       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
     232   // Returns a class with a given class name and class loader.  Loads the
     233   // class if needed. If not found a NoClassDefFoundError or a
     234   // ClassNotFoundException is thrown, depending on the value on the
     235   // throw_error flag.  For most uses the throw_error argument should be set
     236   // to true.
     237
     238   static Klass* resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS);
     239   // Convenient call for null loader and protection domain.
     240   static Klass* resolve_or_fail(Symbol* class_name, bool throw_error, TRAPS);
     241 protected:
     242   // handle error translation for resolve_or_null results
     243   static Klass* handle_resolution_exception(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, KlassHandle klass_h, TRAPS);
     244
     245 public:
     246
     247   // Returns a class with a given class name and class loader.
     248   // Loads the class if needed. If not found NULL is returned.
     249   static Klass* resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
     250   // Version with null loader and protection domain
     251   static Klass* resolve_or_null(Symbol* class_name, TRAPS);
     252
     253   // Resolve a superclass or superinterface. Called from ClassFileParser,
     254   // parse_interfaces, resolve_instance_class_or_null, load_shared_class
     255   // "child_name" is the class whose super class or interface is being resolved.
     256   static Klass* resolve_super_or_fail(Symbol* child_name,
     257                                         Symbol* class_name,
     258                                         Handle class_loader,
     259                                         Handle protection_domain,
     260                                         bool is_superclass,
     261                                         TRAPS);
     262
     263   // Parse new stream. This won't update the system dictionary or
     264   // class hierarchy, simply parse the stream. Used by JVMTI RedefineClasses.
     265   static Klass* parse_stream(Symbol* class_name,
     266                                Handle class_loader,
     267                                Handle protection_domain,
     268                                ClassFileStream* st,
     269                                TRAPS) {
     270     KlassHandle nullHandle;
     271     return parse_stream(class_name, class_loader, protection_domain, st, nullHandle, NULL, THREAD);
     272   }
     273   static Klass* parse_stream(Symbol* class_name,
     274                                Handle class_loader,
     275                                Handle protection_domain,
     276                                ClassFileStream* st,
     277                                KlassHandle host_klass,
     278                                GrowableArray<Handle>* cp_patches,
     279                                TRAPS);
     280
     281   // Resolve from stream (called by jni_DefineClass and JVM_DefineClass)
     282   static Klass* resolve_from_stream(Symbol* class_name, Handle class_loader,
     283                                       Handle protection_domain,
     284                                       ClassFileStream* st, bool verify, TRAPS);
     285
     286   // Lookup an already loaded class. If not found NULL is returned.
     287   static Klass* find(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
     288
     289   // Lookup an already loaded instance or array class.
     290   // Do not make any queries to class loaders; consult only the cache.
     291   // If not found NULL is returned.
     292   static Klass* find_instance_or_array_klass(Symbol* class_name,
     293                                                Handle class_loader,
     294                                                Handle protection_domain,
     295                                                TRAPS);
     296
     297   // Lookup an instance or array class that has already been loaded
     298   // either into the given class loader, or else into another class
     299   // loader that is constrained (via loader constraints) to produce
     300   // a consistent class.  Do not take protection domains into account.
     301   // Do not make any queries to class loaders; consult only the cache.
     302   // Return NULL if the class is not found.
     303   //
     304   // This function is a strict superset of find_instance_or_array_klass.
     305   // This function (the unchecked version) makes a conservative prediction
     306   // of the result of the checked version, assuming successful lookup.
     307   // If both functions return non-null, they must return the same value.
     308   // Also, the unchecked version may sometimes be non-null where the
     309   // checked version is null.  This can occur in several ways:
     310   //   1. No query has yet been made to the class loader.
     311   //   2. The class loader was queried, but chose not to delegate.
     312   //   3. ClassLoader.checkPackageAccess rejected a proposed protection domain.
     313   //   4. Loading was attempted, but there was a linkage error of some sort.
     314   // In all of these cases, the loader constraints on this type are
     315   // satisfied, and it is safe for classes in the given class loader
     316   // to manipulate strongly-typed values of the found class, subject
     317   // to local linkage and access checks.
     318   static Klass* find_constrained_instance_or_array_klass(Symbol* class_name,
     319                                                            Handle class_loader,
     320                                                            TRAPS);
     321
     322   // Iterate over all klasses in dictionary
     323   //   Just the classes from defining class loaders
     324   static void classes_do(void f(Klass*));
     325   // Added for initialize_itable_for_klass to handle exceptions
     326   static void classes_do(void f(Klass*, TRAPS), TRAPS);
     327   //   All classes, and their class loaders
     328   static void classes_do(void f(Klass*, ClassLoaderData*));
     329
     330   static void placeholders_do(void f(Symbol*));
     331
     332   // Iterate over all methods in all klasses in dictionary
     333   static void methods_do(void f(Method*));
     334
     335   // Garbage collection support
     336
     337   // This method applies "blk->do_oop" to all the pointers to "system"
     338   // classes and loaders.
     339   static void always_strong_oops_do(OopClosure* blk);
     340   static void always_strong_classes_do(KlassClosure* closure);
     341
     342   // Unload (that is, break root links to) all unmarked classes and
     343   // loaders.  Returns "true" iff something was unloaded.
     344   static bool do_unloading(BoolObjectClosure* is_alive, bool clean_alive = true);
     345
     346   // Used by DumpSharedSpaces only to remove classes that failed verification
     347   static void remove_classes_in_error_state();
     348
     349   static int calculate_systemdictionary_size(int loadedclasses);
     350
     351   // Applies "f->do_oop" to all root oops in the system dictionary.
     352   static void oops_do(OopClosure* f);
     353   static void roots_oops_do(OopClosure* strong, OopClosure* weak);
     354
     355   // System loader lock
     356   static oop system_loader_lock()           { return _system_loader_lock_obj; }
     357
     358 protected:
     359   // Extended Redefine classes support (tbi)
     360   static void preloaded_classes_do(KlassClosure* f);
     361   static void lazily_loaded_classes_do(KlassClosure* f);
     362 public:
     363   // Sharing support.
     364   static void reorder_dictionary();
     365   static void copy_buckets(char** top, char* end);
     366   static void copy_table(char** top, char* end);
     367   static void reverse();
     368   static void set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
     369                                     int number_of_entries);
     370   // Printing
     371   static void print(bool details = true);
     372   static void print_shared(bool details = true);
     373   static void print_class_statistics()  PRODUCT_RETURN;
     374   static void print_method_statistics() PRODUCT_RETURN;
     375
     376   // Number of contained klasses
     377   // This is both fully loaded classes and classes in the process
     378   // of being loaded
     379   static int number_of_classes();
     380
     381   // Monotonically increasing counter which grows as classes are
     382   // loaded or modifications such as hot-swapping or setting/removing
     383   // of breakpoints are performed
     384   static inline int number_of_modifications()     { assert_locked_or_safepoint(Compile_lock); return _number_of_modifications; }
     385   // Needed by evolution and breakpoint code
     386   static inline void notice_modification()        { assert_locked_or_safepoint(Compile_lock); ++_number_of_modifications;      }
     387
     388   // Verification
     389   static void verify();
     390
     391 #ifdef ASSERT
     392   static bool is_internal_format(Symbol* class_name);
     393 #endif
     394
     395   // Initialization
     396   static void initialize(TRAPS);
     397
     398   // Fast access to commonly used classes (preloaded)
     399   static Klass* check_klass(Klass* k) {
     400     assert(k != NULL, "preloaded klass not initialized");
     401     return k;
     402   }
     403
     404   static Klass* check_klass_Pre(       Klass* k) { return check_klass(k); }
     405   static Klass* check_klass_Pre_JSR292(Klass* k) { return EnableInvokeDynamic ? check_klass(k) : k; }
     406   static Klass* check_klass_Opt(       Klass* k) { return k; }
     407   static Klass* check_klass_Opt_Only_JDK15(Klass* k) {
     408     assert(JDK_Version::is_gte_jdk15x_version(), "JDK 1.5 only");
     409     return k;
     410   }
     411   static Klass* check_klass_Opt_Only_JDK14NewRef(Klass* k) {
     412     assert(JDK_Version::is_gte_jdk14x_version() && UseNewReflection, "JDK 1.4 only");
     413     // despite the optional loading, if you use this it must be present:
     414     return check_klass(k);
     415   }
     416
     417   static bool initialize_wk_klass(WKID id, int init_opt, TRAPS);
     418   static void initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS);
     419   static void initialize_wk_klasses_through(WKID end_id, WKID &start_id, TRAPS) {
     420     int limit = (int)end_id + 1;
     421     initialize_wk_klasses_until((WKID) limit, start_id, THREAD);
     422   }
     423
     424 public:
     425   #define WK_KLASS_DECLARE(name, symbol, option) \
     426     static Klass* name() { return check_klass_##option(_well_known_klasses[WK_KLASS_ENUM_NAME(name)]); } \
     427     static Klass** name##_addr() {                                                                       \
     428       return &SystemDictionary::_well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)];           \
     429     }
     430   WK_KLASSES_DO(WK_KLASS_DECLARE);
     431   #undef WK_KLASS_DECLARE
     432
     433   static Klass* well_known_klass(WKID id) {
     434     assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
     435     return _well_known_klasses[id];
     436   }
     437
     438   static Klass** well_known_klass_addr(WKID id) {
     439     assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
     440     return &_well_known_klasses[id];
     441   }
     442
     443   // Local definition for direct access to the private array:
     444   #define WK_KLASS(name) _well_known_klasses[SystemDictionary::WK_KLASS_ENUM_NAME(name)]
     445
     446   static Klass* box_klass(BasicType t) {
     447     assert((uint)t < T_VOID+1, "range check");
     448     return check_klass(_box_klasses[t]);
     449   }
     450   static BasicType box_klass_type(Klass* k);  // inverse of box_klass
     451
     452   // methods returning lazily loaded klasses
     453   // The corresponding method to load the class must be called before calling them.
     454   static Klass* abstract_ownable_synchronizer_klass() { return check_klass(_abstract_ownable_synchronizer_klass); }
     455
     456   static void load_abstract_ownable_synchronizer_klass(TRAPS);
     457
     458 protected:
     459   // Tells whether ClassLoader.loadClassInternal is present
     460   static bool has_loadClassInternal()       { return _has_loadClassInternal; }
     461
     462   // Returns the class loader data to be used when looking up/updating the
     463   // system dictionary.
     464   static ClassLoaderData *class_loader_data(Handle class_loader) {
     465     return ClassLoaderData::class_loader_data(class_loader());
     466   }
     467
     468 public:
     469   // Tells whether ClassLoader.checkPackageAccess is present
     470   static bool has_checkPackageAccess()      { return _has_checkPackageAccess; }
     471
     472   static bool Parameter_klass_loaded()      { return WK_KLASS(reflect_Parameter_klass) != NULL; }
     473   static bool Class_klass_loaded()          { return WK_KLASS(Class_klass) != NULL; }
     474   static bool Cloneable_klass_loaded()      { return WK_KLASS(Cloneable_klass) != NULL; }
     475   static bool Object_klass_loaded()         { return WK_KLASS(Object_klass) != NULL; }
     476   static bool ClassLoader_klass_loaded()    { return WK_KLASS(ClassLoader_klass) != NULL; }
     477
     478   // Returns default system loader
     479   static oop java_system_loader();
     480
     481   // Compute the default system loader
     482   static void compute_java_system_loader(TRAPS);
     483
     484   // Register a new class loader
     485   static ClassLoaderData* register_loader(Handle class_loader, TRAPS);
     486 protected:
     487   // Mirrors for primitive classes (created eagerly)
     488   static oop check_mirror(oop m) {
     489     assert(m != NULL, "mirror not initialized");
     490     return m;
     491   }
     492
     493 public:
     494   // Note:  java_lang_Class::primitive_type is the inverse of java_mirror
     495
     496   // Check class loader constraints
     497   static bool add_loader_constraint(Symbol* name, Handle loader1,
     498                                     Handle loader2, TRAPS);
     499   static Symbol* check_signature_loaders(Symbol* signature, Handle loader1,
     500                                          Handle loader2, bool is_method, TRAPS);
     501
     502   // JSR 292
     503   // find a java.lang.invoke.MethodHandle.invoke* method for a given signature
     504   // (asks Java to compute it if necessary, except in a compiler thread)
     505   static methodHandle find_method_handle_invoker(Symbol* name,
     506                                                  Symbol* signature,
     507                                                  KlassHandle accessing_klass,
     508                                                  Handle *appendix_result,
     509                                                  Handle *method_type_result,
     510                                                  TRAPS);
     511   // for a given signature, find the internal MethodHandle method (linkTo* or invokeBasic)
     512   // (does not ask Java, since this is a low-level intrinsic defined by the JVM)
     513   static methodHandle find_method_handle_intrinsic(vmIntrinsics::ID iid,
     514                                                    Symbol* signature,
     515                                                    TRAPS);
     516   // find a java.lang.invoke.MethodType object for a given signature
     517   // (asks Java to compute it if necessary, except in a compiler thread)
     518   static Handle    find_method_handle_type(Symbol* signature,
     519                                            KlassHandle accessing_klass,
     520                                            TRAPS);
     521
     522   // ask Java to compute a java.lang.invoke.MethodHandle object for a given CP entry
     523   static Handle    link_method_handle_constant(KlassHandle caller,
     524                                                int ref_kind, //e.g., JVM_REF_invokeVirtual
     525                                                KlassHandle callee,
     526                                                Symbol* name,
     527                                                Symbol* signature,
     528                                                TRAPS);
     529
     530   // ask Java to create a dynamic call site, while linking an invokedynamic op
     531   static methodHandle find_dynamic_call_site_invoker(KlassHandle caller,
     532                                                      Handle bootstrap_method,
     533                                                      Symbol* name,
     534                                                      Symbol* type,
     535                                                      Handle *appendix_result,
     536                                                      Handle *method_type_result,
     537                                                      TRAPS);
     538
     539   // Utility for printing loader "name" as part of tracing constraints
     540   static const char* loader_name(oop loader) {
     541     return ((loader) == NULL ? "<bootloader>" :
     542             InstanceKlass::cast((loader)->klass())->name()->as_C_string() );
     543   }
     544   static const char* loader_name(ClassLoaderData* loader_data) {
     545     return (loader_data->class_loader() == NULL ? "<bootloader>" :
     546             InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string() );
     547   }
     548
     549   // Record the error when the first attempt to resolve a reference from a constant
     550   // pool entry to a class fails.
     551   static void add_resolution_error(constantPoolHandle pool, int which, Symbol* error);
     552   static void delete_resolution_error(ConstantPool* pool);
     553   static Symbol* find_resolution_error(constantPoolHandle pool, int which);
     554
     555  protected:
     556
     557   enum Constants {
     558     _loader_constraint_size = 107,                     // number of entries in constraint table
     559     _resolution_error_size  = 107,                     // number of entries in resolution error table
     560     _invoke_method_size     = 139,                     // number of entries in invoke method table
     561     _nof_buckets            = 1009,                    // number of buckets in hash table for placeholders
     562     _old_default_sdsize     = 1009,                    // backward compat for system dictionary size
     563     _prime_array_size       = 8,                       // array of primes for system dictionary size
     564     _average_depth_goal     = 3                        // goal for lookup length
     565   };
     566
     567
     568   // Static variables
     569
     570   // hashtable sizes for system dictionary to allow growth
     571   // prime numbers for system dictionary size
     572   static int                     _sdgeneration;
     573   static const int               _primelist[_prime_array_size];
     574
     575   // Hashtable holding loaded classes.
     576   static Dictionary*            _dictionary;
     577
     578   // Hashtable holding placeholders for classes being loaded.
     579   static PlaceholderTable*       _placeholders;
     580
     581   // Hashtable holding classes from the shared archive.
     582   static Dictionary*             _shared_dictionary;
     583
     584   // Monotonically increasing counter which grows with
     585   // _number_of_classes as well as hot-swapping and breakpoint setting
     586   // and removal.
     587   static int                     _number_of_modifications;
     588
     589   // Lock object for system class loader
     590   static oop                     _system_loader_lock_obj;
     591
     592   // Constraints on class loaders
     593   static LoaderConstraintTable*  _loader_constraints;
     594
     595   // Resolution errors
     596   static ResolutionErrorTable*   _resolution_errors;
     597
     598   // Invoke methods (JSR 292)
     599   static SymbolPropertyTable*    _invoke_method_table;
     600
     601 public:
     602   // for VM_CounterDecay iteration support
     603   friend class CounterDecay;
     604   static Klass* try_get_next_class();
     605
     606 protected:
     607   static void validate_protection_domain(instanceKlassHandle klass,
     608                                          Handle class_loader,
     609                                          Handle protection_domain, TRAPS);
     610
     611   friend class VM_PopulateDumpSharedSpace;
     612   friend class TraversePlaceholdersClosure;
     613   static Dictionary*         dictionary() { return _dictionary; }
     614   static Dictionary*         shared_dictionary() { return _shared_dictionary; }
     615   static PlaceholderTable*   placeholders() { return _placeholders; }
     616   static LoaderConstraintTable* constraints() { return _loader_constraints; }
     617   static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
     618   static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
     619
     620   // Basic loading operations
     621   static Klass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
     622   static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
     623   static instanceKlassHandle handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
     624   // Wait on SystemDictionary_lock; unlocks lockObject before
     625   // waiting; relocks lockObject with correct recursion count
     626   // after waiting, but before reentering SystemDictionary_lock
     627   // to preserve lock order semantics.
     628   static void double_lock_wait(Handle lockObject, TRAPS);
     629   static void define_instance_class(instanceKlassHandle k, TRAPS);
     630   static instanceKlassHandle find_or_define_instance_class(Symbol* class_name,
     631                                                 Handle class_loader,
     632                                                 instanceKlassHandle k, TRAPS);
     633   static instanceKlassHandle load_shared_class(instanceKlassHandle ik,
     634                                                Handle class_loader,
     635                                                Handle protection_domain,
     636                                                TRAPS);
     637   static instanceKlassHandle load_instance_class(Symbol* class_name, Handle class_loader, TRAPS);
     638   static Handle compute_loader_lock_object(Handle class_loader, TRAPS);
     639   static void check_loader_lock_contention(Handle loader_lock, TRAPS);
     640   static bool is_parallelCapable(Handle class_loader);
     641   static bool is_parallelDefine(Handle class_loader);
     642
     643 public:
     644   static instanceKlassHandle load_shared_class(Symbol* class_name,
     645                                                Handle class_loader,
     646                                                TRAPS);
     647   static bool is_ext_class_loader(Handle class_loader);
     648
     649 protected:
     650   static Klass* find_shared_class(Symbol* class_name);
     651
     652   // Setup link to hierarchy
     653   static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
     654
     655   // event based tracing
     656   static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k,
     657                                     Handle initiating_loader);
     658   // We pass in the hashtable index so we can calculate it outside of
     659   // the SystemDictionary_lock.
     660
     661   // Basic find on loaded classes
     662   static Klass* find_class(int index, 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(int index, unsigned int hash,
     694                                 instanceKlassHandle k, Handle loader,
     695                                 bool defining, TRAPS);
     696   static void update_dictionary(int d_index, unsigned int d_hash,
     697                                 int p_index, 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