/*

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 * 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

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 */

#ifndef SHARE_OOPS_OOP_HPP

#define SHARE_OOPS_OOP_HPP

#include "memory/iterator.hpp"

#include "memory/memRegion.hpp"

#include "oops/access.hpp"

#include "oops/markWord.hpp"

#include "oops/metadata.hpp"

#include "runtime/atomic.hpp"

#include "utilities/macros.hpp"

// oopDesc is the top baseclass for objects classes. The {name}Desc classes describe

// the format of Java objects so the fields can be accessed from C++.

// oopDesc is abstract.

// (see oopHierarchy for complete oop class hierarchy)

//

// no virtual functions allowed

// Forward declarations.

class OopClosure;

class ScanClosure;

class FastScanClosure;

class FilteringClosure;

class CMSIsAliveClosure;

class PSPromotionManager;

class ParCompactionManager;

class oopDesc {

  friend class VMStructs;

  friend class JVMCIVMStructs;

 private:

  volatile markWord _mark;

  union _metadata {

    Klass*      _klass;

    narrowKlass _compressed_klass;

  } _metadata;

 public:

  inline markWord  mark()          const;

  inline markWord  mark_raw()      const;

  inline markWord* mark_addr_raw() const;

  inline void set_mark(volatile markWord m);

  inline void set_mark_raw(volatile markWord m);

  static inline void set_mark_raw(HeapWord* mem, markWord m);

  inline void release_set_mark(markWord m);

  inline markWord cas_set_mark(markWord new_mark, markWord old_mark);

  inline markWord cas_set_mark_raw(markWord new_mark, markWord old_mark, atomic_memory_order order = memory_order_conservative);

  // Used only to re-initialize the mark word (e.g., of promoted

  // objects during a GC) -- requires a valid klass pointer

  inline void init_mark();

  inline void init_mark_raw();

  inline Klass* klass() const;

  inline Klass* klass_or_null() const volatile;

  inline Klass* klass_or_null_acquire() const volatile;

  static inline Klass** klass_addr(HeapWord* mem);

  static inline narrowKlass* compressed_klass_addr(HeapWord* mem);

  inline Klass** klass_addr();

  inline narrowKlass* compressed_klass_addr();

  inline void set_klass(Klass* k);

  static inline void release_set_klass(HeapWord* mem, Klass* klass);

  // For klass field compression

  inline int klass_gap() const;

  inline void set_klass_gap(int z);

  static inline void set_klass_gap(HeapWord* mem, int z);

  // For when the klass pointer is being used as a linked list "next" field.

  inline void set_klass_to_list_ptr(oop k);

  inline oop list_ptr_from_klass();

  // size of object header, aligned to platform wordSize

  static int header_size() { return sizeof(oopDesc)/HeapWordSize; }

  // Returns whether this is an instance of k or an instance of a subclass of k

  inline bool is_a(Klass* k) const;

  // Returns the actual oop size of the object

  inline int size();

  // Sometimes (for complicated concurrency-related reasons), it is useful

  // to be able to figure out the size of an object knowing its klass.

  inline int size_given_klass(Klass* klass);

  // type test operations (inlined in oop.inline.hpp)

  inline bool is_instance()            const;

  inline bool is_array()               const;

  inline bool is_objArray()            const;

  inline bool is_typeArray()           const;

  // type test operations that don't require inclusion of oop.inline.hpp.

  bool is_instance_noinline()          const;

  bool is_array_noinline()             const;

  bool is_objArray_noinline()          const;

  bool is_typeArray_noinline()         const;

 protected:

  inline oop        as_oop() const { return const_cast<oopDesc*>(this); }

 public:

  // field addresses in oop

  inline void* field_addr(int offset)     const;

  inline void* field_addr_raw(int offset) const;

  // Need this as public for garbage collection.

  template <class T> inline T* obj_field_addr_raw(int offset) const;

  template <typename T> inline size_t field_offset(T* p) const;

  // Standard compare function returns negative value if o1 < o2

  //                                   0              if o1 == o2

  //                                   positive value if o1 > o2

  inline static int  compare(oop o1, oop o2) {

    void* o1_addr = (void*)o1;

    void* o2_addr = (void*)o2;

    if (o1_addr < o2_addr) {

      return -1;

    } else if (o1_addr > o2_addr) {

      return 1;

    } else {

      return 0;

    }

  }

  // Access to fields in a instanceOop through these methods.

  template <DecoratorSet decorator>

  oop obj_field_access(int offset) const;

  oop obj_field(int offset) const;

  void obj_field_put(int offset, oop value);

  void obj_field_put_raw(int offset, oop value);

  void obj_field_put_volatile(int offset, oop value);

  Metadata* metadata_field(int offset) const;

  Metadata* metadata_field_raw(int offset) const;

  void metadata_field_put(int offset, Metadata* value);

  Metadata* metadata_field_acquire(int offset) const;

  void release_metadata_field_put(int offset, Metadata* value);

  jbyte byte_field(int offset) const;

  void byte_field_put(int offset, jbyte contents);

  jchar char_field(int offset) const;

  void char_field_put(int offset, jchar contents);

  jboolean bool_field(int offset) const;

  void bool_field_put(int offset, jboolean contents);

  jint int_field(int offset) const;

  jint int_field_raw(int offset) const;

  void int_field_put(int offset, jint contents);

  jshort short_field(int offset) const;

  void short_field_put(int offset, jshort contents);

  jlong long_field(int offset) const;

  void long_field_put(int offset, jlong contents);

  jfloat float_field(int offset) const;

  void float_field_put(int offset, jfloat contents);

  jdouble double_field(int offset) const;

  void double_field_put(int offset, jdouble contents);

  address address_field(int offset) const;

  void address_field_put(int offset, address contents);

  oop obj_field_acquire(int offset) const;

  void release_obj_field_put(int offset, oop value);

  jbyte byte_field_acquire(int offset) const;

  void release_byte_field_put(int offset, jbyte contents);

  jchar char_field_acquire(int offset) const;

  void release_char_field_put(int offset, jchar contents);

  jboolean bool_field_acquire(int offset) const;

  void release_bool_field_put(int offset, jboolean contents);

  jint int_field_acquire(int offset) const;

  void release_int_field_put(int offset, jint contents);

  jshort short_field_acquire(int offset) const;

  void release_short_field_put(int offset, jshort contents);

  jlong long_field_acquire(int offset) const;

  void release_long_field_put(int offset, jlong contents);

  jfloat float_field_acquire(int offset) const;

  void release_float_field_put(int offset, jfloat contents);

  jdouble double_field_acquire(int offset) const;

  void release_double_field_put(int offset, jdouble contents);

  address address_field_acquire(int offset) const;

  void release_address_field_put(int offset, address contents);

  // printing functions for VM debugging

  void print_on(outputStream* st) const;        // First level print

  void print_value_on(outputStream* st) const;  // Second level print.

  void print_address_on(outputStream* st) const; // Address printing

  // printing on default output stream

  void print();

  void print_value();

  void print_address();

  // return the print strings

  char* print_string();

  char* print_value_string();

  // verification operations

  static void verify_on(outputStream* st, oopDesc* oop_desc);

  static void verify(oopDesc* oopDesc);

  // locking operations

  inline bool is_locked()   const;

  inline bool is_unlocked() const;

  inline bool has_bias_pattern() const;

  inline bool has_bias_pattern_raw() const;

  // asserts and guarantees

  static bool is_oop(oop obj, bool ignore_mark_word = false);

  static bool is_oop_or_null(oop obj, bool ignore_mark_word = false);

  // garbage collection

  inline bool is_gc_marked() const;

  // Forward pointer operations for scavenge

  inline bool is_forwarded() const;

  void verify_forwardee(oop forwardee) NOT_DEBUG_RETURN;

  inline void forward_to(oop p);

  inline bool cas_forward_to(oop p, markWord compare, atomic_memory_order order = memory_order_conservative);

  // Like "forward_to", but inserts the forwarding pointer atomically.

  // Exactly one thread succeeds in inserting the forwarding pointer, and

  // this call returns "NULL" for that thread; any other thread has the

  // value of the forwarding pointer returned and does not modify "this".

  inline oop forward_to_atomic(oop p, markWord compare, atomic_memory_order order = memory_order_conservative);

  inline oop forwardee() const;

  inline oop forwardee_acquire() const;

  // Age of object during scavenge

  inline uint age() const;

  inline void incr_age();

  // mark-sweep support

  void follow_body(int begin, int end);

  template <typename OopClosureType>

  inline void oop_iterate(OopClosureType* cl);

  template <typename OopClosureType>

  inline void oop_iterate(OopClosureType* cl, MemRegion mr);

  template <typename OopClosureType>

  inline int oop_iterate_size(OopClosureType* cl);

  template <typename OopClosureType>

  inline int oop_iterate_size(OopClosureType* cl, MemRegion mr);

  template <typename OopClosureType>

  inline void oop_iterate_backwards(OopClosureType* cl);

  inline static bool is_instanceof_or_null(oop obj, Klass* klass);

  // identity hash; returns the identity hash key (computes it if necessary)

  // NOTE with the introduction of UseBiasedLocking that identity_hash() might reach a

  // safepoint if called on a biased object. Calling code must be aware of that.

  inline intptr_t identity_hash();

  intptr_t slow_identity_hash();

  // marks are forwarded to stack when object is locked

  inline bool     has_displaced_mark_raw() const;

  inline markWord displaced_mark_raw() const;

  inline void     set_displaced_mark_raw(markWord m);

  // Checks if the mark word needs to be preserved

  inline bool mark_must_be_preserved() const;

  inline bool mark_must_be_preserved(markWord m) const;

  inline bool mark_must_be_preserved_for_promotion_failure(markWord m) const;

  static bool has_klass_gap();

  // for code generation

  static int mark_offset_in_bytes()      { return offset_of(oopDesc, _mark); }

  static int klass_offset_in_bytes()     { return offset_of(oopDesc, _metadata._klass); }

  static int klass_gap_offset_in_bytes() {

    assert(has_klass_gap(), "only applicable to compressed klass pointers");

    return klass_offset_in_bytes() + sizeof(narrowKlass);

  }

  // for error reporting

  static void* load_klass_raw(oop obj);

  static void* load_oop_raw(oop obj, int offset);

};

#endif // SHARE_OOPS_OOP_HPP