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 /*

  * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.

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

  *

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

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

  * published by the Free Software Foundation.

  *

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

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

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

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

  * accompanied this code).

  *

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

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

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

  *

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

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

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 #ifndef SHARE_VM_CLASSFILE_DICTIONARY_HPP

 #define SHARE_VM_CLASSFILE_DICTIONARY_HPP

 #include "classfile/systemDictionary.hpp"

 #include "oops/instanceKlass.hpp"

 #include "oops/oop.inline.hpp"

 #include "utilities/hashtable.hpp"

 class DictionaryEntry;

 class PSPromotionManager;

 class ProtectionDomainCacheTable;

 class ProtectionDomainCacheEntry;

 class BoolObjectClosure;

 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 // The data structure for the system dictionary (and the shared system

 // dictionary).

 class Dictionary : public TwoOopHashtable<Klass*, mtClass> {

   friend class VMStructs;

 private:

   // current iteration index.

   static int                    _current_class_index;

   // pointer to the current hash table entry.

   static DictionaryEntry*       _current_class_entry;

   ProtectionDomainCacheTable*   _pd_cache_table;

   DictionaryEntry* get_entry(int index, unsigned int hash,

                              Symbol* name, ClassLoaderData* loader_data);

   DictionaryEntry* bucket(int i) {

     return (DictionaryEntry*)Hashtable<Klass*, mtClass>::bucket(i);

   }

   // The following method is not MT-safe and must be done under lock.

   DictionaryEntry** bucket_addr(int i) {

     return (DictionaryEntry**)Hashtable<Klass*, mtClass>::bucket_addr(i);

   }

   void add_entry(int index, DictionaryEntry* new_entry) {

     Hashtable<Klass*, mtClass>::add_entry(index, (HashtableEntry<Klass*, mtClass>*)new_entry);

   }

 public:

   Dictionary(int table_size);

   Dictionary(int table_size, HashtableBucket<mtClass>* t, int number_of_entries);

   DictionaryEntry* new_entry(unsigned int hash, Klass* klass, ClassLoaderData* loader_data);

   DictionaryEntry* new_entry();

   void free_entry(DictionaryEntry* entry);

   void add_klass(Symbol* class_name, ClassLoaderData* loader_data,KlassHandle obj);

   Klass* find_class(int index, unsigned int hash,

                       Symbol* name, ClassLoaderData* loader_data);

   Klass* find_shared_class(int index, unsigned int hash, Symbol* name);

   // Compiler support

   Klass* try_get_next_class();

   // GC support

   void oops_do(OopClosure* f);

   void always_strong_oops_do(OopClosure* blk);

   void roots_oops_do(OopClosure* strong, OopClosure* weak);

   void always_strong_classes_do(KlassClosure* closure);

   void classes_do(void f(Klass*));

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

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

   void methods_do(void f(Method*));

   void unlink(BoolObjectClosure* is_alive);

   // Classes loaded by the bootstrap loader are always strongly reachable.

   // If we're not doing class unloading, all classes are strongly reachable.

   static bool is_strongly_reachable(ClassLoaderData* loader_data, Klass* klass) {

     assert (klass != NULL, "should have non-null klass");

     return (loader_data->is_the_null_class_loader_data() || !ClassUnloading);

   }

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

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

   bool do_unloading();

   // Protection domains

   Klass* find(int index, unsigned int hash, Symbol* name,

                 ClassLoaderData* loader_data, Handle protection_domain, TRAPS);

   bool is_valid_protection_domain(int index, unsigned int hash,

                                   Symbol* name, ClassLoaderData* loader_data,

                                   Handle protection_domain);

   void add_protection_domain(int index, unsigned int hash,

                              instanceKlassHandle klass, ClassLoaderData* loader_data,

                              Handle protection_domain, TRAPS);

   // Sharing support

   void reorder_dictionary();

   ProtectionDomainCacheEntry* cache_get(oop protection_domain);

 #ifndef PRODUCT

   void print();

 #endif

   void verify();

 };

 // The following classes can be in dictionary.cpp, but we need these

 // to be in header file so that SA's vmStructs can access them.

 class ProtectionDomainCacheEntry : public HashtableEntry<oop, mtClass> {

   friend class VMStructs;

  private:

   // Flag indicating whether this protection domain entry is strongly reachable.

   // Used during iterating over the system dictionary to remember oops that need

   // to be updated.

   bool _strongly_reachable;

  public:

   oop protection_domain() { return literal(); }

   void init() {

     _strongly_reachable = false;

   }

   ProtectionDomainCacheEntry* next() {

     return (ProtectionDomainCacheEntry*)HashtableEntry<oop, mtClass>::next();

   }

   ProtectionDomainCacheEntry** next_addr() {

     return (ProtectionDomainCacheEntry**)HashtableEntry<oop, mtClass>::next_addr();

   }

   void oops_do(OopClosure* f) {

     f->do_oop(literal_addr());

   }

   void set_strongly_reachable()   { _strongly_reachable = true; }

   bool is_strongly_reachable()    { return _strongly_reachable; }

   void reset_strongly_reachable() { _strongly_reachable = false; }

   void print() PRODUCT_RETURN;

   void verify();

 };

 // The ProtectionDomainCacheTable contains all protection domain oops. The system

 // dictionary entries reference its entries instead of having references to oops

 // directly.

 // This is used to speed up system dictionary iteration: the oops in the

 // protection domain are the only ones referring the Java heap. So when there is

 // need to update these, instead of going over every entry of the system dictionary,

 // we only need to iterate over this set.

 // The amount of different protection domains used is typically magnitudes smaller

 // than the number of system dictionary entries (loaded classes).

 class ProtectionDomainCacheTable : public Hashtable<oop, mtClass> {

   friend class VMStructs;

 private:

   ProtectionDomainCacheEntry* bucket(int i) {

     return (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::bucket(i);

   }

   // The following method is not MT-safe and must be done under lock.

   ProtectionDomainCacheEntry** bucket_addr(int i) {

     return (ProtectionDomainCacheEntry**) Hashtable<oop, mtClass>::bucket_addr(i);

   }

   ProtectionDomainCacheEntry* new_entry(unsigned int hash, oop protection_domain) {

     ProtectionDomainCacheEntry* entry = (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::new_entry(hash, protection_domain);

     entry->init();

     return entry;

   }

   static unsigned int compute_hash(oop protection_domain) {

     return (unsigned int)(protection_domain->identity_hash());

   }

   int index_for(oop protection_domain) {

     return hash_to_index(compute_hash(protection_domain));

   }

   ProtectionDomainCacheEntry* add_entry(int index, unsigned int hash, oop protection_domain);

   ProtectionDomainCacheEntry* find_entry(int index, oop protection_domain);

 public:

   ProtectionDomainCacheTable(int table_size);

   ProtectionDomainCacheEntry* get(oop protection_domain);

   void free(ProtectionDomainCacheEntry* entry);

   void unlink(BoolObjectClosure* cl);

   // GC support

   void oops_do(OopClosure* f);

   void always_strong_oops_do(OopClosure* f);

   void roots_oops_do(OopClosure* strong, OopClosure* weak);

   static uint bucket_size();

   void print() PRODUCT_RETURN;

   void verify();

 };

 class ProtectionDomainEntry :public CHeapObj<mtClass> {

   friend class VMStructs;

  public:

   ProtectionDomainEntry* _next;

   ProtectionDomainCacheEntry* _pd_cache;

   ProtectionDomainEntry(ProtectionDomainCacheEntry* pd_cache, ProtectionDomainEntry* next) {

     _pd_cache = pd_cache;

     _next     = next;

   }

   ProtectionDomainEntry* next() { return _next; }

   oop protection_domain() { return _pd_cache->protection_domain(); }

 };

 // An entry in the system dictionary, this describes a class as

 // { Klass*, loader, protection_domain }.

 class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {

   friend class VMStructs;

  private:

   // Contains the set of approved protection domains that can access

   // this system dictionary entry.

   //

   // This protection domain set is a set of tuples:

   //

   // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)

   //

   // [Note that C.protection_domain(), which is stored in the java.lang.Class

   // mirror of C, is NOT the same as PD]

   //

   // If such an entry (C, ICL, PD) exists in the table, it means that

   // it is okay for a class Foo to reference C, where

   //

   //    Foo.protection_domain() == PD, and

   //    Foo's defining class loader == ICL

   //

   // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()

   // It is essentially a cache to avoid repeated Java up-calls to

   // ClassLoader.checkPackageAccess().

   //

   ProtectionDomainEntry* _pd_set;

   ClassLoaderData*       _loader_data;

  public:

   // Tells whether a protection is in the approved set.

   bool contains_protection_domain(oop protection_domain) const;

   // Adds a protection domain to the approved set.

   void add_protection_domain(Dictionary* dict, oop protection_domain);

   Klass* klass() const { return (Klass*)literal(); }

   Klass** klass_addr() { return (Klass**)literal_addr(); }

   DictionaryEntry* next() const {

     return (DictionaryEntry*)HashtableEntry<Klass*, mtClass>::next();

   }

   DictionaryEntry** next_addr() {

     return (DictionaryEntry**)HashtableEntry<Klass*, mtClass>::next_addr();

   }

   ClassLoaderData* loader_data() const { return _loader_data; }

   void set_loader_data(ClassLoaderData* loader_data) { _loader_data = loader_data; }

   ProtectionDomainEntry* pd_set() const { return _pd_set; }

   void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; }

   bool has_protection_domain() { return _pd_set != NULL; }

   // Tells whether the initiating class' protection can access the this _klass

   bool is_valid_protection_domain(Handle protection_domain) {

     if (!ProtectionDomainVerification) return true;

     if (!SystemDictionary::has_checkPackageAccess()) return true;

     return protection_domain() == NULL

          ? true

          : contains_protection_domain(protection_domain());

   }

   void set_strongly_reachable() {

     for (ProtectionDomainEntry* current = _pd_set;

                                 current != NULL;

                                 current = current->_next) {

       current->_pd_cache->set_strongly_reachable();

     }

   }

   void verify_protection_domain_set() {

     for (ProtectionDomainEntry* current = _pd_set;

                                 current != NULL;

                                 current = current->_next) {

       current->_pd_cache->protection_domain()->verify();

     }

   }

   bool equals(Symbol* class_name, ClassLoaderData* loader_data) const {

     Klass* klass = (Klass*)literal();

     return (InstanceKlass::cast(klass)->name() == class_name &&

             _loader_data == loader_data);

   }

   void print() {

     int count = 0;

     for (ProtectionDomainEntry* current = _pd_set;

                                 current != NULL;

                                 current = current->_next) {

       count++;

     }

     tty->print_cr("pd set = #%d", count);

   }

 };

 // Entry in a SymbolPropertyTable, mapping a single Symbol*

 // to a managed and an unmanaged pointer.

 class SymbolPropertyEntry : public HashtableEntry<Symbol*, mtSymbol> {

   friend class VMStructs;

  private:

   intptr_t _symbol_mode;  // secondary key

   Method*   _method;

   oop       _method_type;

  public:

   Symbol* symbol() const            { return literal(); }

   intptr_t symbol_mode() const      { return _symbol_mode; }

   void set_symbol_mode(intptr_t m)  { _symbol_mode = m; }

   Method*        method() const     { return _method; }

   void set_method(Method* p)        { _method = p; }

   oop      method_type() const      { return _method_type; }

   oop*     method_type_addr()       { return &_method_type; }

   void set_method_type(oop p)       { _method_type = p; }

   SymbolPropertyEntry* next() const {

     return (SymbolPropertyEntry*)HashtableEntry<Symbol*, mtSymbol>::next();

   }

   SymbolPropertyEntry** next_addr() {

     return (SymbolPropertyEntry**)HashtableEntry<Symbol*, mtSymbol>::next_addr();

   }

   void print_on(outputStream* st) const {

     symbol()->print_value_on(st);

     st->print("/mode="INTX_FORMAT, symbol_mode());

     st->print(" -> ");

     bool printed = false;

     if (method() != NULL) {

       method()->print_value_on(st);

       printed = true;

     }

     if (method_type() != NULL) {

       if (printed)  st->print(" and ");

       st->print(INTPTR_FORMAT, p2i((void *)method_type()));

       printed = true;

     }

     st->print_cr(printed ? "" : "(empty)");

   }

 };

 // A system-internal mapping of symbols to pointers, both managed

 // and unmanaged.  Used to record the auto-generation of each method

 // MethodHandle.invoke(S)T, for all signatures (S)T.

 class SymbolPropertyTable : public Hashtable<Symbol*, mtSymbol> {

   friend class VMStructs;

 private:

   SymbolPropertyEntry* bucket(int i) {

     return (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::bucket(i);

   }

   // The following method is not MT-safe and must be done under lock.

   SymbolPropertyEntry** bucket_addr(int i) {

     return (SymbolPropertyEntry**) Hashtable<Symbol*, mtSymbol>::bucket_addr(i);

   }

   void add_entry(int index, SymbolPropertyEntry* new_entry) {

     ShouldNotReachHere();

   }

   void set_entry(int index, SymbolPropertyEntry* new_entry) {

     ShouldNotReachHere();

   }

   SymbolPropertyEntry* new_entry(unsigned int hash, Symbol* symbol, intptr_t symbol_mode) {

     SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable<Symbol*, mtSymbol>::new_entry(hash, symbol);

     // Hashtable with Symbol* literal must increment and decrement refcount.

     symbol->increment_refcount();

     entry->set_symbol_mode(symbol_mode);

     entry->set_method(NULL);

     entry->set_method_type(NULL);

     return entry;

   }

 public:

   SymbolPropertyTable(int table_size);

   SymbolPropertyTable(int table_size, HashtableBucket<mtSymbol>* t, int number_of_entries);

   void free_entry(SymbolPropertyEntry* entry) {

     // decrement Symbol refcount here because hashtable doesn't.

     entry->literal()->decrement_refcount();

     Hashtable<Symbol*, mtSymbol>::free_entry(entry);

   }

   unsigned int compute_hash(Symbol* sym, intptr_t symbol_mode) {

     // Use the regular identity_hash.

     return Hashtable<Symbol*, mtSymbol>::compute_hash(sym) ^ symbol_mode;

   }

   int index_for(Symbol* name, intptr_t symbol_mode) {

     return hash_to_index(compute_hash(name, symbol_mode));

   }

   // need not be locked; no state change

   SymbolPropertyEntry* find_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);

   // must be done under SystemDictionary_lock

   SymbolPropertyEntry* add_entry(int index, unsigned int hash, Symbol* name, intptr_t name_mode);

   // GC support

   void oops_do(OopClosure* f);

   void methods_do(void f(Method*));

   // Sharing support

   void reorder_dictionary();

 #ifndef PRODUCT

   void print();

 #endif

   void verify();

 };

 #endif // SHARE_VM_CLASSFILE_DICTIONARY_HPP