jdk8-mips64-public/hotspot: src/share/vm/classfile/dictionary.hpp@2c6ef90f030a (annotated)

src/share/vm/classfile/dictionary.hpp@2c6ef90f030a (annotated)

src/share/vm/classfile/dictionary.hpp

Mon, 07 Jul 2014 10:12:40 +0200

author: stefank
date: Mon, 07 Jul 2014 10:12:40 +0200
changeset 6992: 2c6ef90f030a
parent 6680: 78bbf4d43a14
child 7064: c3990b8c710e
permissions: -rw-r--r--

8049421: G1 Class Unloading after completing a concurrent mark cycle
Reviewed-by: tschatzl, ehelin, brutisso, coleenp, roland, iveresov
Contributed-by: stefan.karlsson@oracle.com, mikael.gerdin@oracle.com

 /*
  * 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 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

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/classfile/dictionary.hpp@2c6ef90f030a (annotated)

src/share/vm/classfile/dictionary.hpp