--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/libuv/src/win/atomicops-inl.h	Wed Jan 14 19:39:52 2026 -0800
@@ -0,0 +1,61 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef UV_WIN_ATOMICOPS_INL_H_
+#define UV_WIN_ATOMICOPS_INL_H_
+
+#include "uv.h"
+#include "internal.h"
+
+
+/* Atomic set operation on char */
+#ifdef _MSC_VER /* MSVC */
+
+/* _InterlockedOr8 is supported by MSVC on x32 and x64. It is slightly less
+ * efficient than InterlockedExchange, but InterlockedExchange8 does not exist,
+ * and interlocked operations on larger targets might require the target to be
+ * aligned. */
+#pragma intrinsic(_InterlockedOr8)
+
+static char INLINE uv__atomic_exchange_set(char volatile* target) {
+  return _InterlockedOr8(target, 1);
+}
+
+#else /* GCC, Clang in mingw mode */
+
+static inline char uv__atomic_exchange_set(char volatile* target) {
+#if defined(__i386__) || defined(__x86_64__)
+  /* Mingw-32 version, hopefully this works for 64-bit gcc as well. */
+  const char one = 1;
+  char old_value;
+  __asm__ __volatile__ ("lock xchgb %0, %1\n\t"
+                        : "=r"(old_value), "=m"(*target)
+                        : "0"(one), "m"(*target)
+                        : "memory");
+  return old_value;
+#else
+  return __sync_fetch_and_or(target, 1);
+#endif
+}
+
+#endif
+
+#endif /* UV_WIN_ATOMICOPS_INL_H_ */