1 files changed, 36 insertions, 0 deletions
diff --git a/chromium/v8/src/heap/cppgc/caged-heap-local-data.cc b/chromium/v8/src/heap/cppgc/caged-heap-local-data.cc
new file mode 100644
index 00000000000..55ededdc087
--- /dev/null
+++ b/chromium/v8/src/heap/cppgc/caged-heap-local-data.cc
@@ -0,0 +1,36 @@
+// Copyright 2020 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 "include/cppgc/internal/caged-heap-local-data.h"
+
+#include <algorithm>
+#include <type_traits>
+
+#include "include/cppgc/platform.h"
+#include "src/base/macros.h"
+
+namespace cppgc {
+namespace internal {
+
+#if defined(CPPGC_YOUNG_GENERATION)
+
+static_assert(
+    std::is_trivially_default_constructible<AgeTable>::value,
+    "To support lazy committing, AgeTable must be trivially constructible");
+
+void AgeTable::Reset(PageAllocator* allocator) {
+  // TODO(chromium:1029379): Consider MADV_DONTNEED instead of MADV_FREE on
+  // POSIX platforms.
+  std::fill(table_.begin(), table_.end(), Age::kOld);
+  const uintptr_t begin = RoundUp(reinterpret_cast<uintptr_t>(table_.begin()),
+                                  allocator->CommitPageSize());
+  const uintptr_t end = RoundDown(reinterpret_cast<uintptr_t>(table_.end()),
+                                  allocator->CommitPageSize());
+  allocator->DiscardSystemPages(reinterpret_cast<void*>(begin), end - begin);
+}
+
+#endif
+
+}  // namespace internal
+}  // namespace cppgc