fix comments and callback type

cmd/agent/subcommands/run/command_windows.go

@@ -207,6 +207,14 @@ func StartAgentWithDefaults(ctxChan <-chan context.Context) (<-chan error, error
 	return errChan, nil
 }
 
+// Re-register the ctrl handler because Go uses SetConsoleCtrlHandler and Python uses posix signal calls.
+// This is only needed when using the embedded Python module.
+// When Python imports the signal module, it overrides the ctrl handler set by Go and installs the Windows posix signal handler.
+// Linux uses the POSIX signal handler for both Go and Python, so this is not an issue on Linux.
+// As Python checks if the signal handler is not the default handler before overwritting it.
+// If CPython adds a way to avoid overriding the ctrl handler, we can remove this workaround.
+// If Go adds support to use the posix signal handler on Windows, we can remove this workaround.
+// All calls to signal.Notify will no longer work after the Python module is started.
 func reRegisterCtrlHandler(log log.Component, _ collector.Component) {
 	log.Info("Re-registering Ctrl+C handler")
 	err := winutil.SetConsoleCtrlHandler(func(ctrlType uint32) bool {

pkg/util/winutil/winctrlhandler.go

@@ -8,16 +8,18 @@
 // Package winutil contains Windows OS utilities
 package winutil
 
-import "syscall"
+import "golang.org/x/sys/windows"
 
 var (
 	setConsoleCtrlHandler = k32.NewProc("SetConsoleCtrlHandler")
 )
 
+// Console control signal constants
+//
+// https://learn.microsoft.com/en-us/windows/console/handlerroutine
+
 const (
-	// CtrlCEvent is code for Cntrl+C event
-	CtrlCEvent = 0
-	// CtrlBreakEvent is code for Cntrl+Break event
+	CtrlCEvent     = 0
 	CtrlBreakEvent = 1
 )
 
@@ -29,9 +31,11 @@ func boolToInt(b bool) int {
 }
 
 // SetConsoleCtrlHandler sets the handler function for console control events.
+//
+// https://learn.microsoft.com/en-us/windows/console/setconsolectrlhandler
 func SetConsoleCtrlHandler(handler func(uint32) bool, add bool) error {
 	ret, _, err := setConsoleCtrlHandler.Call(
-		uintptr(syscall.NewCallbackCDecl(func(sig uint32) uintptr {
+		uintptr(windows.NewCallback(func(sig uint32) uintptr {
 			if handler(sig) {
 				return 1
 			}