src/share/vm/classfile/systemDictionary.hpp

Tue, 09 Oct 2012 07:41:27 +0200

author
rbackman
date
Tue, 09 Oct 2012 07:41:27 +0200
changeset 4151
6e5a59a8e4a7
parent 4133
f6b0eb4e44cf
child 4158
65d07d9ee446
permissions
-rw-r--r--

Merge

     1 /*
     2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #ifndef SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
    26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
    28 #include "classfile/classFileStream.hpp"
    29 #include "classfile/classLoader.hpp"
    30 #include "oops/objArrayOop.hpp"
    31 #include "oops/symbol.hpp"
    32 #include "runtime/java.hpp"
    33 #include "runtime/reflectionUtils.hpp"
    34 #include "utilities/hashtable.hpp"
    35 #include "utilities/hashtable.inline.hpp"
    37 // The system dictionary stores all loaded classes and maps:
    38 //
    39 //   [class name,class loader] -> class   i.e.  [Symbol*,oop] -> Klass*
    40 //
    41 // Classes are loaded lazily. The default VM class loader is
    42 // represented as NULL.
    44 // The underlying data structure is an open hash table with a fixed number
    45 // of buckets. During loading the loader object is locked, (for the VM loader
    46 // a private lock object is used). Class loading can thus be done concurrently,
    47 // but only by different loaders.
    48 //
    49 // During loading a placeholder (name, loader) is temporarily placed in
    50 // a side data structure, and is used to detect ClassCircularityErrors
    51 // and to perform verification during GC.  A GC can occur in the midst
    52 // of class loading, as we call out to Java, have to take locks, etc.
    53 //
    54 // When class loading is finished, a new entry is added to the system
    55 // dictionary and the place holder is removed. Note that the protection
    56 // domain field of the system dictionary has not yet been filled in when
    57 // the "real" system dictionary entry is created.
    58 //
    59 // Clients of this class who are interested in finding if a class has
    60 // been completely loaded -- not classes in the process of being loaded --
    61 // can read the SystemDictionary unlocked. This is safe because
    62 //    - entries are only deleted at safepoints
    63 //    - readers cannot come to a safepoint while actively examining
    64 //         an entry  (an entry cannot be deleted from under a reader)
    65 //    - entries must be fully formed before they are available to concurrent
    66 //         readers (we must ensure write ordering)
    67 //
    68 // Note that placeholders are deleted at any time, as they are removed
    69 // when a class is completely loaded. Therefore, readers as well as writers
    70 // of placeholders must hold the SystemDictionary_lock.
    71 //
    73 class Dictionary;
    74 class PlaceholderTable;
    75 class LoaderConstraintTable;
    76 template <MEMFLAGS F> class HashtableBucket;
    77 class ResolutionErrorTable;
    78 class SymbolPropertyTable;
    80 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
    81 // They are all "well-known", in the sense that no class loader is allowed
    82 // to provide a different definition.
    83 //
    84 // These klasses must all have names defined in vmSymbols.
    86 #define WK_KLASS_ENUM_NAME(kname)    kname##_knum
    88 // Each well-known class has a short klass name (like object_klass),
    89 // a vmSymbol name (like java_lang_Object), and a flag word
    90 // that makes some minor distinctions, like whether the klass
    91 // is preloaded, optional, release-specific, etc.
    92 // The order of these definitions is significant; it is the order in which
    93 // preloading is actually performed by initialize_preloaded_classes.
    95 #define WK_KLASSES_DO(template)                                               \
    96   /* well-known classes */                                                    \
    97   template(Object_klass,                 java_lang_Object,               Pre) \
    98   template(String_klass,                 java_lang_String,               Pre) \
    99   template(Class_klass,                  java_lang_Class,                Pre) \
   100   template(Cloneable_klass,              java_lang_Cloneable,            Pre) \
   101   template(ClassLoader_klass,            java_lang_ClassLoader,          Pre) \
   102   template(Serializable_klass,           java_io_Serializable,           Pre) \
   103   template(System_klass,                 java_lang_System,               Pre) \
   104   template(Throwable_klass,              java_lang_Throwable,            Pre) \
   105   template(Error_klass,                  java_lang_Error,                Pre) \
   106   template(ThreadDeath_klass,            java_lang_ThreadDeath,          Pre) \
   107   template(Exception_klass,              java_lang_Exception,            Pre) \
   108   template(RuntimeException_klass,       java_lang_RuntimeException,     Pre) \
   109   template(ProtectionDomain_klass,       java_security_ProtectionDomain, Pre) \
   110   template(AccessControlContext_klass,   java_security_AccessControlContext, Pre) \
   111   template(ClassNotFoundException_klass, java_lang_ClassNotFoundException, Pre) \
   112   template(NoClassDefFoundError_klass,   java_lang_NoClassDefFoundError, Pre) \
   113   template(LinkageError_klass,           java_lang_LinkageError,         Pre) \
   114   template(ClassCastException_klass,     java_lang_ClassCastException,   Pre) \
   115   template(ArrayStoreException_klass,    java_lang_ArrayStoreException,  Pre) \
   116   template(VirtualMachineError_klass,    java_lang_VirtualMachineError,  Pre) \
   117   template(OutOfMemoryError_klass,       java_lang_OutOfMemoryError,     Pre) \
   118   template(StackOverflowError_klass,     java_lang_StackOverflowError,   Pre) \
   119   template(IllegalMonitorStateException_klass, java_lang_IllegalMonitorStateException, Pre) \
   120   template(Reference_klass,              java_lang_ref_Reference,        Pre) \
   121                                                                               \
   122   /* Preload ref klasses and set reference types */                           \
   123   template(SoftReference_klass,          java_lang_ref_SoftReference,    Pre) \
   124   template(WeakReference_klass,          java_lang_ref_WeakReference,    Pre) \
   125   template(FinalReference_klass,         java_lang_ref_FinalReference,   Pre) \
   126   template(PhantomReference_klass,       java_lang_ref_PhantomReference, Pre) \
   127   template(Finalizer_klass,              java_lang_ref_Finalizer,        Pre) \
   128                                                                               \
   129   template(Thread_klass,                 java_lang_Thread,               Pre) \
   130   template(ThreadGroup_klass,            java_lang_ThreadGroup,          Pre) \
   131   template(Properties_klass,             java_util_Properties,           Pre) \
   132   template(reflect_AccessibleObject_klass, java_lang_reflect_AccessibleObject, Pre) \
   133   template(reflect_Field_klass,          java_lang_reflect_Field,        Pre) \
   134   template(reflect_Method_klass,         java_lang_reflect_Method,       Pre) \
   135   template(reflect_Constructor_klass,    java_lang_reflect_Constructor,  Pre) \
   136                                                                               \
   137   /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */                              \
   138   /* Universe::is_gte_jdk14x_version() is not set up by this point. */                                                   \
   139   /* It's okay if this turns out to be NULL in non-1.4 JDKs. */                                                          \
   140   template(reflect_MagicAccessorImpl_klass,             sun_reflect_MagicAccessorImpl,             Opt)                  \
   141   template(reflect_MethodAccessorImpl_klass,            sun_reflect_MethodAccessorImpl,            Opt_Only_JDK14NewRef) \
   142   template(reflect_ConstructorAccessorImpl_klass,       sun_reflect_ConstructorAccessorImpl,       Opt_Only_JDK14NewRef) \
   143   template(reflect_DelegatingClassLoader_klass,         sun_reflect_DelegatingClassLoader,         Opt)                  \
   144   template(reflect_ConstantPool_klass,                  sun_reflect_ConstantPool,                  Opt_Only_JDK15)       \
   145   template(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15)       \
   146                                                                               \
   147   /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */ \
   148   template(MethodHandle_klass,             java_lang_invoke_MethodHandle,             Pre_JSR292) \
   149   template(MemberName_klass,               java_lang_invoke_MemberName,               Pre_JSR292) \
   150   template(MethodHandleNatives_klass,      java_lang_invoke_MethodHandleNatives,      Pre_JSR292) \
   151   template(LambdaForm_klass,               java_lang_invoke_LambdaForm,               Opt)        \
   152   template(MethodType_klass,               java_lang_invoke_MethodType,               Pre_JSR292) \
   153   template(BootstrapMethodError_klass,     java_lang_BootstrapMethodError,            Pre_JSR292) \
   154   template(CallSite_klass,                 java_lang_invoke_CallSite,                 Pre_JSR292) \
   155   template(ConstantCallSite_klass,         java_lang_invoke_ConstantCallSite,         Pre_JSR292) \
   156   template(MutableCallSite_klass,          java_lang_invoke_MutableCallSite,          Pre_JSR292) \
   157   template(VolatileCallSite_klass,         java_lang_invoke_VolatileCallSite,         Pre_JSR292) \
   158   /* Note: MethodHandle must be first, and VolatileCallSite last in group */  \
   159                                                                               \
   160   template(StringBuffer_klass,           java_lang_StringBuffer,         Pre) \
   161   template(StringBuilder_klass,          java_lang_StringBuilder,        Pre) \
   162                                                                               \
   163   /* It's NULL in non-1.4 JDKs. */                                            \
   164   template(StackTraceElement_klass,      java_lang_StackTraceElement,    Opt) \
   165   /* Universe::is_gte_jdk14x_version() is not set up by this point. */        \
   166   /* It's okay if this turns out to be NULL in non-1.4 JDKs. */               \
   167   template(nio_Buffer_klass,             java_nio_Buffer,                Opt) \
   168                                                                               \
   169   template(DownloadManager_klass,        sun_jkernel_DownloadManager, Opt_Kernel) \
   170                                                                               \
   171   template(PostVMInitHook_klass,         sun_misc_PostVMInitHook, Opt)        \
   172                                                                               \
   173   /* Preload boxing klasses */                                                \
   174   template(Boolean_klass,                java_lang_Boolean,              Pre) \
   175   template(Character_klass,              java_lang_Character,            Pre) \
   176   template(Float_klass,                  java_lang_Float,                Pre) \
   177   template(Double_klass,                 java_lang_Double,               Pre) \
   178   template(Byte_klass,                   java_lang_Byte,                 Pre) \
   179   template(Short_klass,                  java_lang_Short,                Pre) \
   180   template(Integer_klass,                java_lang_Integer,              Pre) \
   181   template(Long_klass,                   java_lang_Long,                 Pre) \
   182   /*end*/
   185 class SystemDictionary : AllStatic {
   186   friend class VMStructs;
   187   friend class SystemDictionaryHandles;
   189  public:
   190   enum WKID {
   191     NO_WKID = 0,
   193     #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
   194     WK_KLASSES_DO(WK_KLASS_ENUM)
   195     #undef WK_KLASS_ENUM
   197     WKID_LIMIT,
   199     FIRST_WKID = NO_WKID + 1
   200   };
   202   enum InitOption {
   203     Pre,                        // preloaded; error if not present
   204     Pre_JSR292,                 // preloaded if EnableInvokeDynamic
   206     // Order is significant.  Options before this point require resolve_or_fail.
   207     // Options after this point will use resolve_or_null instead.
   209     Opt,                        // preload tried; NULL if not present
   210     Opt_Only_JDK14NewRef,       // preload tried; use only with NewReflection
   211     Opt_Only_JDK15,             // preload tried; use only with JDK1.5+
   212     Opt_Kernel,                 // preload tried only #ifdef KERNEL
   213     OPTION_LIMIT,
   214     CEIL_LG_OPTION_LIMIT = 4    // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
   215   };
   218   // Returns a class with a given class name and class loader.  Loads the
   219   // class if needed. If not found a NoClassDefFoundError or a
   220   // ClassNotFoundException is thrown, depending on the value on the
   221   // throw_error flag.  For most uses the throw_error argument should be set
   222   // to true.
   224   static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
   225   // Convenient call for null loader and protection domain.
   226   static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
   227 private:
   228   // handle error translation for resolve_or_null results
   229   static Klass* handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS);
   231 public:
   233   // Returns a class with a given class name and class loader.
   234   // Loads the class if needed. If not found NULL is returned.
   235   static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
   236   // Version with null loader and protection domain
   237   static Klass* resolve_or_null(Symbol* class_name, TRAPS);
   239   // Resolve a superclass or superinterface. Called from ClassFileParser,
   240   // parse_interfaces, resolve_instance_class_or_null, load_shared_class
   241   // "child_name" is the class whose super class or interface is being resolved.
   242   static Klass* resolve_super_or_fail(Symbol* child_name,
   243                                         Symbol* class_name,
   244                                         Handle class_loader,
   245                                         Handle protection_domain,
   246                                         bool is_superclass,
   247                                         TRAPS);
   249   // Parse new stream. This won't update the system dictionary or
   250   // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
   251   static Klass* parse_stream(Symbol* class_name,
   252                                Handle class_loader,
   253                                Handle protection_domain,
   254                                ClassFileStream* st,
   255                                TRAPS) {
   256     KlassHandle nullHandle;
   257     return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
   258   }
   259   static Klass* parse_stream(Symbol* class_name,
   260                                Handle class_loader,
   261                                Handle protection_domain,
   262                                ClassFileStream* st,
   263                                KlassHandle host_klass,
   264                                GrowableArray<Handle>* cp_patches,
   265                                TRAPS);
   267   // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
   268   static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader,
   269                                       Handle protection_domain,
   270                                       ClassFileStream* st, bool verify, TRAPS);
   272   // Lookup an already loaded class. If not found NULL is returned.
   273   static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
   275   // Lookup an already loaded instance or array class.
   276   // Do not make any queries to class loaders; consult only the cache.
   277   // If not found NULL is returned.
   278   static Klass* find_instance_or_array_klass(Symbol* class_name,
   279                                                Handle class_loader,
   280                                                Handle protection_domain,
   281                                                TRAPS);
   283   // If the given name is known to vmSymbols, return the well-know klass:
   284   static Klass* find_well_known_klass(Symbol* class_name);
   286   // Lookup an instance or array class that has already been loaded
   287   // either into the given class loader, or else into another class
   288   // loader that is constrained (via loader constraints) to produce
   289   // a consistent class.  Do not take protection domains into account.
   290   // Do not make any queries to class loaders; consult only the cache.
   291   // Return NULL if the class is not found.
   292   //
   293   // This function is a strict superset of find_instance_or_array_klass.
   294   // This function (the unchecked version) makes a conservative prediction
   295   // of the result of the checked version, assuming successful lookup.
   296   // If both functions return non-null, they must return the same value.
   297   // Also, the unchecked version may sometimes be non-null where the
   298   // checked version is null.  This can occur in several ways:
   299   //   1. No query has yet been made to the class loader.
   300   //   2. The class loader was queried, but chose not to delegate.
   301   //   3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
   302   //   4. Loading was attempted, but there was a linkage error of some sort.
   303   // In all of these cases, the loader constraints on this type are
   304   // satisfied, and it is safe for classes in the given class loader
   305   // to manipulate strongly-typed values of the found class, subject
   306   // to local linkage and access checks.
   307   static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
   308                                                            Handle class_loader,
   309                                                            TRAPS);
   311   // Iterate over all klasses in dictionary
   312   //   Just the classes from defining class loaders
   313   static void classes_do(void f(Klass*));
   314   // Added for initialize_itable_for_klass to handle exceptions
   315   static void classes_do(void f(Klass*, TRAPS), TRAPS);
   316   //   All classes, and their class loaders
   317   static void classes_do(void f(Klass*, ClassLoaderData*));
   318   //   All classes, and their class loaders
   319   //   (added for helpers that use HandleMarks and ResourceMarks)
   320   static void classes_do(void f(Klass*, ClassLoaderData*, TRAPS), TRAPS);
   321   // All entries in the placeholder table and their class loaders
   322   static void placeholders_do(void f(Symbol*));
   324   // Iterate over all methods in all klasses in dictionary
   325   static void methods_do(void f(Method*));
   327   // Garbage collection support
   329   // This method applies "blk->do_oop" to all the pointers to "system"
   330   // classes and loaders.
   331   static void always_strong_oops_do(OopClosure* blk);
   332   static void always_strong_classes_do(KlassClosure* closure);
   334   // Unload (that is, break root links to) all unmarked classes and
   335   // loaders.  Returns "true" iff something was unloaded.
   336   static bool do_unloading(BoolObjectClosure* is_alive);
   338   static int calculate_systemdictionary_size(int loadedclasses);
   340   // Applies "f->do_oop" to all root oops in the system dictionary.
   341   static void oops_do(OopClosure* f);
   343   // System loader lock
   344   static oop system_loader_lock()           { return _system_loader_lock_obj; }
   346 private:
   347   // Extended Redefine classes support (tbi)
   348   static void preloaded_classes_do(KlassClosure* f);
   349   static void lazily_loaded_classes_do(KlassClosure* f);
   350 public:
   351   // Sharing support.
   352   static void reorder_dictionary();
   353   static void copy_buckets(char** top, char* end);
   354   static void copy_table(char** top, char* end);
   355   static void reverse();
   356   static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
   357                                     int number_of_entries);
   358   // Printing
   359   static void print()                   PRODUCT_RETURN;
   360   static void print_class_statistics()  PRODUCT_RETURN;
   361   static void print_method_statistics() PRODUCT_RETURN;
   363   // Number of contained klasses
   364   // This is both fully loaded classes and classes in the process
   365   // of being loaded
   366   static int number_of_classes();
   368   // Monotonically increasing counter which grows as classes are
   369   // loaded or modifications such as hot-swapping or setting/removing
   370   // of breakpoints are performed
   371   static inline int number_of_modifications()     { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
   372   // Needed by evolution and breakpoint code
   373   static inline void notice_modification()        { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications;      }
   375   // Verification
   376   static void verify();
   378 #ifdef ASSERT
   379   static bool is_internal_format(Symbol* class_name);
   380 #endif
   382   // Verify class is in dictionary
   383   static void verify_obj_klass_present(Symbol* class_name,
   384                                        ClassLoaderData* loader_data);
   386   // Initialization
   387   static void initialize(TRAPS);
   389   // Fast access to commonly used classes (preloaded)
   390   static Klass* check_klass(Klass* k) {
   391     assert(k != NULL, "preloaded klass not initialized");
   392     return k;
   393   }
   395   static Klass* check_klass_Pre(Klass* k) { return check_klass(k); }
   396   static Klass* check_klass_Pre_JSR292(Klass* k) { return EnableInvokeDynamic ? check_klass(k) : k; }
   397   static Klass* check_klass_Opt(Klass* k) { return k; }
   398   static Klass* check_klass_Opt_Kernel(Klass* k) { return k; } //== Opt
   399   static Klass* check_klass_Opt_Only_JDK15(Klass* k) {
   400     assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only");
   401     return k;
   402   }
   403   static Klass* check_klass_Opt_Only_JDK14NewRef(Klass* k) {
   404     assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only");
   405     // despite the optional loading, if you use this it must be present:
   406     return check_klass(k);
   407   }
   409   static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
   410   static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
   411   static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
   412     int limit = (int)end_id + 1;
   413     initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
   414   }
   416 public:
   417   #define WK_KLASS_DECLARE(name, symbol, option) \
   418     static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
   419     static Klass** name##_addr() {                                                                       \
   420       return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)];           \
   421     }
   422   WK_KLASSES_DO(WK_KLASS_DECLARE);
   423   #undef WK_KLASS_DECLARE
   425   static Klass* well_known_klass(WKID id) {
   426     assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
   427     return _well_known_klasses[id];
   428   }
   430   static Klass** well_known_klass_addr(WKID id) {
   431     assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
   432     return &_well_known_klasses[id];
   433   }
   435   // Local definition for direct access to the private array:
   436   #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
   438   static Klass* box_klass(BasicType t) {
   439     assert((uint)t < T_VOID+1, "range check");
   440     return check_klass(_box_klasses[t]);
   441   }
   442   static BasicType box_klass_type(Klass* k);  // inverse of box_klass
   444   // methods returning lazily loaded klasses
   445   // The corresponding method to load the class must be called before calling them.
   446   static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
   448   static void load_abstract_ownable_synchronizer_klass(TRAPS);
   450 private:
   451   // Tells whether ClassLoader.loadClassInternal is present
   452   static bool has_loadClassInternal()       { return _has_loadClassInternal; }
   454   // Returns the class loader data to be used when looking up/updating the
   455   // system dictionary.
   456   static ClassLoaderData *class_loader_data(Handle class_loader) {
   457     return ClassLoaderData::class_loader_data(class_loader());
   458   }
   460 public:
   461   // Tells whether ClassLoader.checkPackageAccess is present
   462   static bool has_checkPackageAccess()      { return _has_checkPackageAccess; }
   464   static bool Class_klass_loaded()          { return WK_KLASS(Class_klass) != NULL; }
   465   static bool Cloneable_klass_loaded()      { return WK_KLASS(Cloneable_klass) != NULL; }
   466   static bool Object_klass_loaded()         { return WK_KLASS(Object_klass) != NULL; }
   467   static bool ClassLoader_klass_loaded()    { return WK_KLASS(ClassLoader_klass) != NULL; }
   469   // Returns default system loader
   470   static oop java_system_loader();
   472   // Compute the default system loader
   473   static void compute_java_system_loader(TRAPS);
   475   // Register a new class loader
   476   static ClassLoaderData* register_loader(Handle class_loader);
   477 private:
   478   // Mirrors for primitive classes (created eagerly)
   479   static oop check_mirror(oop m) {
   480     assert(m != NULL, "mirror not initialized");
   481     return m;
   482   }
   484 public:
   485   // Note:  java_lang_Class::primitive_type is the inverse of java_mirror
   487   // Check class loader constraints
   488   static bool add_loader_constraint(Symbol* name, Handle loader1,
   489                                     Handle loader2, TRAPS);
   490   static char* check_signature_loaders(Symbol* signature, Handle loader1,
   491                                        Handle loader2, bool is_method, TRAPS);
   493   // JSR 292
   494   // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
   495   // (asks Java to compute it if necessary, except in a compiler thread)
   496   static methodHandle find_method_handle_invoker(Symbol* name,
   497                                                  Symbol* signature,
   498                                                  KlassHandle accessing_klass,
   499                                                  Handle *appendix_result,
   500                                                  Handle *method_type_result,
   501                                                  TRAPS);
   502   // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
   503   // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
   504   static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
   505                                                    Symbol* signature,
   506                                                    TRAPS);
   507   // find a java.lang.invoke.MethodType object for a given signature
   508   // (asks Java to compute it if necessary, except in a compiler thread)
   509   static Handle    find_method_handle_type(Symbol* signature,
   510                                            KlassHandle accessing_klass,
   511                                            TRAPS);
   513   // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
   514   static Handle    link_method_handle_constant(KlassHandle caller,
   515                                                int ref_kind, //e.g., JVM_REF_invokeVirtual
   516                                                KlassHandle callee,
   517                                                Symbol* name,
   518                                                Symbol* signature,
   519                                                TRAPS);
   521   // ask Java to create a dynamic call site, while linking an invokedynamic op
   522   static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,
   523                                                      Handle bootstrap_method,
   524                                                      Symbol* name,
   525                                                      Symbol* type,
   526                                                      Handle *appendix_result,
   527                                                      Handle *method_type_result,
   528                                                      TRAPS);
   530   // Utility for printing loader "name" as part of tracing constraints
   531   static const char* loader_name(oop loader) {
   532     return ((loader) == NULL ? "<bootloader>" :
   533             InstanceKlass::cast((loader)->klass())->name()->as_C_string() );
   534   }
   535   static const char* loader_name(ClassLoaderData* loader_data) {
   536     return (loader_data->is_the_null_class_loader_data() ? "<bootloader>" :
   537             InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() );
   538   }
   540   // Record the error when the first attempt to resolve a reference from a constant
   541   // pool entry to a class fails.
   542   static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error);
   543   static void delete_resolution_error(ConstantPool* pool);
   544   static Symbol* find_resolution_error(constantPoolHandle pool, int which);
   546  private:
   548   enum Constants {
   549     _loader_constraint_size = 107,                     // number of entries in constraint table
   550     _resolution_error_size  = 107,                     // number of entries in resolution error table
   551     _invoke_method_size     = 139,                     // number of entries in invoke method table
   552     _nof_buckets            = 1009,                    // number of buckets in hash table for placeholders
   553     _old_default_sdsize     = 1009,                    // backward compat for system dictionary size
   554     _prime_array_size       = 8,                       // array of primes for system dictionary size
   555     _average_depth_goal     = 3                        // goal for lookup length
   556   };
   559   // Static variables
   561   // hashtable sizes for system dictionary to allow growth
   562   // prime numbers for system dictionary size
   563   static int                     _sdgeneration;
   564   static const int               _primelist[_prime_array_size];
   566   // Hashtable holding loaded classes.
   567   static Dictionary*            _dictionary;
   569   // Hashtable holding placeholders for classes being loaded.
   570   static PlaceholderTable*       _placeholders;
   572   // Hashtable holding classes from the shared archive.
   573   static Dictionary*             _shared_dictionary;
   575   // Monotonically increasing counter which grows with
   576   // _number_of_classes as well as hot-swapping and breakpoint setting
   577   // and removal.
   578   static int                     _number_of_modifications;
   580   // Lock object for system class loader
   581   static oop                     _system_loader_lock_obj;
   583   // Constraints on class loaders
   584   static LoaderConstraintTable*  _loader_constraints;
   586   // Resolution errors
   587   static ResolutionErrorTable*   _resolution_errors;
   589   // Invoke methods (JSR 292)
   590   static SymbolPropertyTable*    _invoke_method_table;
   592 public:
   593   // for VM_CounterDecay iteration support
   594   friend class CounterDecay;
   595   static Klass* try_get_next_class();
   597 private:
   598   static void validate_protection_domain(instanceKlassHandle klass,
   599                                          Handle class_loader,
   600                                          Handle protection_domain, TRAPS);
   602   friend class VM_PopulateDumpSharedSpace;
   603   friend class TraversePlaceholdersClosure;
   604   static Dictionary*         dictionary() { return _dictionary; }
   605   static Dictionary*         shared_dictionary() { return _shared_dictionary; }
   606   static PlaceholderTable*   placeholders() { return _placeholders; }
   607   static LoaderConstraintTable* constraints() { return _loader_constraints; }
   608   static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
   609   static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
   611   // Basic loading operations
   612   static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
   613   static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
   614   static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
   615   // Wait on SystemDictionary_lock; unlocks lockObject before
   616   // waiting; relocks lockObject with correct recursion count
   617   // after waiting, but before reentering SystemDictionary_lock
   618   // to preserve lock order semantics.
   619   static void double_lock_wait(Handle lockObject, TRAPS);
   620   static void define_instance_class(instanceKlassHandle k, TRAPS);
   621   static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
   622                                                 Handle class_loader,
   623                                                 instanceKlassHandle k, TRAPS);
   624   static instanceKlassHandle load_shared_class(Symbol* class_name,
   625                                                Handle class_loader, TRAPS);
   626   static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
   627                                                Handle class_loader, TRAPS);
   628   static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
   629   static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
   630   static void check_loader_lock_contention(Handle loader_lock, TRAPS);
   631   static bool is_parallelCapable(Handle class_loader);
   632   static bool is_parallelDefine(Handle class_loader);
   634   static Klass* find_shared_class(Symbol* class_name);
   636   // Setup link to hierarchy
   637   static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
   639 private:
   640   // We pass in the hashtable index so we can calculate it outside of
   641   // the SystemDictionary_lock.
   643   // Basic find on loaded classes
   644   static Klass* find_class(int index, unsigned int hash,
   645                              Symbol* name, ClassLoaderData* loader_data);
   646   static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
   648   // Basic find on classes in the midst of being loaded
   649   static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
   651   // Updating entry in dictionary
   652   // Add a completely loaded class
   653   static void add_klass(int index, Symbol* class_name,
   654                         ClassLoaderData* loader_data, KlassHandle obj);
   656   // Add a placeholder for a class being loaded
   657   static void add_placeholder(int index,
   658                               Symbol* class_name,
   659                               ClassLoaderData* loader_data);
   660   static void remove_placeholder(int index,
   661                                  Symbol* class_name,
   662                                  ClassLoaderData* loader_data);
   664   // Performs cleanups after resolve_super_or_fail. This typically needs
   665   // to be called on failure.
   666   // Won't throw, but can block.
   667   static void resolution_cleanups(Symbol* class_name,
   668                                   ClassLoaderData* loader_data,
   669                                   TRAPS);
   671   // Initialization
   672   static void initialize_preloaded_classes(TRAPS);
   674   // Class loader constraints
   675   static void check_constraints(int index, unsigned int hash,
   676                                 instanceKlassHandle k, Handle loader,
   677                                 bool defining, TRAPS);
   678   static void update_dictionary(int d_index, unsigned int d_hash,
   679                                 int p_index, unsigned int p_hash,
   680                                 instanceKlassHandle k, Handle loader,
   681                                 TRAPS);
   683   // Variables holding commonly used klasses (preloaded)
   684   static Klass* _well_known_klasses[];
   686   // Lazily loaded klasses
   687   static Klass* volatile _abstract_ownable_synchronizer_klass;
   689   // table of box klasses (int_klass, etc.)
   690   static Klass* _box_klasses[T_VOID+1];
   692   static oop  _java_system_loader;
   694   static bool _has_loadClassInternal;
   695   static bool _has_checkPackageAccess;
   696 };
   698 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP

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