hotspot/src/share/vm/oops/oop.hpp - platform/libcore - Git at Google

 /*
  * Copyright 1997-2007 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
 void oop_store(oop* p, oop v);
 void oop_store(volatile oop* p, oop v);

 // store into oop without store check
 void oop_store_without_check(oop* p, oop v);
 void oop_store_without_check(volatile oop* 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;
   klassOop _klass;

   // 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        { return _klass; }
   oop* klass_addr() const       { return (oop*) &_klass; }

   void set_klass(klassOop k);
   // 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
   static int header_size()      { return sizeof(oopDesc)/HeapWordSize; }
   static int header_size_in_bytes() { return sizeof(oopDesc); }

   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();

   // 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
   // byte/char/bool/short fields are always stored as full words
   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;

  public:
   // need this as public for garbage collection
   oop* obj_field_addr(int offset) const;

   oop obj_field(int offset) const;
   void obj_field_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);

   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);

   // 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 follow_header();

 #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_3(OOP_ITERATE_DECL)

   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 klass_offset_in_bytes()   { return offset_of(oopDesc, _klass); }
   static int mark_offset_in_bytes()    { return offset_of(oopDesc, _mark); }
 };
	/*
	* Copyright 1997-2007 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
	void oop_store(oop* p, oop v);
	void oop_store(volatile oop* p, oop v);

	// store into oop without store check
	void oop_store_without_check(oop* p, oop v);
	void oop_store_without_check(volatile oop* 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;
	klassOop _klass;

	// 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 { return _klass; }
	oop* klass_addr() const { return (oop*) &_klass; }

	void set_klass(klassOop k);
	// 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
	static int header_size() { return sizeof(oopDesc)/HeapWordSize; }
	static int header_size_in_bytes() { return sizeof(oopDesc); }

	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();

	// 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
	// byte/char/bool/short fields are always stored as full words
	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;

	public:
	// need this as public for garbage collection
	oop* obj_field_addr(int offset) const;

	oop obj_field(int offset) const;
	void obj_field_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);

	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);

	// 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 follow_header();

	#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_3(OOP_ITERATE_DECL)

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