[heap] Extract marking deque to separate file.

src/heap/sequential-marking-deque.cc

+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/sequential-marking-deque.h"
+
+#include "src/allocation.h"
+#include "src/base/bits.h"
+#include "src/heap/heap-inl.h"
+#include "src/heap/heap.h"
+
+namespace v8 {
+namespace internal {
+
+void SequentialMarkingDeque::SetUp() {
+  backing_store_ = new base::VirtualMemory(kMaxSize);
+  backing_store_committed_size_ = 0;
+  if (backing_store_ == nullptr) {
+    V8::FatalProcessOutOfMemory("SequentialMarkingDeque::SetUp");
+  }
+}
+
+void SequentialMarkingDeque::TearDown() { delete backing_store_; }
+
+void SequentialMarkingDeque::StartUsing() {
+  base::LockGuard<base::Mutex> guard(&mutex_);
+  if (in_use_) {
+    // This can happen in mark-compact GC if the incremental marker already
+    // started using the marking deque.
+    return;
+  }
+  in_use_ = true;
+  EnsureCommitted();
+  array_ = reinterpret_cast<HeapObject**>(backing_store_->address());
+  size_t size = FLAG_force_marking_deque_overflows
+                    ? 64 * kPointerSize
+                    : backing_store_committed_size_;
+  DCHECK(
+      base::bits::IsPowerOfTwo32(static_cast<uint32_t>(size / kPointerSize)));
+  mask_ = static_cast<int>((size / kPointerSize) - 1);
+  top_ = bottom_ = 0;
+  overflowed_ = false;
+}
+
+void SequentialMarkingDeque::StopUsing() {
+  base::LockGuard<base::Mutex> guard(&mutex_);
+  if (!in_use_) return;
+  DCHECK(IsEmpty());
+  DCHECK(!overflowed_);
+  top_ = bottom_ = mask_ = 0;
+  in_use_ = false;
+  if (FLAG_concurrent_sweeping) {
+    StartUncommitTask();
+  } else {
+    Uncommit();
+  }
+}
+
+void SequentialMarkingDeque::Clear() {
+  DCHECK(in_use_);
+  top_ = bottom_ = 0;
+  overflowed_ = false;
+}
+
+void SequentialMarkingDeque::Uncommit() {
+  DCHECK(!in_use_);
+  bool success = backing_store_->Uncommit(backing_store_->address(),
+                                          backing_store_committed_size_);
+  backing_store_committed_size_ = 0;
+  CHECK(success);
+}
+
+void SequentialMarkingDeque::EnsureCommitted() {
+  DCHECK(in_use_);
+  if (backing_store_committed_size_ > 0) return;
+
+  for (size_t size = kMaxSize; size >= kMinSize; size /= 2) {
+    if (backing_store_->Commit(backing_store_->address(), size, false)) {
+      backing_store_committed_size_ = size;
+      break;
+    }
+  }
+  if (backing_store_committed_size_ == 0) {
+    V8::FatalProcessOutOfMemory("SequentialMarkingDeque::EnsureCommitted");
+  }
+}
+
+void SequentialMarkingDeque::StartUncommitTask() {
+  if (!uncommit_task_pending_) {
+    uncommit_task_pending_ = true;
+    UncommitTask* task = new UncommitTask(heap_->isolate(), this);
+    V8::GetCurrentPlatform()->CallOnBackgroundThread(
+        task, v8::Platform::kShortRunningTask);
+  }
+}
+
+}  // namespace internal
+}  // namespace v8