definition for direct access to the private array:

   #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]

   static Klass* box_klass(BasicType t) {

     assert((uint)t < T_VOID+1, "range check");

     return check_klass(_box_klasses[t]);

   }

   static BasicType box_klass_type(Klass* k);  // inverse of box_klass

   // methods returning lazily loaded klasses

   // The corresponding method to load the class must be called before calling them.

   static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }

   static void load_abstract_ownable_synchronizer_klass(TRAPS);

 private:

   // Tells whether ClassLoader.loadClassInternal is present

   static bool has_loadClassInternal()       { return _has_loadClassInternal; }

   // Returns the class loader data to be used when looking up/updating the

   // system dictionary.

   static ClassLoaderData *class_loader_data(Handle class_loader) {

     return ClassLoaderData::class_loader_data(class_loader());

   }

 public:

   // Tells whether ClassLoader.checkPackageAccess is present

   static bool has_checkPackageAccess()      { return _has_checkPackageAccess; }

   static bool Parameter_klass_loaded()      { return WK_KLASS(reflect_Parameter_klass) != NULL; }

   static bool Class_klass_loaded()          { return WK_KLASS(Class_klass) != NULL; }

   static bool Cloneable_klass_loaded()      { return WK_KLASS(Cloneable_klass) != NULL; }

   static bool Object_klass_loaded()         { return WK_KLASS(Object_klass) != NULL; }

   static bool ClassLoader_klass_loaded()    { return WK_KLASS(ClassLoader_klass) != NULL; }

   // Returns default system loader

   static oop java_system_loader();

   // Compute the default system loader

   static void compute_java_system_loader(TRAPS);

   // Register a new class loader

   static ClassLoaderData* register_loader(Handle class_loader, TRAPS);

 private:

   // Mirrors for primitive classes (created eagerly)

   static oop check_mirror(oop m) {

     assert(m != NULL, "mirror not initialized");

     return m;

   }

 public:

   // Note:  java_lang_Class::primitive_type is the inverse of java_mirror

   // Check class loader constraints

   static bool add_loader_constraint(Symbol* name, Handle loader1,

                                     Handle loader2, TRAPS);

   static char* check_signature_loaders(Symbol* signature, Handle loader1,

                                        Handle loader2, bool is_method, TRAPS);

   // JSR 292

   // find a java.lang.invoke.MethodHandle.invoke* method for a given signature

   // (asks Java to compute it if necessary, except in a compiler thread)

   static methodHandle find_method_handle_invoker(Symbol* name,

                                                  Symbol* signature,

                                                  KlassHandle accessing_klass,

                                                  Handle *appendix_result,

                                                  Handle *method_type_result,

                                                  TRAPS);

   // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)

   // (does not ask Java, since this is a low-level intrinsic defined by the JVM)

   static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,

                                                    Symbol* signature,

                                                    TRAPS);

   // find a java.lang.invoke.MethodType object for a given signature

   // (asks Java to compute it if necessary, except in a compiler thread)

   static Handle    find_method_handle_type(Symbol* signature,

                                            KlassHandle accessing_klass,

                                            TRAPS);

   // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry

   static Handle    link_method_handle_constant(KlassHandle caller,

                                                int ref_kind, //e.g., JVM_REF_invokeVirtual

                                                KlassHandle callee,

                                                Symbol* name,

                                                Symbol* signature,

                                                TRAPS);

   // ask Java to create a dynamic call site, while linking an invokedynamic op

   static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,

                                                      Handle bootstrap_method,

                                                      Symbol* name,

                                                      Symbol* type,

                                                      Handle *appendix_result,

                                                      Handle *method_type_result,

                                                      TRAPS);

   // Utility for printing loader "name" as part of tracing constraints

   static const char* loader_name(oop loader) {

     return ((loader) == NULL ? "<bootloader>" :

             InstanceKlass::cast((loader)->klass())->name()->as_C_string() );

   }

   static const char* loader_name(ClassLoaderData* loader_data) {

     return (loader_data->class_loader() == NULL ? "<bootloader>" :

             InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() );

   }

   // Record the error when the first attempt to resolve a reference from a constant

   // pool entry to a class fails.

   static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error);

   static void delete_resolution_error(ConstantPool* pool);

   static Symbol* find_resolution_error(constantPoolHandle pool, int which);

  private:

   enum Constants {

     _loader_constraint_size = 107,                     // number of entries in constraint table

     _resolution_error_size  = 107,                     // number of entries in resolution error table

     _invoke_method_size     = 139,                     // number of entries in invoke method table

     _nof_buckets            = 1009,                    // number of buckets in hash table for placeholders

     _old_default_sdsize     = 1009,                    // backward compat for system dictionary size

     _prime_array_size       = 8,                       // array of primes for system dictionary size

     _average_depth_goal     = 3                        // goal for lookup length

   };

   // Static variables

   // hashtable sizes for system dictionary to allow growth

   // prime numbers for system dictionary size

   static int                     _sdgeneration;

   static const int               _primelist[_prime_array_size];

   // Hashtable holding loaded classes.

   static Dictionary*            _dictionary;

   // Hashtable holding placeholders for classes being loaded.

   static PlaceholderTable*       _placeholders;

   // Hashtable holding classes from the shared archive.

   static Dictionary*             _shared_dictionary;

   // Monotonically increasing counter which grows with

   // _number_of_classes as well as hot-swapping and breakpoint setting

   // and removal.

   static int                     _number_of_modifications;

   // Lock object for system class loader

   static oop                     _system_loader_lock_obj;

   // Constraints on class loaders

   static LoaderConstraintTable*  _loader_constraints;

   // Resolution errors

   static ResolutionErrorTable*   _resolution_errors;

   // Invoke methods (JSR 292)

   static SymbolPropertyTable*    _invoke_method_table;

 public:

   // for VM_CounterDecay iteration support

   friend class CounterDecay;

   static Klass* try_get_next_class();

 private:

   static void validate_protection_domain(instanceKlassHandle klass,

                                          Handle class_loader,

                                          Handle protection_domain, TRAPS);

   friend class VM_PopulateDumpSharedSpace;

   friend class TraversePlaceholdersClosure;

   static Dictionary*         dictionary() { return _dictionary; }

   static Dictionary*         shared_dictionary() { return _shared_dictionary; }

   static PlaceholderTable*   placeholders() { return _placeholders; }

   static LoaderConstraintTable* constraints() { return _loader_constraints; }

   static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }

   static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }

   // Basic loading operations

   static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);

   static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);

   static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);

   // Wait on SystemDictionary_lock; unlocks lockObject before

   // waiting; relocks lockObject with correct recursion count

   // after waiting, but before reentering SystemDictionary_lock

   // to preserve lock order semantics.

   static void double_lock_wait(Handle lockObject, TRAPS);

   static void define_instance_class(instanceKlassHandle k, TRAPS);

   static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,

                                                 Handle class_loader,

                                                 instanceKlassHandle k, TRAPS);

   static instanceKlassHandle load_shared_class(Symbol* class_name,

                                                Handle class_loader, TRAPS);

   static instanceKlassHandle load_shared_class(instanceKlassHandle ik,

                                                Handle class_loader, TRAPS);

   static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);

   static Handle compute_loader_lock_object(Handle class_loader, TRAPS);

   static void check_loader_lock_contention(Handle loader_lock, TRAPS);

   static bool is_parallelCapable(Handle class_loader);

   static bool is_parallelDefine(Handle class_loader);

   static Klass* find_shared_class(Symbol* class_name);

   // Setup link to hierarchy

   static void add_to_hierarchy(instanceKlassHandle k, TRAPS);

 private:

   // We pass in the hashtable index so we can calculate it outside of

   // the SystemDictionary_lock.

   // Basic find on loaded classes

   static Klass* find_class(int index, unsigned int hash,

                              Symbol* name, ClassLoaderData* loader_data);

   static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data);

   // Basic find on classes in the midst of being loaded

   static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);

   // Updating entry in dictionary

   // Add a completely loaded class

   static void add_klass(int index, Symbol* class_name,

                         ClassLoaderData* loader_data, KlassHandle obj);

   // Add a placeholder for a class being loaded

   static void add_placeholder(int index,

                               Symbol* class_name,

                               ClassLoaderData* loader_data);

   static void remove_placeholder(int index,

                                  Symbol* class_name,

                                  ClassLoaderData* loader_data);

   // Performs cleanups after resolve_super_or_fail. This typically needs

   // to be called on failure.

   // Won't throw, but can block.

   static void resolution_cleanups(Symbol* class_name,

                                   ClassLoaderData* loader_data,

                                   TRAPS);

   // Initialization

   static void initialize_preloaded_classes(TRAPS);

   // Class loader constraints

   static void check_constraints(int index, unsigned int hash,

                                 instanceKlassHandle k, Handle loader,

                                 bool defining, TRAPS);

   static void update_dictionary(int d_index, unsigned int d_hash,

                                 int p_index, unsigned int p_hash,

                                 instanceKlassHandle k, Handle loader,

                                 TRAPS);

   // Variables holding commonly used klasses (preloaded)

   static Klass* _well_known_klasses[];

   // Lazily loaded klasses

   static Klass* volatile _abstract_ownable_synchronizer_klass;

   // table of box klasses (int_klass, etc.)

   static Klass* _box_klasses[T_VOID+1];

   static oop  _java_system_loader;

   static bool _has_loadClassInternal;

   static bool _has_checkPackageAccess;

 };

 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP