RedFlag/server/cmd/server/service_windows.go

//go:build windows

package main

import (
	"context"
	"time"

	"golang.org/x/sys/windows/svc"
)

const serverServiceName = "RedFlagServer"

type windowsServerService struct {
	run func(context.Context, func())
}

func runWindowsService(run func(context.Context, func())) (bool, error) {
	service, err := svc.IsWindowsService()
	if err != nil || !service {
		return service, err
	}
	return true, svc.Run(serverServiceName, &windowsServerService{run: run})
}

func (s *windowsServerService) Execute(_ []string, requests <-chan svc.ChangeRequest, changes chan<- svc.Status) (bool, uint32) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	ready := make(chan struct{})
	done := make(chan struct{})
	status := svc.Status{State: svc.StartPending, CheckPoint: 1, WaitHint: 10000}
	changes <- status
	go func() {
		defer close(done)
		s.run(ctx, func() { close(ready) })
	}()

	ticker := time.NewTicker(2 * time.Second)
	defer ticker.Stop()
	for {
		select {
		case <-ready:
			ready = nil
			if ctx.Err() == nil {
				status = svc.Status{State: svc.Running, Accepts: svc.AcceptStop | svc.AcceptShutdown}
				changes <- status
			}
		case request := <-requests:
			switch request.Cmd {
			case svc.Interrogate:
				changes <- status
			case svc.Stop, svc.Shutdown:
				status = svc.Status{State: svc.StopPending, CheckPoint: 1, WaitHint: 10000}
				changes <- status
				cancel()
			}
		case <-ticker.C:
			if status.State == svc.StartPending || status.State == svc.StopPending {
				status.CheckPoint++
				changes <- status
			}
		case <-done:
			if ctx.Err() == nil {
				return true, 1 // An unsolicited exit is not a successful service stop.
			}
			return false, 0
		}
	}
}