Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 1997, 2015, 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_OOPS_KLASSVTABLE_HPP

 #define SHARE_VM_OOPS_KLASSVTABLE_HPP

 #include "memory/allocation.hpp"

 #include "oops/oopsHierarchy.hpp"

 #include "runtime/handles.hpp"

 #include "utilities/growableArray.hpp"

 // A klassVtable abstracts the variable-length vtable that is embedded in InstanceKlass

 // and ArrayKlass.  klassVtable objects are used just as convenient transient accessors to the vtable,

 // not to actually hold the vtable data.

 // Note: the klassVtable should not be accessed before the class has been verified

 // (until that point, the vtable is uninitialized).

 // Currently a klassVtable contains a direct reference to the vtable data, and is therefore

 // not preserved across GCs.

 class vtableEntry;

 class klassVtable : public ResourceObj {

   KlassHandle  _klass;            // my klass

   int          _tableOffset;      // offset of start of vtable data within klass

   int          _length;           // length of vtable (number of entries)

 #ifndef PRODUCT

   int          _verify_count;     // to make verify faster

 #endif

   // Ordering important, so greater_than (>) can be used as an merge operator.

   enum AccessType {

     acc_private         = 0,

     acc_package_private = 1,

     acc_publicprotected = 2

   };

  public:

   klassVtable(KlassHandle h_klass, void* base, int length) : _klass(h_klass) {

     _tableOffset = (address)base - (address)h_klass(); _length = length;

   }

   // accessors

   vtableEntry* table() const      { return (vtableEntry*)(address(_klass()) + _tableOffset); }

   KlassHandle klass() const       { return _klass;  }

   int length() const              { return _length; }

   inline Method* method_at(int i) const;

   inline Method* unchecked_method_at(int i) const;

   inline Method** adr_method_at(int i) const;

   // searching; all methods return -1 if not found

   int index_of(Method* m) const                         { return index_of(m, _length); }

   int index_of_miranda(Symbol* name, Symbol* signature);

   void initialize_vtable(bool checkconstraints, TRAPS);   // initialize vtable of a new klass

   // CDS/RedefineClasses support - clear vtables so they can be reinitialized

   // at dump time.  Clearing gives us an easy way to tell if the vtable has

   // already been reinitialized at dump time (see dump.cpp).  Vtables can

   // be initialized at run time by RedefineClasses so dumping the right order

   // is necessary.

   void clear_vtable();

   bool is_initialized();

   // computes vtable length (in words) and the number of miranda methods

   static void compute_vtable_size_and_num_mirandas(

       int* vtable_length, int* num_new_mirandas,

       GrowableArray<Method*>* all_mirandas, Klass* super,

       Array<Method*>* methods, AccessFlags class_flags, Handle classloader,

       Symbol* classname, Array<Klass*>* local_interfaces, TRAPS);

 #if INCLUDE_JVMTI

   // RedefineClasses() API support:

   // If any entry of this vtable points to any of old_methods,

   // replace it with the corresponding new_method.

   // trace_name_printed is set to true if the current call has

   // printed the klass name so that other routines in the adjust_*

   // group don't print the klass name.

   bool adjust_default_method(int vtable_index, Method* old_method, Method* new_method);

   void adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed);

   bool check_no_old_or_obsolete_entries();

   void dump_vtable();

 #endif // INCLUDE_JVMTI

   // Debugging code

   void print()                                              PRODUCT_RETURN;

   void verify(outputStream* st, bool force = false);

   static void print_statistics()                            PRODUCT_RETURN;

  protected:

   friend class vtableEntry;

  private:

   enum { VTABLE_TRANSITIVE_OVERRIDE_VERSION = 51 } ;

   void copy_vtable_to(vtableEntry* start);

   int  initialize_from_super(KlassHandle super);

   int  index_of(Method* m, int len) const; // same as index_of, but search only up to len

   void put_method_at(Method* m, int index);

   static bool needs_new_vtable_entry(methodHandle m, Klass* super, Handle classloader, Symbol* classname, AccessFlags access_flags, TRAPS);

   bool update_inherited_vtable(InstanceKlass* klass, methodHandle target_method, int super_vtable_len, int default_index, bool checkconstraints, TRAPS);

  InstanceKlass* find_transitive_override(InstanceKlass* initialsuper, methodHandle target_method, int vtable_index,

                                          Handle target_loader, Symbol* target_classname, Thread* THREAD);

   // support for miranda methods

   bool is_miranda_entry_at(int i);

   int fill_in_mirandas(int initialized);

   static bool is_miranda(Method* m, Array<Method*>* class_methods,

                          Array<Method*>* default_methods, Klass* super);

   static void add_new_mirandas_to_lists(

       GrowableArray<Method*>* new_mirandas,

       GrowableArray<Method*>* all_mirandas,

       Array<Method*>* current_interface_methods,

       Array<Method*>* class_methods,

       Array<Method*>* default_methods,

       Klass* super);

   static void get_mirandas(

       GrowableArray<Method*>* new_mirandas,

       GrowableArray<Method*>* all_mirandas, Klass* super,

       Array<Method*>* class_methods,

       Array<Method*>* default_methods,

       Array<Klass*>* local_interfaces);

   void verify_against(outputStream* st, klassVtable* vt, int index);

   inline InstanceKlass* ik() const;

   // When loading a class from CDS archive at run time, and no class redefintion

   // has happened, it is expected that the class's itable/vtables are

   // laid out exactly the same way as they had been during dump time.

   // Therefore, in klassVtable::initialize_[iv]table, we do not layout the

   // tables again. Instead, we only rerun the process to create/check

   // the class loader constraints. In non-product builds, we add asserts to

   // guarantee that the table's layout would be the same as at dump time.

   //

   // If JVMTI redefines any class, the read-only shared memory are remapped

   // as read-write. A shared class' vtable/itable are re-initialized and

   // might have different layout due to class redefinition of the shared class

   // or its super types.

   bool is_preinitialized_vtable();

 };

 // private helper class for klassVtable

 // description of entry points:

 //    destination is interpreted:

 //      from_compiled_code_entry_point -> c2iadapter

 //      from_interpreter_entry_point   -> interpreter entry point

 //    destination is compiled:

 //      from_compiled_code_entry_point -> nmethod entry point

 //      from_interpreter_entry_point   -> i2cadapter

 class vtableEntry VALUE_OBJ_CLASS_SPEC {

   friend class VMStructs;

  public:

   // size in words

   static int size() {

     return sizeof(vtableEntry) / sizeof(HeapWord);

   }

   static int method_offset_in_bytes() { return offset_of(vtableEntry, _method); }

   Method* method() const    { return _method; }

  private:

   Method* _method;

   void set(Method* method)  { assert(method != NULL, "use clear"); _method = method; }

   void clear()                { _method = NULL; }

   void print()                                        PRODUCT_RETURN;

   void verify(klassVtable* vt, outputStream* st);

   friend class klassVtable;

 };

 inline Method* klassVtable::method_at(int i) const {

   assert(i >= 0 && i < _length, "index out of bounds");

   assert(table()[i].method() != NULL, "should not be null");

   assert(((Metadata*)table()[i].method())->is_method(), "should be method");

   return table()[i].method();

 }

 inline Method* klassVtable::unchecked_method_at(int i) const {

   assert(i >= 0 && i < _length, "index out of bounds");

   return table()[i].method();

 }

 inline Method** klassVtable::adr_method_at(int i) const {

   // Allow one past the last entry to be referenced; useful for loop bounds.

   assert(i >= 0 && i <= _length, "index out of bounds");

   return (Method**)(address(table() + i) + vtableEntry::method_offset_in_bytes());

 }

 // --------------------------------------------------------------------------------

 class klassItable;

 class itableMethodEntry;

 class itableOffsetEntry VALUE_OBJ_CLASS_SPEC {

  private:

   Klass* _interface;

   int      _offset;

  public:

   Klass* interface_klass() const { return _interface; }

   int      offset() const          { return _offset; }

   static itableMethodEntry* method_entry(Klass* k, int offset) { return (itableMethodEntry*)(((address)k) + offset); }

   itableMethodEntry* first_method_entry(Klass* k)              { return method_entry(k, _offset); }

   void initialize(Klass* interf, int offset) { _interface = interf; _offset = offset; }

   // Static size and offset accessors

   static int size()                       { return sizeof(itableOffsetEntry) / HeapWordSize; }    // size in words

   static int interface_offset_in_bytes()  { return offset_of(itableOffsetEntry, _interface); }

   static int offset_offset_in_bytes()     { return offset_of(itableOffsetEntry, _offset); }

   friend class klassItable;

 };

 class itableMethodEntry VALUE_OBJ_CLASS_SPEC {

  private:

   Method* _method;

  public:

   Method* method() const { return _method; }

   void clear()             { _method = NULL; }

   void initialize(Method* method);

   // Static size and offset accessors

   static int size()                         { return sizeof(itableMethodEntry) / HeapWordSize; }  // size in words

   static int method_offset_in_bytes()       { return offset_of(itableMethodEntry, _method); }

   friend class klassItable;

 };

 //

 // Format of an itable

 //

 //    ---- offset table ---

 //    Klass* of interface 1             \

 //    offset to vtable from start of oop  / offset table entry

 //    ...

 //    Klass* of interface n             \

 //    offset to vtable from start of oop  / offset table entry

 //    --- vtable for interface 1 ---

 //    Method*                             \

 //    compiler entry point                / method table entry

 //    ...

 //    Method*                             \

 //    compiler entry point                / method table entry

 //    -- vtable for interface 2 ---

 //    ...

 //

 class klassItable : public ResourceObj {

  private:

   instanceKlassHandle  _klass;             // my klass

   int                  _table_offset;      // offset of start of itable data within klass (in words)

   int                  _size_offset_table; // size of offset table (in itableOffset entries)

   int                  _size_method_table; // size of methodtable (in itableMethodEntry entries)

   void initialize_itable_for_interface(int method_table_offset, KlassHandle interf_h, bool checkconstraints, TRAPS);

  public:

   klassItable(instanceKlassHandle klass);

   itableOffsetEntry* offset_entry(int i) { assert(0 <= i && i <= _size_offset_table, "index out of bounds");

                                            return &((itableOffsetEntry*)vtable_start())[i]; }

   itableMethodEntry* method_entry(int i) { assert(0 <= i && i <= _size_method_table, "index out of bounds");

                                            return &((itableMethodEntry*)method_start())[i]; }

   int size_offset_table()                { return _size_offset_table; }

   // Initialization

   void initialize_itable(bool checkconstraints, TRAPS);

   // Updates

   void initialize_with_method(Method* m);

 #if INCLUDE_JVMTI

   // RedefineClasses() API support:

   // if any entry of this itable points to any of old_methods,

   // replace it with the corresponding new_method.

   // trace_name_printed is set to true if the current call has

   // printed the klass name so that other routines in the adjust_*

   // group don't print the klass name.

   void adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed);

   bool check_no_old_or_obsolete_entries();

   void dump_itable();

 #endif // INCLUDE_JVMTI

   // Setup of itable

   static int assign_itable_indices_for_interface(Klass* klass);

   static int method_count_for_interface(Klass* klass);

   static int compute_itable_size(Array<Klass*>* transitive_interfaces);

   static void setup_itable_offset_table(instanceKlassHandle klass);

   // Resolving of method to index

   static Method* method_for_itable_index(Klass* klass, int itable_index);

   // Debugging/Statistics

   static void print_statistics() PRODUCT_RETURN;

  private:

   intptr_t* vtable_start() const { return ((intptr_t*)_klass()) + _table_offset; }

   intptr_t* method_start() const { return vtable_start() + _size_offset_table * itableOffsetEntry::size(); }

   // Helper methods

   static int  calc_itable_size(int num_interfaces, int num_methods) { return (num_interfaces * itableOffsetEntry::size()) + (num_methods * itableMethodEntry::size()); }

   // Statistics

   NOT_PRODUCT(static int  _total_classes;)   // Total no. of classes with itables

   NOT_PRODUCT(static long _total_size;)      // Total no. of bytes used for itables

   static void update_stats(int size) PRODUCT_RETURN NOT_PRODUCT({ _total_classes++; _total_size += size; })

 };

 #endif // SHARE_VM_OOPS_KLASSVTABLE_HPP