1 files changed, 25 insertions, 0 deletions
diff --git a/memory/build/Mutex.cpp b/memory/build/Mutex.cpp
new file mode 100644
index 0000000000..49f5d4e949
--- /dev/null
+++ b/memory/build/Mutex.cpp
@@ -0,0 +1,25 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Mutex.h"
+
+#if defined(XP_DARWIN)
+
+// static
+bool Mutex::SpinInKernelSpace() {
+#  ifdef __aarch64__
+  return true;
+#  else
+  if (__builtin_available(macOS 10.15, *)) {
+    return true;
+  }
+
+  return false;
+#  endif
+}
+
+// static
+const bool Mutex::gSpinInKernelSpace = SpinInKernelSpace();
+
+#endif  // defined(XP_DARWIN)