intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 31 insertions, 0 deletions

diff --git a/contrib/libs/cxxsupp/libcxx/src/support/win32/atomic_win32.cpp b/contrib/libs/cxxsupp/libcxx/src/support/win32/atomic_win32.cpp
new file mode 100644
index 00000000000..28cb0722ce7
--- /dev/null
+++ b/contrib/libs/cxxsupp/libcxx/src/support/win32/atomic_win32.cpp
@@ -0,0 +1,31 @@
+#include <intrin.h>
+#include <cstdint>
+
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace {
+static const int __msvc_locks_size = 1024;
+volatile long __msvc_locks[__msvc_locks_size];
+
+size_t __msvc_lock_hash(void* __p) {
+    uintptr_t __num = reinterpret_cast<uintptr_t>(__p);
+    return (__num ^ (__num >> 10)) & (__msvc_locks_size - 1);
+}
+}
+
+void __msvc_lock(void* __p) {
+    volatile long& __lock = __msvc_locks[__msvc_lock_hash(__p)];
+    while (_InterlockedExchange(&__lock, 1) == 0) {
+#if defined(_M_ARM) || defined(_M_ARM64)
+        __yield();
+#endif
+    }
+}
+
+void __msvc_unlock(void* __p) {
+    volatile long& __lock = __msvc_locks[__msvc_lock_hash(__p)];
+    _InterlockedExchange(&__lock, 0);
+}
+
+_LIBCPP_END_NAMESPACE_STD
\ No newline at end of file