Implement Mutex in Synchronization

stdlib/public/Synchronization/Mutex/WindowsImpl.swift

@@ -0,0 +1,51 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Atomics open source project
+//
+// Copyright (c) 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import WinSDK.core.synch
+
+@available(SwiftStdlib 6.0, *)
+@frozen
+@usableFromInline
+@_staticExclusiveOnly
+internal struct _MutexHandle: ~Copyable {
+  @usableFromInline
+  let value: _Cell<SRWLOCK>
+
+  @available(SwiftStdlib 6.0, *)
+  @_alwaysEmitIntoClient
+  @_transparent
+  init() {
+    value = _Cell(SRWLOCK())
+  }
+
+  @available(SwiftStdlib 6.0, *)
+  @_alwaysEmitIntoClient
+  @_transparent
+  borrowing func lock() {
+    AcquireSRWLockExclusive(PSRWLOCK(value.rawAddress))
+  }
+
+  @available(SwiftStdlib 6.0, *)
+  @_alwaysEmitIntoClient
+  @_transparent
+  borrowing func tryLock() -> Bool {
+    // Windows BOOLEAN gets imported as 'UInt8'...
+    TryAcquireSRWLockExclusive(PSRWLOCK(value.rawAddress)) != 0
+  }
+
+  @available(SwiftStdlib 6.0, *)
+  @_alwaysEmitIntoClient
+  @_transparent
+  borrowing func unlock() {
+    ReleaseSRWLockExclusive(PSRWLOCK(value.rawAddress))
+  }
+}