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 /*

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

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  * 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_VM_MEMORY_GENOOPCLOSURES_HPP

 #define SHARE_VM_MEMORY_GENOOPCLOSURES_HPP

 #include "memory/iterator.hpp"

 #include "oops/oop.hpp"

 class Generation;

 class HeapWord;

 class CardTableRS;

 class CardTableModRefBS;

 class DefNewGeneration;

 class KlassRemSet;

 template<class E, MEMFLAGS F, unsigned int N> class GenericTaskQueue;

 typedef GenericTaskQueue<oop, mtGC, TASKQUEUE_SIZE> OopTaskQueue;

 template<class T, MEMFLAGS F> class GenericTaskQueueSet;

 typedef GenericTaskQueueSet<OopTaskQueue, mtGC> OopTaskQueueSet;

 // Closure for iterating roots from a particular generation

 // Note: all classes deriving from this MUST call this do_barrier

 // method at the end of their own do_oop method!

 // Note: no do_oop defined, this is an abstract class.

 class OopsInGenClosure : public ExtendedOopClosure {

  private:

   Generation*  _orig_gen;     // generation originally set in ctor

   Generation*  _gen;          // generation being scanned

  protected:

   // Some subtypes need access.

   HeapWord*    _gen_boundary; // start of generation

   CardTableRS* _rs;           // remembered set

   // For assertions

   Generation* generation() { return _gen; }

   CardTableRS* rs() { return _rs; }

   // Derived classes that modify oops so that they might be old-to-young

   // pointers must call the method below.

   template <class T> void do_barrier(T* p);

   // Version for use by closures that may be called in parallel code.

   template <class T> void par_do_barrier(T* p);

  public:

   OopsInGenClosure() : ExtendedOopClosure(NULL),

     _orig_gen(NULL), _gen(NULL), _gen_boundary(NULL), _rs(NULL) {};

   OopsInGenClosure(Generation* gen);

   void set_generation(Generation* gen);

   void reset_generation() { _gen = _orig_gen; }

   // Problem with static closures: must have _gen_boundary set at some point,

   // but cannot do this until after the heap is initialized.

   void set_orig_generation(Generation* gen) {

     _orig_gen = gen;

     set_generation(gen);

   }

   HeapWord* gen_boundary() { return _gen_boundary; }

 };

 // Super class for scan closures. It contains code to dirty scanned Klasses.

 class OopsInKlassOrGenClosure: public OopsInGenClosure {

   Klass* _scanned_klass;

  public:

   OopsInKlassOrGenClosure(Generation* g) : OopsInGenClosure(g), _scanned_klass(NULL) {}

   void set_scanned_klass(Klass* k) {

     assert(k == NULL || _scanned_klass == NULL, "Must be");

     _scanned_klass = k;

   }

   bool is_scanning_a_klass() { return _scanned_klass != NULL; }

   void do_klass_barrier();

 };

 // Closure for scanning DefNewGeneration.

 //

 // This closure will perform barrier store calls for ALL

 // pointers in scanned oops.

 class ScanClosure: public OopsInKlassOrGenClosure {

  protected:

   DefNewGeneration* _g;

   HeapWord*         _boundary;

   bool              _gc_barrier;

   template <class T> inline void do_oop_work(T* p);

  public:

   ScanClosure(DefNewGeneration* g, bool gc_barrier);

   virtual void do_oop(oop* p);

   virtual void do_oop(narrowOop* p);

   inline void do_oop_nv(oop* p);

   inline void do_oop_nv(narrowOop* p);

   Prefetch::style prefetch_style() {

     return Prefetch::do_write;

   }

 };

 // Closure for scanning DefNewGeneration.

 //

 // This closure only performs barrier store calls on

 // pointers into the DefNewGeneration. This is less

 // precise, but faster, than a ScanClosure

 class FastScanClosure: public OopsInKlassOrGenClosure {

  protected:

   DefNewGeneration* _g;

   HeapWord*         _boundary;

   bool              _gc_barrier;

   template <class T> inline void do_oop_work(T* p);

  public:

   FastScanClosure(DefNewGeneration* g, bool gc_barrier);

   virtual void do_oop(oop* p);

   virtual void do_oop(narrowOop* p);

   inline void do_oop_nv(oop* p);

   inline void do_oop_nv(narrowOop* p);

   Prefetch::style prefetch_style() {

     return Prefetch::do_write;

   }

 };

 class KlassScanClosure: public KlassClosure {

   OopsInKlassOrGenClosure* _scavenge_closure;

   // true if the the modified oops state should be saved.

   bool                     _accumulate_modified_oops;

  public:

   KlassScanClosure(OopsInKlassOrGenClosure* scavenge_closure,

                    KlassRemSet* klass_rem_set_policy);

   void do_klass(Klass* k);

 };

 class FilteringClosure: public ExtendedOopClosure {

  private:

   HeapWord*   _boundary;

   ExtendedOopClosure* _cl;

  protected:

   template <class T> inline void do_oop_work(T* p) {

     T heap_oop = oopDesc::load_heap_oop(p);

     if (!oopDesc::is_null(heap_oop)) {

       oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);

       if ((HeapWord*)obj < _boundary) {

         _cl->do_oop(p);

       }

     }

   }

  public:

   FilteringClosure(HeapWord* boundary, ExtendedOopClosure* cl) :

     ExtendedOopClosure(cl->_ref_processor), _boundary(boundary),

     _cl(cl) {}

   virtual void do_oop(oop* p);

   virtual void do_oop(narrowOop* p);

   inline void do_oop_nv(oop* p)       { FilteringClosure::do_oop_work(p); }

   inline void do_oop_nv(narrowOop* p) { FilteringClosure::do_oop_work(p); }

   virtual bool do_metadata()          { return do_metadata_nv(); }

   inline bool do_metadata_nv()        { assert(!_cl->do_metadata(), "assumption broken, must change to 'return _cl->do_metadata()'"); return false; }

 };

 // Closure for scanning DefNewGeneration's weak references.

 // NOTE: very much like ScanClosure but not derived from

 //  OopsInGenClosure -- weak references are processed all

 //  at once, with no notion of which generation they were in.

 class ScanWeakRefClosure: public OopClosure {

  protected:

   DefNewGeneration* _g;

   HeapWord*         _boundary;

   template <class T> inline void do_oop_work(T* p);

  public:

   ScanWeakRefClosure(DefNewGeneration* g);

   virtual void do_oop(oop* p);

   virtual void do_oop(narrowOop* p);

   inline void do_oop_nv(oop* p);

   inline void do_oop_nv(narrowOop* p);

 };

 class VerifyOopClosure: public OopClosure {

  protected:

   template <class T> inline void do_oop_work(T* p) {

     oop obj = oopDesc::load_decode_heap_oop(p);

     guarantee(obj->is_oop_or_null(), err_msg("invalid oop: " INTPTR_FORMAT, (oopDesc*) obj));

   }

  public:

   virtual void do_oop(oop* p);

   virtual void do_oop(narrowOop* p);

   static VerifyOopClosure verify_oop;

 };

 #endif // SHARE_VM_MEMORY_GENOOPCLOSURES_HPP