Index: src/heap/store-buffer.h |
diff --git a/src/heap/store-buffer.h b/src/heap/store-buffer.h |
index f5af09904d99aebac2d9ad3a9ec4ce0784c2e46e..9670f62a8a9a1d55a96c374cab1ba7660710d5c2 100644 |
--- a/src/heap/store-buffer.h |
+++ b/src/heap/store-buffer.h |
@@ -9,6 +9,7 @@ |
#include "src/base/logging.h" |
#include "src/base/platform/platform.h" |
#include "src/globals.h" |
+#include "src/heap/slot-set.h" |
namespace v8 { |
namespace internal { |
@@ -24,66 +25,22 @@ typedef void (*ObjectSlotCallback)(HeapObject** from, HeapObject* to); |
class StoreBuffer { |
public: |
explicit StoreBuffer(Heap* heap); |
- |
static void StoreBufferOverflow(Isolate* isolate); |
- |
void SetUp(); |
void TearDown(); |
- // This is used to add addresses to the store buffer non-concurrently. |
- inline void Mark(Address addr); |
- |
- // This is used by the heap traversal to enter the addresses into the store |
- // buffer that should still be in the store buffer after GC. It enters |
- // addresses directly into the old buffer because the GC starts by wiping the |
- // old buffer and thereafter only visits each cell once so there is no need |
- // to attempt to remove any dupes. During the first part of a GC we |
- // are using the store buffer to access the old spaces and at the same time |
- // we are rebuilding the store buffer using this function. There is, however |
- // no issue of overwriting the buffer we are iterating over, because this |
- // stage of the scavenge can only reduce the number of addresses in the store |
- // buffer (some objects are promoted so pointers to them do not need to be in |
- // the store buffer). The later parts of the GC scan the pages that are |
- // exempt from the store buffer and process the promotion queue. These steps |
- // can overflow this buffer. We check for this and on overflow we call the |
- // callback set up with the StoreBufferRebuildScope object. |
- inline void EnterDirectlyIntoStoreBuffer(Address addr); |
- |
- // Iterates over all pointers that go from old space to new space. It will |
- // delete the store buffer as it starts so the callback should reenter |
- // surviving old-to-new pointers into the store buffer to rebuild it. |
- void IteratePointersToNewSpace(ObjectSlotCallback callback); |
- |
static const int kStoreBufferOverflowBit = 1 << (14 + kPointerSizeLog2); |
static const int kStoreBufferSize = kStoreBufferOverflowBit; |
static const int kStoreBufferLength = kStoreBufferSize / sizeof(Address); |
- static const int kOldStoreBufferLength = kStoreBufferLength * 16; |
- static const int kHashSetLengthLog2 = 12; |
- static const int kHashSetLength = 1 << kHashSetLengthLog2; |
- |
- void Compact(); |
- |
- void GCPrologue(); |
- void GCEpilogue(); |
- |
- Object*** Limit() { return reinterpret_cast<Object***>(old_limit_); } |
- Object*** Start() { return reinterpret_cast<Object***>(old_start_); } |
- Object*** Top() { return reinterpret_cast<Object***>(old_top_); } |
- void SetTop(Object*** top) { |
- DCHECK(top >= Start()); |
- DCHECK(top <= Limit()); |
- old_top_ = reinterpret_cast<Address*>(top); |
- } |
- |
- bool old_buffer_is_sorted() { return old_buffer_is_sorted_; } |
- bool old_buffer_is_filtered() { return old_buffer_is_filtered_; } |
- void EnsureSpace(intptr_t space_needed); |
- void Verify(); |
+ // This is used to add addresses to the store buffer non-concurrently. |
+ inline void Mark(Address addr); |
- bool PrepareForIteration(); |
+ // Slots that do not point to the ToSpace after callback invocation will be |
+ // removed from the set. |
+ void IteratePointersToNewSpace(ObjectSlotCallback callback); |
- void Filter(int flag); |
+ void Verify(); |
// Eliminates all stale store buffer entries from the store buffer, i.e., |
// slots that are not part of live objects anymore. This method must be |
@@ -95,124 +52,30 @@ class StoreBuffer { |
private: |
Heap* heap_; |
- // The store buffer is divided up into a new buffer that is constantly being |
- // filled by mutator activity and an old buffer that is filled with the data |
- // from the new buffer after compression. |
+ // The start and the limit of the buffer that contains store slots |
+ // added from the generated code. |
Address* start_; |
Address* limit_; |
- Address* old_start_; |
- Address* old_limit_; |
- Address* old_top_; |
- Address* old_reserved_limit_; |
- base::VirtualMemory* old_virtual_memory_; |
- |
- bool old_buffer_is_sorted_; |
- bool old_buffer_is_filtered_; |
- bool during_gc_; |
- // The garbage collector iterates over many pointers to new space that are not |
- // handled by the store buffer. This flag indicates whether the pointers |
- // found by the callbacks should be added to the store buffer or not. |
- bool store_buffer_rebuilding_enabled_; |
- StoreBufferCallback callback_; |
- bool may_move_store_buffer_entries_; |
- |
base::VirtualMemory* virtual_memory_; |
- // Two hash sets used for filtering. |
- // If address is in the hash set then it is guaranteed to be in the |
- // old part of the store buffer. |
- uintptr_t* hash_set_1_; |
- uintptr_t* hash_set_2_; |
- bool hash_sets_are_empty_; |
- |
// Used for synchronization of concurrent store buffer access. |
base::Mutex mutex_; |
- void ClearFilteringHashSets(); |
- |
- bool SpaceAvailable(intptr_t space_needed); |
- void ExemptPopularPages(int prime_sample_step, int threshold); |
+ void InsertEntriesFromBuffer(); |
- void ProcessOldToNewSlot(Address slot_address, |
- ObjectSlotCallback slot_callback); |
+ inline uint32_t AddressToSlotSetAndOffset(Address slot_address, |
+ SlotSet** slots); |
- void FindPointersToNewSpaceInRegion(Address start, Address end, |
- ObjectSlotCallback slot_callback); |
- |
- void IteratePointersInStoreBuffer(ObjectSlotCallback slot_callback); |
+ template <typename Callback> |
+ void Iterate(Callback callback); |
#ifdef VERIFY_HEAP |
void VerifyPointers(LargeObjectSpace* space); |
#endif |
- |
- friend class DontMoveStoreBufferEntriesScope; |
- friend class FindPointersToNewSpaceVisitor; |
- friend class StoreBufferRebuildScope; |
}; |
-class StoreBufferRebuilder { |
- public: |
- explicit StoreBufferRebuilder(StoreBuffer* store_buffer) |
- : store_buffer_(store_buffer) {} |
- |
- void Callback(MemoryChunk* page, StoreBufferEvent event); |
- |
- private: |
- StoreBuffer* store_buffer_; |
- |
- // We record in this variable how full the store buffer was when we started |
- // iterating over the current page, finding pointers to new space. If the |
- // store buffer overflows again we can exempt the page from the store buffer |
- // by rewinding to this point instead of having to search the store buffer. |
- Object*** start_of_current_page_; |
- // The current page we are scanning in the store buffer iterator. |
- MemoryChunk* current_page_; |
-}; |
- |
- |
-class StoreBufferRebuildScope { |
- public: |
- explicit StoreBufferRebuildScope(Heap* heap, StoreBuffer* store_buffer, |
- StoreBufferCallback callback) |
- : store_buffer_(store_buffer), |
- stored_state_(store_buffer->store_buffer_rebuilding_enabled_), |
- stored_callback_(store_buffer->callback_) { |
- store_buffer_->store_buffer_rebuilding_enabled_ = true; |
- store_buffer_->callback_ = callback; |
- (*callback)(heap, NULL, kStoreBufferStartScanningPagesEvent); |
- } |
- |
- ~StoreBufferRebuildScope() { |
- store_buffer_->callback_ = stored_callback_; |
- store_buffer_->store_buffer_rebuilding_enabled_ = stored_state_; |
- } |
- |
- private: |
- StoreBuffer* store_buffer_; |
- bool stored_state_; |
- StoreBufferCallback stored_callback_; |
-}; |
- |
- |
-class DontMoveStoreBufferEntriesScope { |
- public: |
- explicit DontMoveStoreBufferEntriesScope(StoreBuffer* store_buffer) |
- : store_buffer_(store_buffer), |
- stored_state_(store_buffer->may_move_store_buffer_entries_) { |
- store_buffer_->may_move_store_buffer_entries_ = false; |
- } |
- |
- ~DontMoveStoreBufferEntriesScope() { |
- store_buffer_->may_move_store_buffer_entries_ = stored_state_; |
- } |
- |
- private: |
- StoreBuffer* store_buffer_; |
- bool stored_state_; |
-}; |
- |
class LocalStoreBuffer BASE_EMBEDDED { |
public: |
LocalStoreBuffer() : top_(new Node(nullptr)) {} |