inital commit

Overlord-Client/cmd/agent/mutex/mutex_windows.go

@@ -0,0 +1,38 @@
+//go:build windows
+
+package mutex
+
+import (
+	"fmt"
+
+	"golang.org/x/sys/windows"
+)
+
+func Acquire(name string) (func(), bool, error) {
+	if name == "" {
+		return func() {}, true, nil
+	}
+
+	sanitized, err := sanitizeName(name)
+	if err != nil {
+		return nil, false, err
+	}
+
+	fullName := "Global\\Overlord-" + sanitized
+	handle, err := windows.CreateMutex(nil, false, windows.StringToUTF16Ptr(fullName))
+	if err != nil {
+		return nil, false, fmt.Errorf("create mutex: %w", err)
+	}
+
+	if windows.GetLastError() == windows.ERROR_ALREADY_EXISTS {
+		windows.CloseHandle(handle)
+		return func() {}, false, nil
+	}
+
+	release := func() {
+		_ = windows.ReleaseMutex(handle)
+		_ = windows.CloseHandle(handle)
+	}
+
+	return release, true, nil
+}