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// Copyright 2011 Google Inc. All Rights Reserved.
#ifndef ART_SRC_MARK_SWEEP_H_
#define ART_SRC_MARK_SWEEP_H_
#include "macros.h"
#include "mark_stack.h"
#include "heap_bitmap.h"
#include "offsets.h"
namespace art {
class Class;
class Object;
class MarkSweep {
public:
MarkSweep() :
finger_(NULL),
condemned_(NULL),
soft_reference_list_(NULL),
weak_reference_list_(NULL),
finalizer_reference_list_(NULL),
phantom_reference_list_(NULL),
cleared_reference_list_(NULL),
class_count_(0), array_count_(0), other_count_(0) {
}
~MarkSweep();
// Initializes internal structures.
void Init();
// Marks the root set at the start of a garbage collection.
void MarkRoots();
// Marks the roots in the image space on dirty cards
void ScanDirtyImageRoots();
bool IsMarkStackEmpty() const {
return mark_stack_->IsEmpty();
}
// Builds a mark stack and recursively mark until it empties.
void RecursiveMark();
// Remarks the root set after completing the concurrent mark.
void ReMarkRoots();
void ProcessReferences(bool clear_soft_references) {
ProcessReferences(&soft_reference_list_, clear_soft_references,
&weak_reference_list_,
&finalizer_reference_list_,
&phantom_reference_list_);
}
// Sweeps unmarked objects to complete the garbage collection.
void Sweep();
Object* GetClearedReferences() {
return cleared_reference_list_;
}
private:
// Returns true if the object has its bit set in the mark bitmap.
bool IsMarked(const Object* object) const {
return mark_bitmap_->Test(object);
}
static bool IsMarked(const Object* object, void* arg) {
return reinterpret_cast<MarkSweep*>(arg)->IsMarked(object);
}
static void MarkObjectVisitor(const Object* root, void* arg);
static void ScanImageRootVisitor(Object* root, void* arg);
// Marks an object.
void MarkObject(const Object* obj);
// Yuck.
void MarkObject0(const Object* obj, bool check_finger);
static void ScanBitmapCallback(Object* obj, void* finger, void* arg);
static void CheckBitmapCallback(Object* obj, void* finger, void* arg);
static void SweepCallback(size_t num_ptrs, void** ptrs, void* arg);
void CheckReference(const Object* obj, const Object* ref, MemberOffset offset, bool is_static);
// Blackens an object.
void ScanObject(const Object* obj);
void CheckObject(const Object* obj);
// Grays references in instance fields.
void ScanInstanceFields(const Object* obj);
void CheckInstanceFields(const Object* obj);
// Blackens a class object.
void ScanClass(const Object* obj);
void CheckClass(const Object* obj);
// Grays references in static fields.
void ScanStaticFields(const Class* klass);
void CheckStaticFields(const Class* klass);
// Used by ScanInstanceFields and ScanStaticFields
void ScanFields(const Object* obj, uint32_t ref_offsets, bool is_static);
void CheckFields(const Object* obj, uint32_t ref_offsets, bool is_static);
// Grays references in an array.
void ScanArray(const Object* obj);
void CheckArray(const Object* obj);
void ScanOther(const Object* obj);
void CheckOther(const Object* obj);
// Blackens objects grayed during a garbage collection.
void ScanDirtyObjects();
// Schedules an unmarked object for reference processing.
void DelayReferenceReferent(Object* reference);
// Recursively blackens objects on the mark stack.
void ProcessMarkStack();
void EnqueueFinalizerReferences(Object** ref);
void PreserveSomeSoftReferences(Object** ref);
void ClearWhiteReferences(Object** list);
void ProcessReferences(Object** soft_references, bool clear_soft_references,
Object** weak_references,
Object** finalizer_references,
Object** phantom_references);
void SweepSystemWeaks();
void SweepJniWeakGlobals();
MarkStack* mark_stack_;
HeapBitmap* mark_bitmap_;
HeapBitmap* live_bitmap_;
Object* finger_;
Object* condemned_;
Object* soft_reference_list_;
Object* weak_reference_list_;
Object* finalizer_reference_list_;
Object* phantom_reference_list_;
Object* cleared_reference_list_;
size_t class_count_;
size_t array_count_;
size_t other_count_;
friend class InternTableEntryIsUnmarked;
DISALLOW_COPY_AND_ASSIGN(MarkSweep);
};
} // namespace art
#endif // ART_SRC_MARK_SWEEP_H_
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