/*

 * Copyright (c) 1997, 2011, 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_INSTANCEKLASS_HPP

#define SHARE_VM_OOPS_INSTANCEKLASS_HPP

#include "oops/constMethodOop.hpp"

#include "oops/constantPoolOop.hpp"

#include "oops/fieldInfo.hpp"

#include "oops/instanceOop.hpp"

#include "oops/klassOop.hpp"

#include "oops/klassVtable.hpp"

#include "oops/objArrayOop.hpp"

#include "runtime/handles.hpp"

#include "runtime/os.hpp"

#include "utilities/accessFlags.hpp"

#include "utilities/bitMap.inline.hpp"

// An instanceKlass is the VM level representation of a Java class.

// It contains all information needed for at class at execution runtime.

//  instanceKlass layout:

//    [header                     ] klassOop

//    [klass pointer              ] klassOop

//    [C++ vtbl pointer           ] Klass

//    [subtype cache              ] Klass

//    [instance size              ] Klass

//    [java mirror                ] Klass

//    [super                      ] Klass

//    [access_flags               ] Klass

//    [name                       ] Klass

//    [first subklass             ] Klass

//    [next sibling               ] Klass

//    [array klasses              ]

//    [methods                    ]

//    [local interfaces           ]

//    [transitive interfaces      ]

//    [number of implementors     ]

//    [implementors               ] klassOop[2]

//    [fields                     ]

//    [constants                  ]

//    [class loader               ]

//    [protection domain          ]

//    [signers                    ]

//    [source file name           ]

//    [inner classes              ]

//    [static field size          ]

//    [nonstatic field size       ]

//    [static oop fields size     ]

//    [nonstatic oop maps size    ]

//    [has finalize method        ]

//    [deoptimization mark bit    ]

//    [initialization state       ]

//    [initializing thread        ]

//    [Java vtable length         ]

//    [oop map cache (stack maps) ]

//    [EMBEDDED Java vtable             ] size in words = vtable_len

//    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size

//

//    The embedded nonstatic oop-map blocks are short pairs (offset, length) indicating

//    where oops are located in instances of this klass.

// forward declaration for class -- see below for definition

class SuperTypeClosure;

class JNIid;

class jniIdMapBase;

class BreakpointInfo;

class fieldDescriptor;

class DepChange;

class nmethodBucket;

class PreviousVersionNode;

class JvmtiCachedClassFieldMap;

// This is used in iterators below.

class FieldClosure: public StackObj {

public:

  virtual void do_field(fieldDescriptor* fd) = 0;

};

#ifndef PRODUCT

// Print fields.

// If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.

class FieldPrinter: public FieldClosure {

   oop _obj;

   outputStream* _st;

 public:

   FieldPrinter(outputStream* st, oop obj = NULL) : _obj(obj), _st(st) {}

   void do_field(fieldDescriptor* fd);

};

#endif  // !PRODUCT

// ValueObjs embedded in klass. Describes where oops are located in instances of

// this klass.

class OopMapBlock VALUE_OBJ_CLASS_SPEC {

 public:

  // Byte offset of the first oop mapped by this block.

  int offset() const          { return _offset; }

  void set_offset(int offset) { _offset = offset; }

  // Number of oops in this block.

  uint count() const         { return _count; }

  void set_count(uint count) { _count = count; }

  // sizeof(OopMapBlock) in HeapWords.

  static const int size_in_words() {

    return align_size_up(int(sizeof(OopMapBlock)), HeapWordSize) >>

      LogHeapWordSize;

  }

 private:

  int  _offset;

  uint _count;

};

class instanceKlass: public Klass {

  friend class VMStructs;

 public:

  // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description

  // of the class loading & initialization procedure, and the use of the states.

  enum ClassState {

    unparsable_by_gc = 0,               // object is not yet parsable by gc. Value of _init_state at object allocation.

    allocated,                          // allocated (but not yet linked)

    loaded,                             // loaded and inserted in class hierarchy (but not linked yet)

    linked,                             // successfully linked/verified (but not initialized yet)

    being_initialized,                  // currently running class initializer

    fully_initialized,                  // initialized (successfull final state)

    initialization_error                // error happened during initialization

  };

 public:

  oop* oop_block_beg() const { return adr_array_klasses(); }

  oop* oop_block_end() const { return adr_methods_default_annotations() + 1; }

  enum {

    implementors_limit = 2              // how many implems can we track?

  };

 protected:

  //

  // The oop block.  See comment in klass.hpp before making changes.

  //

  // Array classes holding elements of this class.

  klassOop        _array_klasses;

  // Method array.

  objArrayOop     _methods;

  // Int array containing the original order of method in the class file (for

  // JVMTI).

  typeArrayOop    _method_ordering;

  // Interface (klassOops) this class declares locally to implement.

  objArrayOop     _local_interfaces;

  // Interface (klassOops) this class implements transitively.

  objArrayOop     _transitive_interfaces;

  // Instance and static variable information, 5-tuples of shorts [access, name

  // index, sig index, initval index, offset].

  typeArrayOop    _fields;

  // Constant pool for this class.

  constantPoolOop _constants;

  // Class loader used to load this class, NULL if VM loader used.

  oop             _class_loader;

  // Protection domain.

  oop             _protection_domain;

  // Host class, which grants its access privileges to this class also.

  // This is only non-null for an anonymous class (JSR 292 enabled).

  // The host class is either named, or a previously loaded anonymous class.

  klassOop        _host_klass;

  // Class signers.

  objArrayOop     _signers;

  // inner_classes attribute.

  typeArrayOop    _inner_classes;

  // Implementors of this interface (not valid if it overflows)

  klassOop        _implementors[implementors_limit];

  // Annotations for this class, or null if none.

  typeArrayOop    _class_annotations;

  // Annotation objects (byte arrays) for fields, or null if no annotations.

  // Indices correspond to entries (not indices) in fields array.

  objArrayOop     _fields_annotations;

  // Annotation objects (byte arrays) for methods, or null if no annotations.

  // Index is the idnum, which is initially the same as the methods array index.

  objArrayOop     _methods_annotations;

  // Annotation objects (byte arrays) for methods' parameters, or null if no

  // such annotations.

  // Index is the idnum, which is initially the same as the methods array index.

  objArrayOop     _methods_parameter_annotations;

  // Annotation objects (byte arrays) for methods' default values, or null if no

  // such annotations.

  // Index is the idnum, which is initially the same as the methods array index.

  objArrayOop     _methods_default_annotations;

  //

  // End of the oop block.

  //

  // Name of source file containing this klass, NULL if not specified.

  Symbol*         _source_file_name;

  // the source debug extension for this klass, NULL if not specified.

  Symbol*         _source_debug_extension;

  // Generic signature, or null if none.

  Symbol*         _generic_signature;

  // Array name derived from this class which needs unreferencing

  // if this class is unloaded.

  Symbol*         _array_name;

  // Number of heapOopSize words used by non-static fields in this klass

  // (including inherited fields but after header_size()).

  int             _nonstatic_field_size;

  int             _static_field_size;    // number words used by static fields (oop and non-oop) in this klass

  u2              _static_oop_field_count;// number of static oop fields in this klass

  u2              _java_fields_count;    // The number of declared Java fields

  int             _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks

  u2              _minor_version;        // minor version number of class file

  u2              _major_version;        // major version number of class file

  Thread*         _init_thread;          // Pointer to current thread doing initialization (to handle recusive initialization)

  int             _vtable_len;           // length of Java vtable (in words)

  int             _itable_len;           // length of Java itable (in words)

  ReferenceType   _reference_type;       // reference type

  OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)

  JNIid*          _jni_ids;              // First JNI identifier for static fields in this class

  jmethodID*      _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or NULL if none

  int*            _methods_cached_itable_indices;  // itable_index cache for JNI invoke corresponding to methods idnum, or NULL

  nmethodBucket*  _dependencies;         // list of dependent nmethods

  nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class

  BreakpointInfo* _breakpoints;          // bpt lists, managed by methodOop

  int             _nof_implementors;     // No of implementors of this interface (zero if not an interface)

  // Array of interesting part(s) of the previous version(s) of this

  // instanceKlass. See PreviousVersionWalker below.

  GrowableArray<PreviousVersionNode *>* _previous_versions;

  u2              _enclosing_method_class_index;  // Constant pool index for class of enclosing method, or 0 if none

  u2              _enclosing_method_method_index; // Constant pool index for name and type of enclosing method, or 0 if none

  // JVMTI fields can be moved to their own structure - see 6315920

  unsigned char * _cached_class_file_bytes;       // JVMTI: cached class file, before retransformable agent modified it in CFLH

  jint            _cached_class_file_len;         // JVMTI: length of above

  JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration

  volatile u2     _idnum_allocated_count;         // JNI/JVMTI: increments with the addition of methods, old ids don't change

  // Class states are defined as ClassState (see above).

  // Place the _init_state here to utilize the unused 2-byte after

  // _idnum_allocated_count.

  u1              _init_state;                    // state of class

  // Compact the following four boolean flags into 1-bit each.  These four flags

  // were defined as separate boolean fields and each was 1-byte before. Since

  // there are 2 bytes unused after the _idnum_allocated_count field, place the

  // _misc_flags field after _idnum_allocated_count to utilize the unused bits

  // and save total 4-bytes.

  enum {

    IS_MARKED_DEPENDENT  = 0x1, // used for marking during flushing and deoptimization

    REWRITTEN            = 0x2, // methods rewritten.

    HAS_NONSTATIC_FIELDS = 0x4, // for sizing with UseCompressedOops

    SHOULD_VERIFY_CLASS  = 0x8  // allow caching of preverification

  };

  u1              _misc_flags;

  // embedded Java vtable follows here

  // embedded Java itables follows here

  // embedded static fields follows here

  // embedded nonstatic oop-map blocks follows here

  friend class instanceKlassKlass;

  friend class SystemDictionary;

 public:

  bool has_nonstatic_fields() const        { return (_misc_flags & HAS_NONSTATIC_FIELDS) != 0; }

  void set_has_nonstatic_fields(bool b) {

    if (b) {

      _misc_flags |= HAS_NONSTATIC_FIELDS;

    } else {

      _misc_flags &= ~HAS_NONSTATIC_FIELDS;

    }

  }

  // field sizes

  int nonstatic_field_size() const         { return _nonstatic_field_size; }

  void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }

  int static_field_size() const            { return _static_field_size; }

  void set_static_field_size(int size)     { _static_field_size = size; }

  int static_oop_field_count() const       { return (int)_static_oop_field_count; }

  void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }

  // Java vtable

  int  vtable_length() const               { return _vtable_len; }

  void set_vtable_length(int len)          { _vtable_len = len; }

  // Java itable

  int  itable_length() const               { return _itable_len; }

  void set_itable_length(int len)          { _itable_len = len; }

  // array klasses

  klassOop array_klasses() const           { return _array_klasses; }

  void set_array_klasses(klassOop k)       { oop_store_without_check((oop*) &_array_klasses, (oop) k); }

  // methods

  objArrayOop methods() const              { return _methods; }

  void set_methods(objArrayOop a)          { oop_store_without_check((oop*) &_methods, (oop) a); }

  methodOop method_with_idnum(int idnum);

  // method ordering

  typeArrayOop method_ordering() const     { return _method_ordering; }

  void set_method_ordering(typeArrayOop m) { oop_store_without_check((oop*) &_method_ordering, (oop) m); }

  // interfaces

  objArrayOop local_interfaces() const          { return _local_interfaces; }

  void set_local_interfaces(objArrayOop a)      { oop_store_without_check((oop*) &_local_interfaces, (oop) a); }

  objArrayOop transitive_interfaces() const     { return _transitive_interfaces; }

  void set_transitive_interfaces(objArrayOop a) { oop_store_without_check((oop*) &_transitive_interfaces, (oop) a); }

 private:

  friend class fieldDescriptor;

  FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }

 public:

  int     field_offset      (int index) const { return field(index)->offset(); }

  int     field_access_flags(int index) const { return field(index)->access_flags(); }

  Symbol* field_name        (int index) const { return field(index)->name(constants()); }

  Symbol* field_signature   (int index) const { return field(index)->signature(constants()); }

  // Number of Java declared fields

  int java_fields_count() const           { return (int)_java_fields_count; }

  // Number of fields including any injected fields

  int all_fields_count() const            { return _fields->length() / sizeof(FieldInfo::field_slots); }

  typeArrayOop fields() const              { return _fields; }

  void set_fields(typeArrayOop f, u2 java_fields_count) {

    oop_store_without_check((oop*) &_fields, (oop) f);

    _java_fields_count = java_fields_count;

  }

  // inner classes

  typeArrayOop inner_classes() const       { return _inner_classes; }

  void set_inner_classes(typeArrayOop f)   { oop_store_without_check((oop*) &_inner_classes, (oop) f); }

  enum InnerClassAttributeOffset {

    // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814

    inner_class_inner_class_info_offset = 0,

    inner_class_outer_class_info_offset = 1,

    inner_class_inner_name_offset = 2,

    inner_class_access_flags_offset = 3,

    inner_class_next_offset = 4

  };

  // method override check

  bool is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);

  // package

  bool is_same_class_package(klassOop class2);

  bool is_same_class_package(oop classloader2, Symbol* classname2);

  static bool is_same_class_package(oop class_loader1, Symbol* class_name1, oop class_loader2, Symbol* class_name2);

  // find an enclosing class (defined where original code was, in jvm.cpp!)

  klassOop compute_enclosing_class(bool* inner_is_member, TRAPS) {

    instanceKlassHandle self(THREAD, this->as_klassOop());

    return compute_enclosing_class_impl(self, inner_is_member, THREAD);

  }

  static klassOop compute_enclosing_class_impl(instanceKlassHandle self,

                                               bool* inner_is_member, TRAPS);

  // tell if two classes have the same enclosing class (at package level)

  bool is_same_package_member(klassOop class2, TRAPS) {

    instanceKlassHandle self(THREAD, this->as_klassOop());

    return is_same_package_member_impl(self, class2, THREAD);

  }

  static bool is_same_package_member_impl(instanceKlassHandle self,

                                          klassOop class2, TRAPS);

  // initialization state

  bool is_loaded() const                   { return _init_state >= loaded; }

  bool is_linked() const                   { return _init_state >= linked; }

  bool is_initialized() const              { return _init_state == fully_initialized; }

  bool is_not_initialized() const          { return _init_state <  being_initialized; }

  bool is_being_initialized() const        { return _init_state == being_initialized; }

  bool is_in_error_state() const           { return _init_state == initialization_error; }

  bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }

  ClassState  init_state()                 { return (ClassState)_init_state; }

  bool is_rewritten() const                { return (_misc_flags & REWRITTEN) != 0; }

  // defineClass specified verification

  bool should_verify_class() const         { return (_misc_flags & SHOULD_VERIFY_CLASS) != 0; }

  void set_should_verify_class(bool value) {

    if (value) {

      _misc_flags |= SHOULD_VERIFY_CLASS;

    } else {

      _misc_flags &= ~SHOULD_VERIFY_CLASS;

    }

  }

  // marking

  bool is_marked_dependent() const         { return (_misc_flags & IS_MARKED_DEPENDENT) != 0; }

  void set_is_marked_dependent()           { _misc_flags |= IS_MARKED_DEPENDENT; }

  void clear_is_marked_dependent()         { _misc_flags &= ~IS_MARKED_DEPENDENT; }

  // initialization (virtuals from Klass)

  bool should_be_initialized() const;  // means that initialize should be called

  void initialize(TRAPS);

  void link_class(TRAPS);

  bool link_class_or_fail(TRAPS); // returns false on failure

  void unlink_class();

  void rewrite_class(TRAPS);

  void relocate_and_link_methods(TRAPS);

  methodOop class_initializer();

  // set the class to initialized if no static initializer is present

  void eager_initialize(Thread *thread);

  // reference type

  ReferenceType reference_type() const     { return _reference_type; }

  void set_reference_type(ReferenceType t) { _reference_type = t; }

  static ByteSize reference_type_offset() { return in_ByteSize(sizeof(klassOopDesc) + offset_of(instanceKlass, _reference_type)); }

  // find local field, returns true if found

  bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;

  // find field in direct superinterfaces, returns the interface in which the field is defined

  klassOop find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;

  // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined

  klassOop find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;

  // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined

  klassOop find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;

  // find a non-static or static field given its offset within the class.

  bool contains_field_offset(int offset) {

    return instanceOopDesc::contains_field_offset(offset, nonstatic_field_size());

  }

  bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;

  bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;

  // find a local method (returns NULL if not found)

  methodOop find_method(Symbol* name, Symbol* signature) const;

  static methodOop find_method(objArrayOop methods, Symbol* name, Symbol* signature);

  // lookup operation (returns NULL if not found)

  methodOop uncached_lookup_method(Symbol* name, Symbol* signature) const;

  // lookup a method in all the interfaces that this class implements

  // (returns NULL if not found)

  methodOop lookup_method_in_all_interfaces(Symbol* name, Symbol* signature) const;

  // constant pool

  constantPoolOop constants() const        { return _constants; }

  void set_constants(constantPoolOop c)    { oop_store_without_check((oop*) &_constants, (oop) c); }

  // class loader

  oop class_loader() const                 { return _class_loader; }

  void set_class_loader(oop l)             { oop_store((oop*) &_class_loader, l); }

  // protection domain

  oop protection_domain()                  { return _protection_domain; }

  void set_protection_domain(oop pd)       { oop_store((oop*) &_protection_domain, pd); }

  // host class

  oop host_klass() const                   { return _host_klass; }

  void set_host_klass(oop host)            { oop_store((oop*) &_host_klass, host); }

  bool is_anonymous() const                { return _host_klass != NULL; }

  // signers

  objArrayOop signers() const              { return _signers; }

  void set_signers(objArrayOop s)          { oop_store((oop*) &_signers, oop(s)); }

  // source file name

  Symbol* source_file_name() const         { return _source_file_name; }

  void set_source_file_name(Symbol* n);

  // minor and major version numbers of class file

  u2 minor_version() const                 { return _minor_version; }

  void set_minor_version(u2 minor_version) { _minor_version = minor_version; }

  u2 major_version() const                 { return _major_version; }

  void set_major_version(u2 major_version) { _major_version = major_version; }

  // source debug extension

  Symbol* source_debug_extension() const   { return _source_debug_extension; }

  void set_source_debug_extension(Symbol* n);

  // symbol unloading support (refcount already added)

  Symbol* array_name()                     { return _array_name; }

  void set_array_name(Symbol* name)        { assert(_array_name == NULL, "name already created"); _array_name = name; }

  // nonstatic oop-map blocks

  static int nonstatic_oop_map_size(unsigned int oop_map_count) {

    return oop_map_count * OopMapBlock::size_in_words();

  }

  unsigned int nonstatic_oop_map_count() const {

    return _nonstatic_oop_map_size / OopMapBlock::size_in_words();