#ifndef SHARE_VM_MEMORY_GENREMSET_HPP

#define SHARE_VM_MEMORY_GENREMSET_HPP

#include "oops/oop.hpp"

class Generation;

class BarrierSet;

class OopsInGenClosure;

class CardTableRS;

class GenRemSet: public CHeapObj<mtGC> {

friend class Generation;

BarrierSet* _bs;

public:

enum Name {

CardTable,

Other

};

GenRemSet(BarrierSet * bs) : _bs(bs) {}

GenRemSet() : _bs(NULL) {}

virtual Name rs_kind() = 0;

// These are for dynamic downcasts. Unfortunately that it names the

// possible subtypes (but not that they are subtypes!) Return NULL if

// the cast is invalide.

virtual CardTableRS* as_CardTableRS() { return NULL; }

// Return the barrier set associated with "this."

BarrierSet* bs() { return _bs; }

// Set the barrier set.

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

// Do any (sequential) processing necessary to prepare for (possibly

// "parallel", if that arg is true) calls to younger_refs_iterate.

virtual void prepare_for_younger_refs_iterate(bool parallel) = 0;

// Apply the "do_oop" method of "blk" to (exactly) all oop locations

// 1) that are in objects allocated in "g" at the time of the last call

// to "save_Marks", and

// 2) that point to objects in younger generations.

virtual void younger_refs_iterate(Generation* g, OopsInGenClosure* blk) = 0;

virtual void younger_refs_in_space_iterate(Space* sp,

OopsInGenClosure* cl) = 0;

// This method is used to notify the remembered set that "new_val" has

// been written into "field" by the garbage collector.

void write_ref_field_gc(void* field, oop new_val);

protected:

virtual void write_ref_field_gc_work(void* field, oop new_val) = 0;

public:

// A version of the above suitable for use by parallel collectors.

virtual void write_ref_field_gc_par(void* field, oop new_val) = 0;

// Resize one of the regions covered by the remembered set.

virtual void resize_covered_region(MemRegion new_region) = 0;

// If the rem set imposes any alignment restrictions on boundaries

// within the heap, this function tells whether they are met.

virtual bool is_aligned(HeapWord* addr) = 0;

// If the RS (or BS) imposes an aligment constraint on maximum heap size.

// (This must be static, and dispatch on "nm", because it is called

// before an RS is created.)

static uintx max_alignment_constraint(Name nm);

virtual void verify() = 0;

// Verify that the remembered set has no entries for

// the heap interval denoted by mr. If there are any

// alignment constraints on the remembered set, only the

// part of the region that is aligned is checked.

//

// alignment boundaries

// +--------+-------+--------+-------+

// [ region mr )

// [ part checked )

virtual void verify_aligned_region_empty(MemRegion mr) = 0;

// If appropriate, print some information about the remset on "tty".

virtual void print() {}

// Informs the RS that the given memregion contains no references to

// younger generations.

virtual void clear(MemRegion mr) = 0;

// Informs the RS that there are no references to generations

// younger than gen from generations gen and older.

// The parameter clear_perm indicates if the perm_gen's

// remembered set should also be processed/cleared.

virtual void clear_into_younger(Generation* gen, bool clear_perm) = 0;

// Informs the RS that refs in the given "mr" may have changed

// arbitrarily, and therefore may contain old-to-young pointers.

// If "whole heap" is true, then this invalidation is part of an

// invalidation of the whole heap, which an implementation might

// handle differently than that of a sub-part of the heap.

virtual void invalidate(MemRegion mr, bool whole_heap = false) = 0;

// Informs the RS that refs in this generation

// may have changed arbitrarily, and therefore may contain

// old-to-young pointers in arbitrary locations. The parameter

// younger indicates if the same should be done for younger generations

// as well. The parameter perm indicates if the same should be done for

// perm gen as well.

virtual void invalidate_or_clear(Generation* gen, bool younger, bool perm) = 0;

};

#endif // SHARE_VM_MEMORY_GENREMSET_HPP