1 files changed, 60 insertions, 11 deletions

diff --git a/deps/v8/src/heap/store-buffer.cc b/deps/v8/src/heap/store-buffer.cc
index d73e3235c15..b428a82046c 100644
--- a/deps/v8/src/heap/store-buffer.cc
+++ b/deps/v8/src/heap/store-buffer.cc
@@ -10,6 +10,7 @@
 #include "src/base/template-utils.h"
 #include "src/counters.h"
 #include "src/heap/incremental-marking.h"
+#include "src/heap/store-buffer-inl.h"
 #include "src/isolate.h"
 #include "src/objects-inl.h"
 #include "src/v8.h"
@@ -30,22 +31,28 @@ StoreBuffer::StoreBuffer(Heap* heap)
 }
 
 void StoreBuffer::SetUp() {
-  // Allocate 3x the buffer size, so that we can start the new store buffer
-  // aligned to 2x the size.  This lets us use a bit test to detect the end of
-  // the area.
+  const size_t requested_size = kStoreBufferSize * kStoreBuffers;
+  // Allocate buffer memory aligned at least to kStoreBufferSize. This lets us
+  // use a bit test to detect the ends of the buffers.
+  const size_t alignment =
+      std::max<size_t>(kStoreBufferSize, AllocatePageSize());
+  void* hint = AlignedAddress(heap_->GetRandomMmapAddr(), alignment);
   VirtualMemory reservation;
-  if (!AllocVirtualMemory(kStoreBufferSize * 3, heap_->GetRandomMmapAddr(),
-                          &reservation)) {
+  if (!AlignedAllocVirtualMemory(requested_size, alignment, hint,
+                                 &reservation)) {
     heap_->FatalProcessOutOfMemory("StoreBuffer::SetUp");
   }
+
   Address start = reservation.address();
-  start_[0] = reinterpret_cast<Address*>(::RoundUp(start, kStoreBufferSize));
+  const size_t allocated_size = reservation.size();
+
+  start_[0] = reinterpret_cast<Address*>(start);
   limit_[0] = start_[0] + (kStoreBufferSize / kPointerSize);
   start_[1] = limit_[0];
   limit_[1] = start_[1] + (kStoreBufferSize / kPointerSize);
 
-  Address* vm_limit = reinterpret_cast<Address*>(start + reservation.size());
-
+  // Sanity check the buffers.
+  Address* vm_limit = reinterpret_cast<Address*>(start + allocated_size);
   USE(vm_limit);
   for (int i = 0; i < kStoreBuffers; i++) {
     DCHECK(reinterpret_cast<Address>(start_[i]) >= reservation.address());
@@ -55,8 +62,9 @@ void StoreBuffer::SetUp() {
     DCHECK_EQ(0, reinterpret_cast<Address>(limit_[i]) & kStoreBufferMask);
   }
 
-  if (!reservation.SetPermissions(reinterpret_cast<Address>(start_[0]),
-                                  kStoreBufferSize * kStoreBuffers,
+  // Set RW permissions only on the pages we use.
+  const size_t used_size = RoundUp(requested_size, CommitPageSize());
+  if (!reservation.SetPermissions(start, used_size,
                                   PageAllocator::kReadWrite)) {
     heap_->FatalProcessOutOfMemory("StoreBuffer::SetUp");
   }
@@ -65,7 +73,6 @@ void StoreBuffer::SetUp() {
   virtual_memory_.TakeControl(&reservation);
 }
 
-
 void StoreBuffer::TearDown() {
   if (virtual_memory_.IsReserved()) virtual_memory_.Free();
   top_ = nullptr;
@@ -76,6 +83,48 @@ void StoreBuffer::TearDown() {
   }
 }
 
+void StoreBuffer::DeleteDuringRuntime(StoreBuffer* store_buffer, Address start,
+                                      Address end) {
+  DCHECK(store_buffer->mode() == StoreBuffer::NOT_IN_GC);
+  store_buffer->InsertDeletionIntoStoreBuffer(start, end);
+}
+
+void StoreBuffer::InsertDuringRuntime(StoreBuffer* store_buffer, Address slot) {
+  DCHECK(store_buffer->mode() == StoreBuffer::NOT_IN_GC);
+  store_buffer->InsertIntoStoreBuffer(slot);
+}
+
+void StoreBuffer::DeleteDuringGarbageCollection(StoreBuffer* store_buffer,
+                                                Address start, Address end) {
+  // In GC the store buffer has to be empty at any time.
+  DCHECK(store_buffer->Empty());
+  DCHECK(store_buffer->mode() != StoreBuffer::NOT_IN_GC);
+  Page* page = Page::FromAddress(start);
+  if (end) {
+    RememberedSet<OLD_TO_NEW>::RemoveRange(page, start, end,
+                                           SlotSet::PREFREE_EMPTY_BUCKETS);
+  } else {
+    RememberedSet<OLD_TO_NEW>::Remove(page, start);
+  }
+}
+
+void StoreBuffer::InsertDuringGarbageCollection(StoreBuffer* store_buffer,
+                                                Address slot) {
+  DCHECK(store_buffer->mode() != StoreBuffer::NOT_IN_GC);
+  RememberedSet<OLD_TO_NEW>::Insert(Page::FromAddress(slot), slot);
+}
+
+void StoreBuffer::SetMode(StoreBufferMode mode) {
+  mode_ = mode;
+  if (mode == NOT_IN_GC) {
+    insertion_callback = &InsertDuringRuntime;
+    deletion_callback = &DeleteDuringRuntime;
+  } else {
+    insertion_callback = &InsertDuringGarbageCollection;
+    deletion_callback = &DeleteDuringGarbageCollection;
+  }
+}
+
 int StoreBuffer::StoreBufferOverflow(Isolate* isolate) {
   isolate->heap()->store_buffer()->FlipStoreBuffers();
   isolate->counters()->store_buffer_overflows()->Increment();