       1 /*
       2  * Copyright (c) 1997, 2014, 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_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
      26 #define SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP
      27
      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"
      36
      37
      38 // The system dictionary stores all loaded classes and maps:
      39 //
      40 //   [class name,class loader] -> class   i.e.  [Symbol*,oop] -> Klass*
      41 //
      42 // Classes are loaded lazily. The default VM class loader is
      43 // represented as NULL.
      44
      45 // The underlying data structure is an open hash table with a fixed number
      46 // of buckets. During loading the loader object is locked, (for the VM loader
      47 // a private lock object is used). Class loading can thus be done concurrently,
      48 // but only by different loaders.
      49 //
      50 // During loading a placeholder (name, loader) is temporarily placed in
      51 // a side data structure, and is used to detect ClassCircularityErrors
      52 // and to perform verification during GC.  A GC can occur in the midst
      53 // of class loading, as we call out to Java, have to take locks, etc.
      54 //
      55 // When class loading is finished, a new entry is added to the system
      56 // dictionary and the place holder is removed. Note that the protection
      57 // domain field of the system dictionary has not yet been filled in when
      58 // the "real" system dictionary entry is created.
      59 //
      60 // Clients of this class who are interested in finding if a class has
      61 // been completely loaded -- not classes in the process of being loaded --
      62 // can read the SystemDictionary unlocked. This is safe because
      63 //    - entries are only deleted at safepoints
      64 //    - readers cannot come to a safepoint while actively examining
      65 //         an entry  (an entry cannot be deleted from under a reader)
      66 //    - entries must be fully formed before they are available to concurrent
      67 //         readers (we must ensure write ordering)
      68 //
      69 // Note that placeholders are deleted at any time, as they are removed
      70 // when a class is completely loaded. Therefore, readers as well as writers
      71 // of placeholders must hold the SystemDictionary_lock.
      72 //
      73
      74 class Dictionary;
      75 class PlaceholderTable;
      76 class LoaderConstraintTable;
      77 template <MEMFLAGS F> class HashtableBucket;
      78 class ResolutionErrorTable;
      79 class SymbolPropertyTable;
      80 class Ticks;
      81
      82 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
      83 // They are all "well-known", in the sense that no class loader is allowed
      84 // to provide a different definition.
      85 //
      86 // These klasses must all have names defined in vmSymbols.
      87
      88 #define WK_KLASS_ENUM_NAME(kname)    kname##_knum
      89
      90 // Each well-known class has a short klass name (like object_klass),
      91 // a vmSymbol name (like java_lang_Object), and a flag word
      92 // that makes some minor distinctions, like whether the klass
      93 // is preloaded, optional, release-specific, etc.
      94 // The order of these definitions is significant; it is the order in which
      95 // preloading is actually performed by initialize_preloaded_classes.
      96
      97 #define WK_KLASSES_DO(do_klass)                                                                                          \
      98   /* well-known classes */                                                                                               \
      99   do_klass(Object_klass,                                java_lang_Object,                          Pre                 ) \
     100   do_klass(String_klass,                                java_lang_String,                          Pre                 ) \
     101   do_klass(Class_klass,                                 java_lang_Class,                           Pre                 ) \
     102   do_klass(Cloneable_klass,                             java_lang_Cloneable,                       Pre                 ) \
     103   do_klass(ClassLoader_klass,                           java_lang_ClassLoader,                     Pre                 ) \
     104   do_klass(Serializable_klass,                          java_io_Serializable,                      Pre                 ) \
     105   do_klass(System_klass,                                java_lang_System,                          Pre                 ) \
     106   do_klass(Throwable_klass,                             java_lang_Throwable,                       Pre                 ) \
     107   do_klass(Error_klass,                                 java_lang_Error,                           Pre                 ) \
     108   do_klass(ThreadDeath_klass,                           java_lang_ThreadDeath,                     Pre                 ) \
     109   do_klass(Exception_klass,                             java_lang_Exception,                       Pre                 ) \
     110   do_klass(RuntimeException_klass,                      java_lang_RuntimeException,                Pre                 ) \
     111   do_klass(SecurityManager_klass,                       java_lang_SecurityManager,                 Pre                 ) \
     112   do_klass(ProtectionDomain_klass,                      java_security_ProtectionDomain,            Pre                 ) \
     113   do_klass(AccessControlContext_klass,                  java_security_AccessControlContext,        Pre                 ) \
     114   do_klass(SecureClassLoader_klass,                     java_security_SecureClassLoader,           Pre                 ) \
     115   do_klass(ClassNotFoundException_klass,                java_lang_ClassNotFoundException,          Pre                 ) \
     116   do_klass(NoClassDefFoundError_klass,                  java_lang_NoClassDefFoundError,            Pre                 ) \
     117   do_klass(LinkageError_klass,                          java_lang_LinkageError,                    Pre                 ) \
     118   do_klass(ClassCastException_klass,                    java_lang_ClassCastException,              Pre                 ) \
     119   do_klass(ArrayStoreException_klass,                   java_lang_ArrayStoreException,             Pre                 ) \
     120   do_klass(VirtualMachineError_klass,                   java_lang_VirtualMachineError,             Pre                 ) \
     121   do_klass(OutOfMemoryError_klass,                      java_lang_OutOfMemoryError,                Pre                 ) \
     122   do_klass(StackOverflowError_klass,                    java_lang_StackOverflowError,              Pre                 ) \
     123   do_klass(IllegalMonitorStateException_klass,          java_lang_IllegalMonitorStateException,    Pre                 ) \
     124   do_klass(Reference_klass,                             java_lang_ref_Reference,                   Pre                 ) \
     125                                                                                                                          \
     126   /* Preload ref klasses and set reference types */                                                                      \
     127   do_klass(SoftReference_klass,                         java_lang_ref_SoftReference,               Pre                 ) \
     128   do_klass(WeakReference_klass,                         java_lang_ref_WeakReference,               Pre                 ) \
     129   do_klass(FinalReference_klass,                        java_lang_ref_FinalReference,              Pre                 ) \
     130   do_klass(PhantomReference_klass,                      java_lang_ref_PhantomReference,            Pre                 ) \
     131   do_klass(Finalizer_klass,                             java_lang_ref_Finalizer,                   Pre                 ) \
     132                                                                                                                          \
     133   do_klass(Thread_klass,                                java_lang_Thread,                          Pre                 ) \
     134   do_klass(ThreadGroup_klass,                           java_lang_ThreadGroup,                     Pre                 ) \
     135   do_klass(Properties_klass,                            java_util_Properties,                      Pre                 ) \
     136   do_klass(reflect_AccessibleObject_klass,              java_lang_reflect_AccessibleObject,        Pre                 ) \
     137   do_klass(reflect_Field_klass,                         java_lang_reflect_Field,                   Pre                 ) \
     138   do_klass(reflect_Parameter_klass,                     java_lang_reflect_Parameter,               Opt                 ) \
     139   do_klass(reflect_Method_klass,                        java_lang_reflect_Method,                  Pre                 ) \
     140   do_klass(reflect_Constructor_klass,                   java_lang_reflect_Constructor,             Pre                 ) \
     141                                                                                                                          \
     142   /* NOTE: needed too early in bootstrapping process to have checks based on JDK version */                              \
     143   /* Universe::is_gte_jdk14x_version() is not set up by this point. */                                                   \
     144   /* It's okay if this turns out to be NULL in non-1.4 JDKs. */                                                          \
     145   do_klass(reflect_MagicAccessorImpl_klass,             sun_reflect_MagicAccessorImpl,             Opt                 ) \
     146   do_klass(reflect_MethodAccessorImpl_klass,            sun_reflect_MethodAccessorImpl,            Opt_Only_JDK14NewRef) \
     147   do_klass(reflect_ConstructorAccessorImpl_klass,       sun_reflect_ConstructorAccessorImpl,       Opt_Only_JDK14NewRef) \
     148   do_klass(reflect_DelegatingClassLoader_klass,         sun_reflect_DelegatingClassLoader,         Opt                 ) \
     149   do_klass(reflect_ConstantPool_klass,                  sun_reflect_ConstantPool,                  Opt_Only_JDK15      ) \
     150   do_klass(reflect_UnsafeStaticFieldAccessorImpl_klass, sun_reflect_UnsafeStaticFieldAccessorImpl, Opt_Only_JDK15      ) \
     151   do_klass(reflect_CallerSensitive_klass,               sun_reflect_CallerSensitive,               Opt                 ) \
     152                                                                                                                          \
     153   /* support for dynamic typing; it's OK if these are NULL in earlier JDKs */                                            \
     154   do_klass(DirectMethodHandle_klass,                    java_lang_invoke_DirectMethodHandle,       Opt                 ) \
     155   do_klass(MethodHandle_klass,                          java_lang_invoke_MethodHandle,             Pre_JSR292          ) \
     156   do_klass(MemberName_klass,                            java_lang_invoke_MemberName,               Pre_JSR292          ) \
     157   do_klass(MethodHandleNatives_klass,                   java_lang_invoke_MethodHandleNatives,      Pre_JSR292          ) \
     158   do_klass(LambdaForm_klass,                            java_lang_invoke_LambdaForm,               Opt                 ) \
     159   do_klass(MethodType_klass,                            java_lang_invoke_MethodType,               Pre_JSR292          ) \
     160   do_klass(BootstrapMethodError_klass,                  java_lang_BootstrapMethodError,            Pre_JSR292          ) \
     161   do_klass(CallSite_klass,                              java_lang_invoke_CallSite,                 Pre_JSR292          ) \
     162   do_klass(ConstantCallSite_klass,                      java_lang_invoke_ConstantCallSite,         Pre_JSR292          ) \
     163   do_klass(MutableCallSite_klass,                       java_lang_invoke_MutableCallSite,          Pre_JSR292          ) \
     164   do_klass(VolatileCallSite_klass,                      java_lang_invoke_VolatileCallSite,         Pre_JSR292          ) \
     165   /* Note: MethodHandle must be first, and VolatileCallSite last in group */                                             \
     166                                                                                                                          \
     167   do_klass(StringBuffer_klass,                          java_lang_StringBuffer,                    Pre                 ) \
     168   do_klass(StringBuilder_klass,                         java_lang_StringBuilder,                   Pre                 ) \
     169   do_klass(misc_Unsafe_klass,                           sun_misc_Unsafe,                           Pre                 ) \
     170                                                                                                                          \
     171   /* support for CDS */                                                                                                  \
     172   do_klass(ByteArrayInputStream_klass,                  java_io_ByteArrayInputStream,              Pre                 ) \
     173   do_klass(File_klass,                                  java_io_File,                              Pre                 ) \
     174   do_klass(URLClassLoader_klass,                        java_net_URLClassLoader,                   Pre                 ) \
     175   do_klass(URL_klass,                                   java_net_URL,                              Pre                 ) \
     176   do_klass(Jar_Manifest_klass,                          java_util_jar_Manifest,                    Pre                 ) \
     177   do_klass(sun_misc_Launcher_klass,                     sun_misc_Launcher,                         Pre                 ) \
     178   do_klass(sun_misc_Launcher_AppClassLoader_klass,      sun_misc_Launcher_AppClassLoader,          Pre                 ) \
     179   do_klass(sun_misc_Launcher_ExtClassLoader_klass,      sun_misc_Launcher_ExtClassLoader,          Pre                 ) \
     180   do_klass(CodeSource_klass,                            java_security_CodeSource,                  Pre                 ) \
     181                                                                                                                          \
     182   /* It's NULL in non-1.4 JDKs. */                                                                                       \
     183   do_klass(StackTraceElement_klass,                     java_lang_StackTraceElement,               Opt                 ) \
     184   /* Universe::is_gte_jdk14x_version() is not set up by this point. */                                                   \
     185   /* It's okay if this turns out to be NULL in non-1.4 JDKs. */                                                          \
     186   do_klass(nio_Buffer_klass,                            java_nio_Buffer,                           Opt                 ) \
     187                                                                                                                          \
     188   /* Preload boxing klasses */                                                                                           \
     189   do_klass(Boolean_klass,                               java_lang_Boolean,                         Pre                 ) \
     190   do_klass(Character_klass,                             java_lang_Character,                       Pre                 ) \
     191   do_klass(Float_klass,                                 java_lang_Float,                           Pre                 ) \
     192   do_klass(Double_klass,                                java_lang_Double,                          Pre                 ) \
     193   do_klass(Byte_klass,                                  java_lang_Byte,                            Pre                 ) \
     194   do_klass(Short_klass,                                 java_lang_Short,                           Pre                 ) \
     195   do_klass(Integer_klass,                               java_lang_Integer,                         Pre                 ) \
     196   do_klass(Long_klass,                                  java_lang_Long,                            Pre                 ) \
     197   /*end*/
     198
     199
     200 class SystemDictionary : AllStatic {
     201   friend class VMStructs;
     202   friend class SystemDictionaryHandles;
     203
     204  public:
     205   enum WKID {
     206     NO_WKID = 0,
     207
     208     #define WK_KLASS_ENUM(name, symbol, ignore_o) WK_KLASS_ENUM_NAME(name), WK_KLASS_ENUM_NAME(symbol) = WK_KLASS_ENUM_NAME(name),
     209     WK_KLASSES_DO(WK_KLASS_ENUM)
     210     #undef WK_KLASS_ENUM
     211
     212     WKID_LIMIT,
     213
     214     FIRST_WKID = NO_WKID + 1
     215   };
     216
     217   enum InitOption {
     218     Pre,                        // preloaded; error if not present
     219     Pre_JSR292,                 // preloaded if EnableInvokeDynamic
     220
     221     // Order is significant.  Options before this point require resolve_or_fail.
     222     // Options after this point will use resolve_or_null instead.
     223
     224     Opt,                        // preload tried; NULL if not present
     225     Opt_Only_JDK14NewRef,       // preload tried; use only with NewReflection
     226     Opt_Only_JDK15,             // preload tried; use only with JDK1.5+
     227     OPTION_LIMIT,
     228     CEIL_LG_OPTION_LIMIT = 4    // OPTION_LIMIT <= (1<<CEIL_LG_OPTION_LIMIT)
     229   };
     230
     231   // The system dictionary
     232   static TwoOopHashtable<Klass*, mtClass>* the_table() { return (TwoOopHashtable<Klass*, mtClass>*)dictionary(); }
     233
     234   // Returns a class with a given class name and class loader.  Loads the
     235   // class if needed. If not found a NoClassDefFoundError or a
     236   // ClassNotFoundException is thrown, depending on the value on the
     237   // throw_error flag.  For most uses the throw_error argument should be set
     238   // to true.
     239
     240   static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
     241   // Convenient call for null loader and protection domain.
     242   static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
     243 protected:
     244   // handle error translation for resolve_or_null results
     245   static Klass* handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS);
     246
     247 public:
     248
     249   // Returns a class with a given class name and class loader.
     250   // Loads the class if needed. If not found NULL is returned.
     251   static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
     252   // Version with null loader and protection domain
     253   static Klass* resolve_or_null(Symbol* class_name, TRAPS);
     254
     255   // Resolve a superclass or superinterface. Called from ClassFileParser,
     256   // parse_interfaces, resolve_instance_class_or_null, load_shared_class
     257   // "child_name" is the class whose super class or interface is being resolved.
     258   static Klass* resolve_super_or_fail(Symbol* child_name,
     259                                         Symbol* class_name,
     260                                         Handle class_loader,
     261                                         Handle protection_domain,
     262                                         bool is_superclass,
     263                                         TRAPS);
     264
     265   // Parse new stream. This won't update the system dictionary or
     266   // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
     267   static Klass* parse_stream(Symbol* class_name,
     268                                Handle class_loader,
     269                                Handle protection_domain,
     270                                ClassFileStream* st,
     271                                TRAPS) {
     272     KlassHandle nullHandle;
     273     return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
     274   }
     275   static Klass* parse_stream(Symbol* class_name,
     276                                Handle class_loader,
     277                                Handle protection_domain,
     278                                ClassFileStream* st,
     279                                KlassHandle host_klass,
     280                                GrowableArray<Handle>* cp_patches,
     281                                TRAPS);
     282
     283   // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
     284   static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader,
     285                                       Handle protection_domain,
     286                                       ClassFileStream* st, bool verify, TRAPS);
     287
     288   // Lookup an already loaded class. If not found NULL is returned.
     289   static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
     290
     291   // Lookup an already loaded instance or array class.
     292   // Do not make any queries to class loaders; consult only the cache.
     293   // If not found NULL is returned.
     294   static Klass* find_instance_or_array_klass(Symbol* class_name,
     295                                                Handle class_loader,
     296                                                Handle protection_domain,
     297                                                TRAPS);
     298
     299   // Lookup an instance or array class that has already been loaded
     300   // either into the given class loader, or else into another class
     301   // loader that is constrained (via loader constraints) to produce
     302   // a consistent class.  Do not take protection domains into account.
     303   // Do not make any queries to class loaders; consult only the cache.
     304   // Return NULL if the class is not found.
     305   //
     306   // This function is a strict superset of find_instance_or_array_klass.
     307   // This function (the unchecked version) makes a conservative prediction
     308   // of the result of the checked version, assuming successful lookup.
     309   // If both functions return non-null, they must return the same value.
     310   // Also, the unchecked version may sometimes be non-null where the
     311   // checked version is null.  This can occur in several ways:
     312   //   1. No query has yet been made to the class loader.
     313   //   2. The class loader was queried, but chose not to delegate.
     314   //   3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
     315   //   4. Loading was attempted, but there was a linkage error of some sort.
     316   // In all of these cases, the loader constraints on this type are
     317   // satisfied, and it is safe for classes in the given class loader
     318   // to manipulate strongly-typed values of the found class, subject
     319   // to local linkage and access checks.
     320   static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
     321                                                            Handle class_loader,
     322                                                            TRAPS);
     323
     324   // Iterate over all klasses in dictionary
     325   //   Just the classes from defining class loaders
     326   static void classes_do(void f(Klass*));
     327   // Added for initialize_itable_for_klass to handle exceptions
     328   static void classes_do(void f(Klass*, TRAPS), TRAPS);
     329   //   All classes, and their class loaders
     330   static void classes_do(void f(Klass*, ClassLoaderData*));
     331
     332   static void placeholders_do(void f(Symbol*));
     333
     334   // Iterate over all methods in all klasses in dictionary
     335   static void methods_do(void f(Method*));
     336
     337   // Garbage collection support
     338
     339   // This method applies "blk->do_oop" to all the pointers to "system"
     340   // classes and loaders.
     341   static void always_strong_oops_do(OopClosure* blk);
     342   static void always_strong_classes_do(KlassClosure* closure);
     343
     344   // Unload (that is, break root links to) all unmarked classes and
     345   // loaders.  Returns "true" iff something was unloaded.
     346   static bool do_unloading(BoolObjectClosure* is_alive, bool clean_alive = true);
     347
     348   // Used by DumpSharedSpaces only to remove classes that failed verification
     349   static void remove_classes_in_error_state();
     350
     351   static int calculate_systemdictionary_size(int loadedclasses);
     352
     353   // Applies "f->do_oop" to all root oops in the system dictionary.
     354   static void oops_do(OopClosure* f);
     355   static void roots_oops_do(OopClosure* strong, OopClosure* weak);
     356
     357   // System loader lock
     358   static oop system_loader_lock()           { return _system_loader_lock_obj; }
     359
     360 protected:
     361   // Extended Redefine classes support (tbi)
     362   static void preloaded_classes_do(KlassClosure* f);
     363   static void lazily_loaded_classes_do(KlassClosure* f);
     364 public:
     365   // Sharing support.
     366   static void reorder_dictionary();
     367   static void copy_buckets(char** top, char* end);
     368   static void copy_table(char** top, char* end);
     369   static void reverse();
     370   static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
     371                                     int number_of_entries);
     372   // Printing
     373   static void print(bool details = true);
     374   static void print_shared(bool details = true);
     375   static void print_class_statistics()  PRODUCT_RETURN;
     376   static void print_method_statistics() PRODUCT_RETURN;
     377
     378   // Number of contained klasses
     379   // This is both fully loaded classes and classes in the process
     380   // of being loaded
     381   static int number_of_classes();
     382
     383   // Monotonically increasing counter which grows as classes are
     384   // loaded or modifications such as hot-swapping or setting/removing
     385   // of breakpoints are performed
     386   static inline int number_of_modifications()     { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
     387   // Needed by evolution and breakpoint code
     388   static inline void notice_modification()        { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications;      }
     389
     390   // Verification
     391   static void verify();
     392
     393 #ifdef ASSERT
     394   static bool is_internal_format(Symbol* class_name);
     395 #endif
     396
     397   // Initialization
     398   static void initialize(TRAPS);
     399
     400   // Fast access to commonly used classes (preloaded)
     401   static Klass* check_klass(Klass* k) {
     402     assert(k != NULL, "preloaded klass not initialized");
     403     return k;
     404   }
     405
     406   static Klass* check_klass_Pre(       Klass* k) { return check_klass(k); }
     407   static Klass* check_klass_Pre_JSR292(Klass* k) { return EnableInvokeDynamic ? check_klass(k) : k; }
     408   static Klass* check_klass_Opt(       Klass* k) { return k; }
     409   static Klass* check_klass_Opt_Only_JDK15(Klass* k) {
     410     assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only");
     411     return k;
     412   }
     413   static Klass* check_klass_Opt_Only_JDK14NewRef(Klass* k) {
     414     assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only");
     415     // despite the optional loading, if you use this it must be present:
     416     return check_klass(k);
     417   }
     418
     419   static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
     420   static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
     421   static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
     422     int limit = (int)end_id + 1;
     423     initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
     424   }
     425
     426 public:
     427   #define WK_KLASS_DECLARE(name, symbol, option) \
     428     static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
     429     static Klass** name##_addr() {                                                                       \
     430       return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)];           \
     431     }
     432   WK_KLASSES_DO(WK_KLASS_DECLARE);
     433   #undef WK_KLASS_DECLARE
     434
     435   static Klass* well_known_klass(WKID id) {
     436     assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
     437     return _well_known_klasses[id];
     438   }
     439
     440   static Klass** well_known_klass_addr(WKID id) {
     441     assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
     442     return &_well_known_klasses[id];
     443   }
     444
     445   // Local definition for direct access to the private array:
     446   #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
     447
     448   static Klass* box_klass(BasicType t) {
     449     assert((uint)t < T_VOID+1, "range check");
     450     return check_klass(_box_klasses[t]);
     451   }
     452   static BasicType box_klass_type(Klass* k);  // inverse of box_klass
     453
     454   // methods returning lazily loaded klasses
     455   // The corresponding method to load the class must be called before calling them.
     456   static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
     457
     458   static void load_abstract_ownable_synchronizer_klass(TRAPS);
     459
     460 protected:
     461   // Tells whether ClassLoader.loadClassInternal is present
     462   static bool has_loadClassInternal()       { return _has_loadClassInternal; }
     463
     464   // Returns the class loader data to be used when looking up/updating the
     465   // system dictionary.
     466   static ClassLoaderData *class_loader_data(Handle class_loader) {
     467     return ClassLoaderData::class_loader_data(class_loader());
     468   }
     469
     470 public:
     471   // Tells whether ClassLoader.checkPackageAccess is present
     472   static bool has_checkPackageAccess()      { return _has_checkPackageAccess; }
     473
     474   static bool Parameter_klass_loaded()      { return WK_KLASS(reflect_Parameter_klass) != NULL; }
     475   static bool Class_klass_loaded()          { return WK_KLASS(Class_klass) != NULL; }
     476   static bool Cloneable_klass_loaded()      { return WK_KLASS(Cloneable_klass) != NULL; }
     477   static bool Object_klass_loaded()         { return WK_KLASS(Object_klass) != NULL; }
     478   static bool ClassLoader_klass_loaded()    { return WK_KLASS(ClassLoader_klass) != NULL; }
     479
     480   // Returns default system loader
     481   static oop java_system_loader();
     482
     483   // Compute the default system loader
     484   static void compute_java_system_loader(TRAPS);
     485
     486   // Register a new class loader
     487   static ClassLoaderData* register_loader(Handle class_loader, TRAPS);
     488 protected:
     489   // Mirrors for primitive classes (created eagerly)
     490   static oop check_mirror(oop m) {
     491     assert(m != NULL, "mirror not initialized");
     492     return m;
     493   }
     494
     495 public:
     496   // Note:  java_lang_Class::primitive_type is the inverse of java_mirror
     497
     498   // Check class loader constraints
     499   static bool add_loader_constraint(Symbol* name, Handle loader1,
     500                                     Handle loader2, TRAPS);
     501   static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
     502                                          Handle loader2, bool is_method, TRAPS);
     503
     504   // JSR 292
     505   // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
     506   // (asks Java to compute it if necessary, except in a compiler thread)
     507   static methodHandle find_method_handle_invoker(Symbol* name,
     508                                                  Symbol* signature,
     509                                                  KlassHandle accessing_klass,
     510                                                  Handle *appendix_result,
     511                                                  Handle *method_type_result,
     512                                                  TRAPS);
     513   // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
     514   // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
     515   static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
     516                                                    Symbol* signature,
     517                                                    TRAPS);
     518   // find a java.lang.invoke.MethodType object for a given signature
     519   // (asks Java to compute it if necessary, except in a compiler thread)
     520   static Handle    find_method_handle_type(Symbol* signature,
     521                                            KlassHandle accessing_klass,
     522                                            TRAPS);
     523
     524   // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
     525   static Handle    link_method_handle_constant(KlassHandle caller,
     526                                                int ref_kind, //e.g., JVM_REF_invokeVirtual
     527                                                KlassHandle callee,
     528                                                Symbol* name,
     529                                                Symbol* signature,
     530                                                TRAPS);
     531
     532   // ask Java to create a dynamic call site, while linking an invokedynamic op
     533   static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,
     534                                                      Handle bootstrap_method,
     535                                                      Symbol* name,
     536                                                      Symbol* type,
     537                                                      Handle *appendix_result,
     538                                                      Handle *method_type_result,
     539                                                      TRAPS);
     540
     541   // Utility for printing loader "name" as part of tracing constraints
     542   static const char* loader_name(oop loader) {
     543     return ((loader) == NULL ? "<bootloader>" :
     544             InstanceKlass::cast((loader)->klass())->name()->as_C_string() );
     545   }
     546   static const char* loader_name(ClassLoaderData* loader_data) {
     547     return (loader_data->class_loader() == NULL ? "<bootloader>" :
     548             InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() );
     549   }
     550
     551   // Record the error when the first attempt to resolve a reference from a constant
     552   // pool entry to a class fails.
     553   static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error);
     554   static void delete_resolution_error(ConstantPool* pool);
     555   static Symbol* find_resolution_error(constantPoolHandle pool, int which);
     556
     557  protected:
     558
     559   enum Constants {
     560     _loader_constraint_size = 107,                        // number of entries in constraint table
     561     _resolution_error_size  = 107,                        // number of entries in resolution error table
     562     _invoke_method_size     = 139,                        // number of entries in invoke method table
     563     _nof_buckets            = defaultSystemDictionarySize,// number of buckets in hash table for placeholders
     564     _old_default_sdsize     = defaultSystemDictionarySize,// backward compat for system dictionary size
     565     _prime_array_size       = 8,                          // array of primes for system dictionary size
     566     _average_depth_goal     = 3                           // goal for lookup length
     567   };
     568
     569
     570   // Static variables
     571
     572   // hashtable sizes for system dictionary to allow growth
     573   // prime numbers for system dictionary size
     574   static int                     _sdgeneration;
     575   static const int               _primelist[_prime_array_size];
     576
     577   // Hashtable holding loaded classes.
     578   static Dictionary*            _dictionary;
     579
     580   // Hashtable holding placeholders for classes being loaded.
     581   static PlaceholderTable*       _placeholders;
     582
     583   // Hashtable holding classes from the shared archive.
     584   static Dictionary*             _shared_dictionary;
     585
     586   // Monotonically increasing counter which grows with
     587   // _number_of_classes as well as hot-swapping and breakpoint setting
     588   // and removal.
     589   static int                     _number_of_modifications;
     590
     591   // Lock object for system class loader
     592   static oop                     _system_loader_lock_obj;
     593
     594   // Constraints on class loaders
     595   static LoaderConstraintTable*  _loader_constraints;
     596
     597   // Resolution errors
     598   static ResolutionErrorTable*   _resolution_errors;
     599
     600   // Invoke methods (JSR 292)
     601   static SymbolPropertyTable*    _invoke_method_table;
     602
     603 public:
     604   // for VM_CounterDecay iteration support
     605   friend class CounterDecay;
     606   static Klass* try_get_next_class();
     607
     608 protected:
     609   static void validate_protection_domain(instanceKlassHandle klass,
     610                                          Handle class_loader,
     611                                          Handle protection_domain, TRAPS);
     612
     613   friend class VM_PopulateDumpSharedSpace;
     614   friend class TraversePlaceholdersClosure;
     615   static Dictionary*         dictionary() { return _dictionary; }
     616   static Dictionary*         shared_dictionary() { return _shared_dictionary; }
     617   static PlaceholderTable*   placeholders() { return _placeholders; }
     618   static LoaderConstraintTable* constraints() { return _loader_constraints; }
     619   static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
     620   static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
     621
     622   // Basic loading operations
     623   static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
     624   static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
     625   static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
     626   // Wait on SystemDictionary_lock; unlocks lockObject before
     627   // waiting; relocks lockObject with correct recursion count
     628   // after waiting, but before reentering SystemDictionary_lock
     629   // to preserve lock order semantics.
     630   static void double_lock_wait(Handle lockObject, TRAPS);
     631   static void define_instance_class(instanceKlassHandle k, TRAPS);
     632   static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
     633                                                 Handle class_loader,
     634                                                 instanceKlassHandle k, TRAPS);
     635   static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
     636                                                Handle class_loader,
     637                                                Handle protection_domain,
     638                                                TRAPS);
     639   static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
     640   static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
     641   static void check_loader_lock_contention(Handle loader_lock, TRAPS);
     642   static bool is_parallelCapable(Handle class_loader);
     643   static bool is_parallelDefine(Handle class_loader);
     644
     645 public:
     646   static instanceKlassHandle load_shared_class(Symbol* class_name,
     647                                                Handle class_loader,
     648                                                TRAPS);
     649   static bool is_ext_class_loader(Handle class_loader);
     650
     651 protected:
     652   static Klass* find_shared_class(Symbol* class_name);
     653
     654   // Setup link to hierarchy
     655   static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
     656
     657   // event based tracing
     658   static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k,
     659                                     Handle initiating_loader);
     660
     661   // Basic find on loaded classes
     662   static Klass* find_class(unsigned int hash,
     663                              Symbol* name, ClassLoaderData* loader_data);
     664   static Klass* find_class(Symbol* class_name, ClassLoaderData* loader_data);
     665
     666   // Basic find on classes in the midst of being loaded
     667   static Symbol* find_placeholder(Symbol* name, ClassLoaderData* loader_data);
     668
     669   // Updating entry in dictionary
     670   // Add a completely loaded class
     671   static void add_klass(int index, Symbol* class_name,
     672                         ClassLoaderData* loader_data, KlassHandle obj);
     673
     674   // Add a placeholder for a class being loaded
     675   static void add_placeholder(int index,
     676                               Symbol* class_name,
     677                               ClassLoaderData* loader_data);
     678   static void remove_placeholder(int index,
     679                                  Symbol* class_name,
     680                                  ClassLoaderData* loader_data);
     681
     682   // Performs cleanups after resolve_super_or_fail. This typically needs
     683   // to be called on failure.
     684   // Won't throw, but can block.
     685   static void resolution_cleanups(Symbol* class_name,
     686                                   ClassLoaderData* loader_data,
     687                                   TRAPS);
     688
     689   // Initialization
     690   static void initialize_preloaded_classes(TRAPS);
     691
     692   // Class loader constraints
     693   static void check_constraints(unsigned int hash,
     694                                 instanceKlassHandle k, Handle loader,
     695                                 bool defining, TRAPS);
     696   static void update_dictionary(unsigned int d_hash,
     697                                 unsigned int p_hash,
     698                                 instanceKlassHandle k, Handle loader,
     699                                 TRAPS);
     700
     701   // Variables holding commonly used klasses (preloaded)
     702   static Klass* _well_known_klasses[];
     703
     704   // Lazily loaded klasses
     705   static Klass* volatile _abstract_ownable_synchronizer_klass;
     706
     707   // table of box klasses (int_klass, etc.)
     708   static Klass* _box_klasses[T_VOID+1];
     709
     710   static oop  _java_system_loader;
     711
     712   static bool _has_loadClassInternal;
     713   static bool _has_checkPackageAccess;
     714 };
     715
     716 #endif // SHARE_VM_CLASSFILE_SYSTEMDICTIONARY_HPP