73c5c3b1_rol_Message_Constants___Manual_vice_Control_Message_Constants_Description
[Constant] WIN32_SERVICE_CONTROL_SHUTDOWN [Value] 0x00000005 [Description] 
Notifies a service that the system is shutting down so the service can perform cleanup tasks. If a service accepts this control code, it must stop after it performs its cleanup tasks. After the SCM sends this control code, it will not send other control codes to the service.
PHP: Win32Service Service Control Message Constants - Manual
Description