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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 *

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 * 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).

 *

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 * 2 along with this work; if not, write to the Free Software Foundation,

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#ifndef SHARE_VM_OOPS_OOP_HPP

#define SHARE_VM_OOPS_OOP_HPP

#include "gc/shared/specialized_oop_closures.hpp"

#include "memory/iterator.hpp"

#include "memory/memRegion.hpp"

#include "oops/access.hpp"

#include "oops/metadata.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

extern bool always_do_update_barrier;

// Forward declarations.

class OopClosure;

class ScanClosure;

class FastScanClosure;

class FilteringClosure;

class BarrierSet;

class CMSIsAliveClosure;

class PSPromotionManager;

class ParCompactionManager;

class oopDesc {

  friend class VMStructs;

  friend class JVMCIVMStructs;

 private:

  volatile markOop _mark;

  union _metadata {

    Klass*      _klass;

    narrowKlass _compressed_klass;

  } _metadata;

 public:

  markOop  mark()      const { return _mark; }

  markOop* mark_addr() const { return (markOop*) &_mark; }

  void set_mark(volatile markOop m) { _mark = m; }

  inline void release_set_mark(markOop m);

  inline markOop cas_set_mark(markOop new_mark, markOop old_mark);

  // 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 Klass* klass() const;

  inline Klass* klass_or_null() const volatile;

  inline Klass* klass_or_null_acquire() const volatile;

  inline Klass** klass_addr();

  inline narrowKlass* compressed_klass_addr();

  inline void set_klass(Klass* k);

  inline void release_set_klass(Klass* k);

  // For klass field compression

  inline int klass_gap() const;

  inline void set_klass_gap(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;

  inline static bool is_null(oop obj)       { return obj == NULL; }

  inline static bool is_null(narrowOop obj) { return obj == 0; }

  // 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;

    }

  }

  // Decode an oop pointer from a narrowOop if compressed.

  // These are overloaded for oop and narrowOop as are the other functions

  // below so that they can be called in template functions.

  static inline oop decode_heap_oop_not_null(oop v) { return v; }

  static inline oop decode_heap_oop_not_null(narrowOop v);

  static inline oop decode_heap_oop(oop v) { return v; }

  static inline oop decode_heap_oop(narrowOop v);

  // Encode an oop pointer to a narrow oop. The or_null versions accept

  // null oop pointer, others do not in order to eliminate the

  // null checking branches.

  static inline narrowOop encode_heap_oop_not_null(oop v);

  static inline narrowOop encode_heap_oop(oop v);

  // Load an oop out of the Java heap as is without decoding.

  // Called by GC to check for null before decoding.

  static inline narrowOop load_heap_oop(narrowOop* p);

  static inline oop       load_heap_oop(oop* p);

  // Load an oop out of Java heap and decode it to an uncompressed oop.

  static inline oop load_decode_heap_oop_not_null(narrowOop* p);

  static inline oop load_decode_heap_oop_not_null(oop* p);

  static inline oop load_decode_heap_oop(narrowOop* p);

  static inline oop load_decode_heap_oop(oop* p);

  // Store already encoded heap oop into the heap.

  static inline void store_heap_oop(narrowOop* p, narrowOop v);

  static inline void store_heap_oop(oop* p, oop v);

  // Encode oop if UseCompressedOops and store into the heap.

  static inline void encode_store_heap_oop_not_null(narrowOop* p, oop v);

  static inline void encode_store_heap_oop_not_null(oop* p, oop v);

  static inline void encode_store_heap_oop(narrowOop* p, oop v);

  static inline void encode_store_heap_oop(oop* p, oop v);

  // 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;

  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;

  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

  void verify_on(outputStream* st);

  void verify();

  // locking operations

  inline bool is_locked()   const;

  inline bool is_unlocked() const;

  inline bool has_bias_pattern() 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);

#ifndef PRODUCT

  inline bool is_unlocked_oop() const;

#endif

  // garbage collection

  inline bool is_gc_marked() const;

  inline bool is_scavengable() const;

  // Forward pointer operations for scavenge

  inline bool is_forwarded() const;

  inline void forward_to(oop p);

  inline bool cas_forward_to(oop p, markOop compare);

#if INCLUDE_ALL_GCS

  // 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);

#endif // INCLUDE_ALL_GCS

  inline oop forwardee() const;

  // Age of object during scavenge

  inline uint age() const;

  inline void incr_age();

  // mark-sweep support

  void follow_body(int begin, int end);

  // Garbage Collection support

#if INCLUDE_ALL_GCS

  // Parallel Compact

  inline void pc_follow_contents(ParCompactionManager* cm);

  inline void pc_update_contents(ParCompactionManager* cm);

  // Parallel Scavenge

  inline void ps_push_contents(PSPromotionManager* pm);

#endif

  // iterators, returns size of object

#define OOP_ITERATE_DECL(OopClosureType, nv_suffix)                     \

  inline void oop_iterate(OopClosureType* blk);                         \

  inline void oop_iterate(OopClosureType* blk, MemRegion mr);  // Only in mr.

  ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DECL)

  ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DECL)

#define OOP_ITERATE_SIZE_DECL(OopClosureType, nv_suffix)                \

  inline int oop_iterate_size(OopClosureType* blk);                     \

  inline int oop_iterate_size(OopClosureType* blk, MemRegion mr);  // Only in mr.

  ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_SIZE_DECL)

  ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_SIZE_DECL)

#if INCLUDE_ALL_GCS

#define OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix)  \

  inline void oop_iterate_backwards(OopClosureType* blk);

  ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DECL)

  ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DECL)

#endif // INCLUDE_ALL_GCS

  inline int oop_iterate_no_header(OopClosure* bk);

  inline int oop_iterate_no_header(OopClosure* bk, MemRegion mr);

  // 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();

  // Alternate hashing code if string table is rehashed

  unsigned int new_hash(juint seed);

  // marks are forwarded to stack when object is locked

  inline bool    has_displaced_mark() const;

  inline markOop displaced_mark() const;

  inline void    set_displaced_mark(markOop m);

  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);

  }

  static bool is_archive_object(oop p) NOT_CDS_JAVA_HEAP_RETURN_(false);

};

#endif // SHARE_VM_OOPS_OOP_HPP