view src/share/vm/classfile/dictionary.hpp @ 1091:6aa7255741f3

6906727: UseCompressedOops: some card-marking fixes related to object arrays Summary: Introduced a new write_ref_array(HeapWords* start, size_t count) method that does the requisite MemRegion range calculation so (some of the) clients of the erstwhile write_ref_array(MemRegion mr) do not need to worry. This removed all external uses of array_size(), which was also simplified and made private. Asserts were added to catch other possible issues. Further, less essential, fixes stemming from this investigation are deferred to CR 6904516 (to follow shortly in hs17). Reviewed-by: kvn, coleenp, jmasa
author ysr
date Thu, 03 Dec 2009 15:01:57 -0800
parents e5b0439ef4ae
children cd5dbf694d45
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/*
 * Copyright 2003-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

class DictionaryEntry;

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// The data structure for the system dictionary (and the shared system
// dictionary).

class Dictionary : public TwoOopHashtable {
  friend class VMStructs;
private:
  // current iteration index.
  static int                    _current_class_index;
  // pointer to the current hash table entry.
  static DictionaryEntry*       _current_class_entry;

  DictionaryEntry* get_entry(int index, unsigned int hash,
                             symbolHandle name, Handle loader);

  DictionaryEntry* bucket(int i) {
    return (DictionaryEntry*)Hashtable::bucket(i);
  }

  // The following method is not MT-safe and must be done under lock.
  DictionaryEntry** bucket_addr(int i) {
    return (DictionaryEntry**)Hashtable::bucket_addr(i);
  }

  void add_entry(int index, DictionaryEntry* new_entry) {
    Hashtable::add_entry(index, (HashtableEntry*)new_entry);
  }


public:
  Dictionary(int table_size);
  Dictionary(int table_size, HashtableBucket* t, int number_of_entries);

  DictionaryEntry* new_entry(unsigned int hash, klassOop klass, oop loader);

  DictionaryEntry* new_entry();

  void free_entry(DictionaryEntry* entry);

  void add_klass(symbolHandle class_name, Handle class_loader,KlassHandle obj);

  klassOop find_class(int index, unsigned int hash,
                      symbolHandle name, Handle loader);

  klassOop find_shared_class(int index, unsigned int hash, symbolHandle name);

  // Compiler support
  klassOop try_get_next_class();

  // GC support

  void oops_do(OopClosure* f);
  void always_strong_classes_do(OopClosure* blk);
  void classes_do(void f(klassOop));
  void classes_do(void f(klassOop, TRAPS), TRAPS);
  void classes_do(void f(klassOop, oop));
  void classes_do(void f(klassOop, oop, TRAPS), TRAPS);

  void methods_do(void f(methodOop));


  // 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(oop class_loader, oop klass) {
    assert (klass != NULL, "should have non-null klass");
    return (class_loader == NULL || !ClassUnloading);
  }

  // Unload (that is, break root links to) all unmarked classes and
  // loaders.  Returns "true" iff something was unloaded.
  bool do_unloading(BoolObjectClosure* is_alive);

  // Protection domains
  klassOop find(int index, unsigned int hash, symbolHandle name,
                Handle loader, Handle protection_domain, TRAPS);
  bool is_valid_protection_domain(int index, unsigned int hash,
                                  symbolHandle name, Handle class_loader,
                                  Handle protection_domain);
  void add_protection_domain(int index, unsigned int hash,
                             instanceKlassHandle klass, Handle loader,
                             Handle protection_domain, TRAPS);

  // Sharing support
  void dump(SerializeOopClosure* soc);
  void restore(SerializeOopClosure* soc);
  void reorder_dictionary();


#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.

class ProtectionDomainEntry :public CHeapObj {
  friend class VMStructs;
 public:
  ProtectionDomainEntry* _next;
  oop                    _protection_domain;

  ProtectionDomainEntry(oop protection_domain, ProtectionDomainEntry* next) {
    _protection_domain = protection_domain;
    _next              = next;
  }

  ProtectionDomainEntry* next() { return _next; }
  oop protection_domain() { return _protection_domain; }
};

// An entry in the system dictionary, this describes a class as
// { klassOop, loader, protection_domain }.

class DictionaryEntry : public HashtableEntry {
  friend class VMStructs;
 private:
  // Contains the set of approved protection domains that can access
  // this system dictionary entry.
  ProtectionDomainEntry* _pd_set;
  oop                    _loader;


 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(oop protection_domain);

  klassOop klass() const { return (klassOop)literal(); }
  klassOop* klass_addr() { return (klassOop*)literal_addr(); }

  DictionaryEntry* next() const {
    return (DictionaryEntry*)HashtableEntry::next();
  }

  DictionaryEntry** next_addr() {
    return (DictionaryEntry**)HashtableEntry::next_addr();
  }

  oop loader() const { return _loader; }
  void set_loader(oop loader) { _loader = loader; }
  oop* loader_addr() { return &_loader; }

  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 protection_domain_set_oops_do(OopClosure* f) {
    for (ProtectionDomainEntry* current = _pd_set;
                                current != NULL;
                                current = current->_next) {
      f->do_oop(&(current->_protection_domain));
    }
  }

  void verify_protection_domain_set() {
    for (ProtectionDomainEntry* current = _pd_set;
                                current != NULL;
                                current = current->_next) {
      current->_protection_domain->verify();
    }
  }

  bool equals(symbolOop class_name, oop class_loader) const {
    klassOop klass = (klassOop)literal();
    return (instanceKlass::cast(klass)->name() == class_name &&
            _loader == class_loader);
  }

  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 symbolOop
// to a managed and an unmanaged pointer.
class SymbolPropertyEntry : public HashtableEntry {
  friend class VMStructs;
 private:
  oop     _property_oop;
  address _property_data;

 public:
  symbolOop symbol() const          { return (symbolOop) literal(); }

  oop      property_oop() const     { return _property_oop; }
  void set_property_oop(oop p)      { _property_oop = p; }

  address  property_data() const    { return _property_data; }
  void set_property_data(address p) { _property_data = p; }

  SymbolPropertyEntry* next() const {
    return (SymbolPropertyEntry*)HashtableEntry::next();
  }

  SymbolPropertyEntry** next_addr() {
    return (SymbolPropertyEntry**)HashtableEntry::next_addr();
  }

  oop* symbol_addr()                { return literal_addr(); }
  oop* property_oop_addr()          { return &_property_oop; }

  void print_on(outputStream* st) const {
    symbol()->print_value_on(st);
    st->print(" -> ");
    bool printed = false;
    if (property_oop() != NULL) {
      property_oop()->print_value_on(st);
      printed = true;
    }
    if (property_data() != NULL) {
      if (printed)  st->print(" and ");
      st->print(INTPTR_FORMAT, property_data());
      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 {
  friend class VMStructs;
private:
  SymbolPropertyEntry* bucket(int i) {
    return (SymbolPropertyEntry*) Hashtable::bucket(i);
  }

  // The following method is not MT-safe and must be done under lock.
  SymbolPropertyEntry** bucket_addr(int i) {
    return (SymbolPropertyEntry**) Hashtable::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, symbolOop symbol) {
    SymbolPropertyEntry* entry = (SymbolPropertyEntry*) Hashtable::new_entry(hash, symbol);
    entry->set_property_oop(NULL);
    entry->set_property_data(NULL);
    return entry;
  }

public:
  SymbolPropertyTable(int table_size);
  SymbolPropertyTable(int table_size, HashtableBucket* t, int number_of_entries);

  void free_entry(SymbolPropertyEntry* entry) {
    Hashtable::free_entry(entry);
  }

  unsigned int compute_hash(symbolHandle sym) {
    // Use the regular identity_hash.
    return Hashtable::compute_hash(sym);
  }

  // need not be locked; no state change
  SymbolPropertyEntry* find_entry(int index, unsigned int hash, symbolHandle name);

  // must be done under SystemDictionary_lock
  SymbolPropertyEntry* add_entry(int index, unsigned int hash, symbolHandle name);

  // GC support
  void oops_do(OopClosure* f);
  void methods_do(void f(methodOop));

  // Sharing support
  void dump(SerializeOopClosure* soc);
  void restore(SerializeOopClosure* soc);
  void reorder_dictionary();

#ifndef PRODUCT
  void print();
#endif
  void verify();
};