/*

 * 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

 * questions.

 *

 */

#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 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);

  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