Index: src/mark-compact.h |
=================================================================== |
--- src/mark-compact.h (revision 7267) |
+++ src/mark-compact.h (working copy) |
@@ -28,6 +28,8 @@ |
#ifndef V8_MARK_COMPACT_H_ |
#define V8_MARK_COMPACT_H_ |
+#include "spaces.h" |
+ |
namespace v8 { |
namespace internal { |
@@ -37,23 +39,79 @@ |
typedef bool (*IsAliveFunction)(HeapObject* obj, int* size, int* offset); |
// Forward declarations. |
+class CodeFlusher; |
+class GCTracer; |
+class MarkingVisitor; |
class RootMarkingVisitor; |
-class MarkingVisitor; |
+// ---------------------------------------------------------------------------- |
+// Marking stack for tracing live objects. |
+ |
+class MarkingStack { |
+ public: |
+ MarkingStack() : low_(NULL), top_(NULL), high_(NULL), overflowed_(false) { } |
+ |
+ void Initialize(Address low, Address high) { |
+ top_ = low_ = reinterpret_cast<HeapObject**>(low); |
+ high_ = reinterpret_cast<HeapObject**>(high); |
+ overflowed_ = false; |
+ } |
+ |
+ bool is_full() const { return top_ >= high_; } |
+ |
+ bool is_empty() const { return top_ <= low_; } |
+ |
+ bool overflowed() const { return overflowed_; } |
+ |
+ void clear_overflowed() { overflowed_ = false; } |
+ |
+ // Push the (marked) object on the marking stack if there is room, |
+ // otherwise mark the object as overflowed and wait for a rescan of the |
+ // heap. |
+ void Push(HeapObject* object) { |
+ CHECK(object->IsHeapObject()); |
+ if (is_full()) { |
+ object->SetOverflow(); |
+ overflowed_ = true; |
+ } else { |
+ *(top_++) = object; |
+ } |
+ } |
+ |
+ HeapObject* Pop() { |
+ ASSERT(!is_empty()); |
+ HeapObject* object = *(--top_); |
+ CHECK(object->IsHeapObject()); |
+ return object; |
+ } |
+ |
+ private: |
+ HeapObject** low_; |
+ HeapObject** top_; |
+ HeapObject** high_; |
+ bool overflowed_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(MarkingStack); |
+}; |
+ |
+ |
// ------------------------------------------------------------------------- |
// Mark-Compact collector |
// |
// All methods are static. |
-class MarkCompactCollector: public AllStatic { |
+class OverflowedObjectsScanner; |
+ |
+class MarkCompactCollector { |
public: |
// Type of functions to compute forwarding addresses of objects in |
// compacted spaces. Given an object and its size, return a (non-failure) |
// Object* that will be the object after forwarding. There is a separate |
// allocation function for each (compactable) space based on the location |
// of the object before compaction. |
- typedef MaybeObject* (*AllocationFunction)(HeapObject* object, |
+ typedef MaybeObject* (*AllocationFunction)(Heap* heap, |
+ HeapObject* object, |
int object_size); |
// Type of functions to encode the forwarding address for an object. |
@@ -64,7 +122,8 @@ |
// page as input, and is updated to contain the offset to be used for the |
// next live object in the same page. For spaces using a different |
// encoding (ie, contiguous spaces), the offset parameter is ignored. |
- typedef void (*EncodingFunction)(HeapObject* old_object, |
+ typedef void (*EncodingFunction)(Heap* heap, |
+ HeapObject* old_object, |
int object_size, |
Object* new_object, |
int* offset); |
@@ -72,9 +131,12 @@ |
// Type of functions to process non-live objects. |
typedef void (*ProcessNonLiveFunction)(HeapObject* object); |
+ // Pointer to member function, used in IterateLiveObjects. |
+ typedef int (MarkCompactCollector::*LiveObjectCallback)(HeapObject* obj); |
+ |
// Set the global force_compaction flag, it must be called before Prepare |
// to take effect. |
- static void SetForceCompaction(bool value) { |
+ void SetForceCompaction(bool value) { |
force_compaction_ = value; |
} |
@@ -83,16 +145,16 @@ |
// Prepares for GC by resetting relocation info in old and map spaces and |
// choosing spaces to compact. |
- static void Prepare(GCTracer* tracer); |
+ void Prepare(GCTracer* tracer); |
// Performs a global garbage collection. |
- static void CollectGarbage(); |
+ void CollectGarbage(); |
// True if the last full GC performed heap compaction. |
- static bool HasCompacted() { return compacting_collection_; } |
+ bool HasCompacted() { return compacting_collection_; } |
// True after the Prepare phase if the compaction is taking place. |
- static bool IsCompacting() { |
+ bool IsCompacting() { |
#ifdef DEBUG |
// For the purposes of asserts we don't want this to keep returning true |
// after the collection is completed. |
@@ -104,16 +166,16 @@ |
// The count of the number of objects left marked at the end of the last |
// completed full GC (expected to be zero). |
- static int previous_marked_count() { return previous_marked_count_; } |
+ int previous_marked_count() { return previous_marked_count_; } |
// During a full GC, there is a stack-allocated GCTracer that is used for |
// bookkeeping information. Return a pointer to that tracer. |
- static GCTracer* tracer() { return tracer_; } |
+ GCTracer* tracer() { return tracer_; } |
#ifdef DEBUG |
// Checks whether performing mark-compact collection. |
- static bool in_use() { return state_ > PREPARE_GC; } |
- static bool are_map_pointers_encoded() { return state_ == UPDATE_POINTERS; } |
+ bool in_use() { return state_ > PREPARE_GC; } |
+ bool are_map_pointers_encoded() { return state_ == UPDATE_POINTERS; } |
#endif |
// Determine type of object and emit deletion log event. |
@@ -127,7 +189,16 @@ |
static const uint32_t kSingleFreeEncoding = 0; |
static const uint32_t kMultiFreeEncoding = 1; |
+ inline Heap* heap() const { return heap_; } |
+ |
+ CodeFlusher* code_flusher() { return code_flusher_; } |
+ inline bool is_code_flushing_enabled() const { return code_flusher_ != NULL; } |
+ void EnableCodeFlushing(bool enable); |
+ |
private: |
+ MarkCompactCollector(); |
+ ~MarkCompactCollector(); |
+ |
#ifdef DEBUG |
enum CollectorState { |
IDLE, |
@@ -140,28 +211,28 @@ |
}; |
// The current stage of the collector. |
- static CollectorState state_; |
+ CollectorState state_; |
#endif |
// Global flag that forces a compaction. |
- static bool force_compaction_; |
+ bool force_compaction_; |
// Global flag indicating whether spaces were compacted on the last GC. |
- static bool compacting_collection_; |
+ bool compacting_collection_; |
// Global flag indicating whether spaces will be compacted on the next GC. |
- static bool compact_on_next_gc_; |
+ bool compact_on_next_gc_; |
// The number of objects left marked at the end of the last completed full |
// GC (expected to be zero). |
- static int previous_marked_count_; |
+ int previous_marked_count_; |
// A pointer to the current stack-allocated GC tracer object during a full |
// collection (NULL before and after). |
- static GCTracer* tracer_; |
+ GCTracer* tracer_; |
// Finishes GC, performs heap verification if enabled. |
- static void Finish(); |
+ void Finish(); |
// ----------------------------------------------------------------------- |
// Phase 1: Marking live objects. |
@@ -179,88 +250,82 @@ |
friend class CodeMarkingVisitor; |
friend class SharedFunctionInfoMarkingVisitor; |
- static void PrepareForCodeFlushing(); |
+ void PrepareForCodeFlushing(); |
// Marking operations for objects reachable from roots. |
- static void MarkLiveObjects(); |
+ void MarkLiveObjects(); |
- static void MarkUnmarkedObject(HeapObject* obj); |
+ void MarkUnmarkedObject(HeapObject* obj); |
- static inline void MarkObject(HeapObject* obj) { |
+ inline void MarkObject(HeapObject* obj) { |
if (!obj->IsMarked()) MarkUnmarkedObject(obj); |
} |
- static inline void SetMark(HeapObject* obj) { |
- tracer_->increment_marked_count(); |
-#ifdef DEBUG |
- UpdateLiveObjectCount(obj); |
-#endif |
- obj->SetMark(); |
- } |
+ inline void SetMark(HeapObject* obj); |
// Creates back pointers for all map transitions, stores them in |
// the prototype field. The original prototype pointers are restored |
// in ClearNonLiveTransitions(). All JSObject maps |
// connected by map transitions have the same prototype object, which |
// is why we can use this field temporarily for back pointers. |
- static void CreateBackPointers(); |
+ void CreateBackPointers(); |
// Mark a Map and its DescriptorArray together, skipping transitions. |
- static void MarkMapContents(Map* map); |
- static void MarkDescriptorArray(DescriptorArray* descriptors); |
+ void MarkMapContents(Map* map); |
+ void MarkDescriptorArray(DescriptorArray* descriptors); |
// Mark the heap roots and all objects reachable from them. |
- static void MarkRoots(RootMarkingVisitor* visitor); |
+ void MarkRoots(RootMarkingVisitor* visitor); |
// Mark the symbol table specially. References to symbols from the |
// symbol table are weak. |
- static void MarkSymbolTable(); |
+ void MarkSymbolTable(); |
// Mark objects in object groups that have at least one object in the |
// group marked. |
- static void MarkObjectGroups(); |
+ void MarkObjectGroups(); |
// Mark objects in implicit references groups if their parent object |
// is marked. |
- static void MarkImplicitRefGroups(); |
+ void MarkImplicitRefGroups(); |
// Mark all objects which are reachable due to host application |
// logic like object groups or implicit references' groups. |
- static void ProcessExternalMarking(); |
+ void ProcessExternalMarking(); |
// Mark objects reachable (transitively) from objects in the marking stack |
// or overflowed in the heap. |
- static void ProcessMarkingStack(); |
+ void ProcessMarkingStack(); |
// Mark objects reachable (transitively) from objects in the marking |
// stack. This function empties the marking stack, but may leave |
// overflowed objects in the heap, in which case the marking stack's |
// overflow flag will be set. |
- static void EmptyMarkingStack(); |
+ void EmptyMarkingStack(); |
// Refill the marking stack with overflowed objects from the heap. This |
// function either leaves the marking stack full or clears the overflow |
// flag on the marking stack. |
- static void RefillMarkingStack(); |
+ void RefillMarkingStack(); |
// Callback function for telling whether the object *p is an unmarked |
// heap object. |
static bool IsUnmarkedHeapObject(Object** p); |
#ifdef DEBUG |
- static void UpdateLiveObjectCount(HeapObject* obj); |
+ void UpdateLiveObjectCount(HeapObject* obj); |
#endif |
// We sweep the large object space in the same way whether we are |
// compacting or not, because the large object space is never compacted. |
- static void SweepLargeObjectSpace(); |
+ void SweepLargeObjectSpace(); |
// Test whether a (possibly marked) object is a Map. |
static inline bool SafeIsMap(HeapObject* object); |
// Map transitions from a live map to a dead map must be killed. |
// We replace them with a null descriptor, with the same key. |
- static void ClearNonLiveTransitions(); |
+ void ClearNonLiveTransitions(); |
// ----------------------------------------------------------------------- |
// Phase 2: Sweeping to clear mark bits and free non-live objects for |
@@ -305,32 +370,32 @@ |
// Encodes forwarding addresses of objects in compactable parts of the |
// heap. |
- static void EncodeForwardingAddresses(); |
+ void EncodeForwardingAddresses(); |
// Encodes the forwarding addresses of objects in new space. |
- static void EncodeForwardingAddressesInNewSpace(); |
+ void EncodeForwardingAddressesInNewSpace(); |
// Function template to encode the forwarding addresses of objects in |
// paged spaces, parameterized by allocation and non-live processing |
// functions. |
template<AllocationFunction Alloc, ProcessNonLiveFunction ProcessNonLive> |
- static void EncodeForwardingAddressesInPagedSpace(PagedSpace* space); |
+ void EncodeForwardingAddressesInPagedSpace(PagedSpace* space); |
// Iterates live objects in a space, passes live objects |
// to a callback function which returns the heap size of the object. |
// Returns the number of live objects iterated. |
- static int IterateLiveObjects(NewSpace* space, HeapObjectCallback size_f); |
- static int IterateLiveObjects(PagedSpace* space, HeapObjectCallback size_f); |
+ int IterateLiveObjects(NewSpace* space, LiveObjectCallback size_f); |
+ int IterateLiveObjects(PagedSpace* space, LiveObjectCallback size_f); |
// Iterates the live objects between a range of addresses, returning the |
// number of live objects. |
- static int IterateLiveObjectsInRange(Address start, Address end, |
- HeapObjectCallback size_func); |
+ int IterateLiveObjectsInRange(Address start, Address end, |
+ LiveObjectCallback size_func); |
// If we are not compacting the heap, we simply sweep the spaces except |
// for the large object space, clearing mark bits and adding unmarked |
// regions to each space's free list. |
- static void SweepSpaces(); |
+ void SweepSpaces(); |
// ----------------------------------------------------------------------- |
// Phase 3: Updating pointers in live objects. |
@@ -344,15 +409,15 @@ |
friend class UpdatingVisitor; // helper for updating visited objects |
// Updates pointers in all spaces. |
- static void UpdatePointers(); |
+ void UpdatePointers(); |
// Updates pointers in an object in new space. |
// Returns the heap size of the object. |
- static int UpdatePointersInNewObject(HeapObject* obj); |
+ int UpdatePointersInNewObject(HeapObject* obj); |
// Updates pointers in an object in old spaces. |
// Returns the heap size of the object. |
- static int UpdatePointersInOldObject(HeapObject* obj); |
+ int UpdatePointersInOldObject(HeapObject* obj); |
// Calculates the forwarding address of an object in an old space. |
static Address GetForwardingAddressInOldSpace(HeapObject* obj); |
@@ -366,31 +431,31 @@ |
// After: Objects have been moved to their new addresses. |
// Relocates objects in all spaces. |
- static void RelocateObjects(); |
+ void RelocateObjects(); |
// Converts a code object's inline target to addresses, convention from |
// address to target happens in the marking phase. |
- static int ConvertCodeICTargetToAddress(HeapObject* obj); |
+ int ConvertCodeICTargetToAddress(HeapObject* obj); |
// Relocate a map object. |
- static int RelocateMapObject(HeapObject* obj); |
+ int RelocateMapObject(HeapObject* obj); |
// Relocates an old object. |
- static int RelocateOldPointerObject(HeapObject* obj); |
- static int RelocateOldDataObject(HeapObject* obj); |
+ int RelocateOldPointerObject(HeapObject* obj); |
+ int RelocateOldDataObject(HeapObject* obj); |
// Relocate a property cell object. |
- static int RelocateCellObject(HeapObject* obj); |
+ int RelocateCellObject(HeapObject* obj); |
// Helper function. |
- static inline int RelocateOldNonCodeObject(HeapObject* obj, |
- PagedSpace* space); |
+ inline int RelocateOldNonCodeObject(HeapObject* obj, |
+ PagedSpace* space); |
// Relocates an object in the code space. |
- static int RelocateCodeObject(HeapObject* obj); |
+ int RelocateCodeObject(HeapObject* obj); |
// Copy a new object. |
- static int RelocateNewObject(HeapObject* obj); |
+ int RelocateNewObject(HeapObject* obj); |
#ifdef DEBUG |
// ----------------------------------------------------------------------- |
@@ -399,28 +464,28 @@ |
// mark-sweep collection. |
// Size of live objects in Heap::to_space_. |
- static int live_young_objects_size_; |
+ int live_young_objects_size_; |
// Size of live objects in Heap::old_pointer_space_. |
- static int live_old_pointer_objects_size_; |
+ int live_old_pointer_objects_size_; |
// Size of live objects in Heap::old_data_space_. |
- static int live_old_data_objects_size_; |
+ int live_old_data_objects_size_; |
// Size of live objects in Heap::code_space_. |
- static int live_code_objects_size_; |
+ int live_code_objects_size_; |
// Size of live objects in Heap::map_space_. |
- static int live_map_objects_size_; |
+ int live_map_objects_size_; |
// Size of live objects in Heap::cell_space_. |
- static int live_cell_objects_size_; |
+ int live_cell_objects_size_; |
// Size of live objects in Heap::lo_space_. |
- static int live_lo_objects_size_; |
+ int live_lo_objects_size_; |
// Number of live bytes in this collection. |
- static int live_bytes_; |
+ int live_bytes_; |
friend class MarkObjectVisitor; |
static void VisitObject(HeapObject* obj); |
@@ -428,6 +493,13 @@ |
friend class UnmarkObjectVisitor; |
static void UnmarkObject(HeapObject* obj); |
#endif |
+ |
+ Heap* heap_; |
+ MarkingStack marking_stack_; |
+ CodeFlusher* code_flusher_; |
+ |
+ friend class Heap; |
+ friend class OverflowedObjectsScanner; |
}; |