diff options
author | Ryan Dahl <ry@tinyclouds.org> | 2011-07-08 16:40:11 -0700 |
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committer | Ryan Dahl <ry@tinyclouds.org> | 2011-07-08 16:40:11 -0700 |
commit | e5564a3f29e0a818832a97c7c3b28d7c8b3b0460 (patch) | |
tree | 4b48a6577080d5e44da4d2cbebb7fe7951660de8 /deps/v8/src/mark-compact.h | |
parent | 0df2f74d364826053641395b01c2fcb1345057a9 (diff) | |
download | node-e5564a3f29e0a818832a97c7c3b28d7c8b3b0460.tar.gz |
Upgrade V8 to 3.4.10
Diffstat (limited to 'deps/v8/src/mark-compact.h')
-rw-r--r-- | deps/v8/src/mark-compact.h | 237 |
1 files changed, 157 insertions, 80 deletions
diff --git a/deps/v8/src/mark-compact.h b/deps/v8/src/mark-compact.h index 1b7e60022..179edba74 100644 --- a/deps/v8/src/mark-compact.h +++ b/deps/v8/src/mark-compact.h @@ -28,6 +28,8 @@ #ifndef V8_MARK_COMPACT_H_ #define V8_MARK_COMPACT_H_ +#include "spaces.h" + namespace v8 { namespace internal { @@ -37,23 +39,77 @@ namespace internal { typedef bool (*IsAliveFunction)(HeapObject* obj, int* size, int* offset); // Forward declarations. -class RootMarkingVisitor; +class CodeFlusher; +class GCTracer; class MarkingVisitor; +class RootMarkingVisitor; + + +// ---------------------------------------------------------------------------- +// 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. @@ -64,17 +120,21 @@ class MarkCompactCollector: public AllStatic { // 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); // Type of functions to process non-live objects. - typedef void (*ProcessNonLiveFunction)(HeapObject* object); + typedef void (*ProcessNonLiveFunction)(HeapObject* object, Isolate* isolate); + + // 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 +143,16 @@ class MarkCompactCollector: public AllStatic { // 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. @@ -104,20 +164,20 @@ class MarkCompactCollector: public AllStatic { // 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. - static void ReportDeleteIfNeeded(HeapObject* obj); + static void ReportDeleteIfNeeded(HeapObject* obj, Isolate* isolate); // Returns size of a possibly marked object. static int SizeOfMarkedObject(HeapObject* obj); @@ -127,7 +187,16 @@ class MarkCompactCollector: public AllStatic { 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 +209,28 @@ class MarkCompactCollector: public AllStatic { }; // 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. @@ -179,85 +248,86 @@ class MarkCompactCollector: public AllStatic { 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 all objects in an object group with at least one marked - // object, then all objects reachable from marked objects in object - // groups, and repeat. - static void ProcessObjectGroups(); + // Mark objects in implicit references groups if their parent object + // is marked. + void MarkImplicitRefGroups(); + + // Mark all objects which are reachable due to host application + // logic like object groups or implicit references' groups. + 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(); + + // After reachable maps have been marked process per context object + // literal map caches removing unmarked entries. + void ProcessMapCaches(); // 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 @@ -302,32 +372,32 @@ class MarkCompactCollector: public AllStatic { // 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. @@ -341,15 +411,15 @@ class MarkCompactCollector: public AllStatic { 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); @@ -363,31 +433,31 @@ class MarkCompactCollector: public AllStatic { // 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 // ----------------------------------------------------------------------- @@ -396,28 +466,28 @@ class MarkCompactCollector: public AllStatic { // 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); @@ -425,6 +495,13 @@ class MarkCompactCollector: public AllStatic { friend class UnmarkObjectVisitor; static void UnmarkObject(HeapObject* obj); #endif + + Heap* heap_; + MarkingStack marking_stack_; + CodeFlusher* code_flusher_; + + friend class Heap; + friend class OverflowedObjectsScanner; }; |