/*

 * Copyright 1997-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

// 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

// store into oop with store check

template <class T> void oop_store(T* p, oop v);

template <class T> void oop_store(volatile T* p, oop v);

// store into oop without store check

template <class T> void oop_store_without_check(T* p, oop v);

template <class T> void oop_store_without_check(volatile T* p, oop v);

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;

 private:

  volatile markOop  _mark;

  union _metadata {

    wideKlassOop    _klass;

    narrowOop       _compressed_klass;

  } _metadata;

  // Fast access to barrier set.  Must be initialized.

  static BarrierSet* _bs;

 public:

  markOop  mark() const         { return _mark; }

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

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

  void    release_set_mark(markOop m);

  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

  void init_mark();

  klassOop klass() const;

  klassOop klass_or_null() const volatile;

  oop* klass_addr();

  narrowOop* compressed_klass_addr();

  void set_klass(klassOop k);

  // For klass field compression

  int klass_gap() const;

  void set_klass_gap(int z);

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

  void set_klass_to_list_ptr(oop k);

  // size of object header, aligned to platform wordSize

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

  Klass* blueprint() const;

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

  bool is_a(klassOop k)  const;

  // Returns the actual oop size of the object

  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.

  int size_given_klass(Klass* klass);

  // Some perm gen objects are not parseble immediately after

  // installation of their klass pointer.

  bool is_parsable();

  // Some perm gen objects that have been allocated and initialized

  // can be changed by the VM when not at a safe point (class rededfinition

  // is an example).  Such objects should not be examined by the

  // concurrent processing of a garbage collector if is_conc_safe()

  // returns false.

  bool is_conc_safe();

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

  bool is_instance()           const;

  bool is_instanceRef()        const;

  bool is_array()              const;

  bool is_objArray()           const;

  bool is_symbol()             const;

  bool is_klass()              const;

  bool is_thread()             const;

  bool is_method()             const;

  bool is_constMethod()        const;

  bool is_methodData()         const;

  bool is_constantPool()       const;

  bool is_constantPoolCache()  const;

  bool is_typeArray()          const;

  bool is_javaArray()          const;

  bool is_compiledICHolder()   const;

 private:

  // field addresses in oop

  void*     field_base(int offset)        const;

  jbyte*    byte_field_addr(int offset)   const;

  jchar*    char_field_addr(int offset)   const;

  jboolean* bool_field_addr(int offset)   const;

  jint*     int_field_addr(int offset)    const;

  jshort*   short_field_addr(int offset)  const;

  jlong*    long_field_addr(int offset)   const;

  jfloat*   float_field_addr(int offset)  const;

  jdouble*  double_field_addr(int offset) const;

  address*  address_field_addr(int offset) const;

 public:

  // Need this as public for garbage collection.

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

  // Oop encoding heap max

  static const uint64_t OopEncodingHeapMax =

              (uint64_t(max_juint) + 1) << LogMinObjAlignmentInBytes;

  static bool is_null(oop obj);

  static bool is_null(narrowOop obj);

  // 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 oop decode_heap_oop_not_null(oop v);

  static oop decode_heap_oop_not_null(narrowOop v);

  static oop decode_heap_oop(oop v);

  static 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 narrowOop encode_heap_oop_not_null(oop v);

  static narrowOop encode_heap_oop(oop v);

  // Load an oop out of the Java heap

  static narrowOop load_heap_oop(narrowOop* p);

  static oop       load_heap_oop(oop* p);

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

  static oop load_decode_heap_oop_not_null(narrowOop* p);

  static oop load_decode_heap_oop_not_null(oop* p);

  static oop load_decode_heap_oop(narrowOop* p);

  static oop load_decode_heap_oop(oop* p);

  // Store an oop into the heap.

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

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

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

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

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

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

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

  static void release_store_heap_oop(volatile narrowOop* p, narrowOop v);

  static void release_store_heap_oop(volatile oop* p, oop v);

  static void release_encode_store_heap_oop_not_null(volatile narrowOop* p, oop v);

  static void release_encode_store_heap_oop_not_null(volatile oop* p, oop v);

  static void release_encode_store_heap_oop(volatile narrowOop* p, oop v);

  static void release_encode_store_heap_oop(volatile oop* p, oop v);

  static oop atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest);

  static oop atomic_compare_exchange_oop(oop exchange_value,

                                         volatile HeapWord *dest,

                                         oop compare_value);

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

  oop obj_field(int offset) const;

  void obj_field_put(int offset, oop value);

  void obj_field_raw_put(int offset, oop 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);

  // 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();

  void verify_old_oop(oop* p, bool allow_dirty);

  void verify_old_oop(narrowOop* p, bool allow_dirty);

  // tells whether this oop is partially constructed (gc during class loading)

  bool partially_loaded();

  void set_partially_loaded();

  // locking operations

  bool is_locked()   const;

  bool is_unlocked() const;

  bool has_bias_pattern() const;

  // asserts

  bool is_oop(bool ignore_mark_word = false) const;

  bool is_oop_or_null(bool ignore_mark_word = false) const;

#ifndef PRODUCT

  bool is_unlocked_oop() const;

#endif

  // garbage collection

  bool is_gc_marked() const;

  // Apply "MarkSweep::mark_and_push" to (the address of) every non-NULL

  // reference field in "this".

  void follow_contents(void);

  void follow_header(void);

#ifndef SERIALGC

  // Parallel Scavenge

  void copy_contents(PSPromotionManager* pm);

  void push_contents(PSPromotionManager* pm);

  // Parallel Old

  void update_contents(ParCompactionManager* cm);

  void update_contents(ParCompactionManager* cm,

                       HeapWord* begin_limit,

                       HeapWord* end_limit);

  void update_contents(ParCompactionManager* cm,

                       klassOop old_klass,

                       HeapWord* begin_limit,

                       HeapWord* end_limit);

  void follow_contents(ParCompactionManager* cm);

  void follow_header(ParCompactionManager* cm);

#endif // SERIALGC

  bool is_perm() const;

  bool is_perm_or_null() const;

  bool is_shared() const;

  bool is_shared_readonly() const;

  bool is_shared_readwrite() const;

  // Forward pointer operations for scavenge

  bool is_forwarded() const;

  void forward_to(oop p);

  bool cas_forward_to(oop p, markOop compare);

#ifndef SERIALGC

  // 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".

  oop forward_to_atomic(oop p);

#endif // SERIALGC

  oop forwardee() const;

  // Age of object during scavenge

  int age() const;

  void incr_age();

  // Adjust all pointers in this object to point at it's forwarded location and

  // return the size of this oop.  This is used by the MarkSweep collector.

  int adjust_pointers();

  void adjust_header();

#ifndef SERIALGC

  // Parallel old

  void update_header();

  void update_header(HeapWord* beg_addr, HeapWord* end_addr);

#endif // SERIALGC

  // mark-sweep support

  void follow_body(int begin, int end);

  // Fast access to barrier set

  static BarrierSet* bs()            { return _bs; }

  static void set_bs(BarrierSet* bs) { _bs = bs; }

  // iterators, returns size of object

#define OOP_ITERATE_DECL(OopClosureType, nv_suffix)                      \

  int oop_iterate(OopClosureType* blk);                                  \

  int 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)

#ifndef SERIALGC

#define OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix)            \

  int 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

  void oop_iterate_header(OopClosure* blk);

  void oop_iterate_header(OopClosure* blk, 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.

  intptr_t identity_hash();

  intptr_t slow_identity_hash();

  // marks are forwarded to stack when object is locked

  bool     has_displaced_mark() const;

  markOop  displaced_mark() const;

  void     set_displaced_mark(markOop m);

  // 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();

};