Gracefully terminate a process on Windows

Question

I'm writing a server application in Go, and using a wrapper to run it as a Windows service.

There's a need to gracefully shut down the server (to close resources and connections properly), and in UNIX it would be handled through the SIGTERM signal. No big deal.

Though on Windows things seem very different. I see on this guide that signals actually exist on windows (?), and the SIGTERM is defined, though other pages indicate they don't, or to use other mechanisms like WM_CLOSE.

What is the preferable way to tell a headless process to gracefully terminate? How should it be implemented in Go?

The server is designed to be multiplatform, so the most standard way of doing it is preferable.

Answer 1

Signaling is implemented on Windows but Unix signals are unavailable. There is an example in the signal package of golang for Windows to send a Ctrl-Break. It is refactored for interactive use here.

Answer 2

The idea of using *nix constructs and functions to Windows is generally bad and prone to weird tricks that may or may not work.

The proper way to cleanup on shutdown a GUI application is the handling of WM_QUERYENDSESSION and WM_ENDSESSION. Also, you have flexibility on generic shut-down mechanism, check here.

The proper way to get notified if you are a service is the service handler of your console application (SERVICE_STOPPED). For more, see Writing a ServiceMain.