windows/svc: add new package to help create and manage Windows services

Change-Id: I58bb446aaa387b31d8a9ff4217793a170b96a7e2
Reviewed-on: https://go-review.googlesource.com/9104
Reviewed-by: Rob Pike <r@golang.org>

windows/svc/debug/service.go

@@ -0,0 +1,45 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build windows
+
+// Package debug provides facilities to execute svc.Handler on console.
+//
+package debug
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+
+	"golang.org/x/sys/windows/svc"
+)
+
+// Run executes service name by calling appropriate handler function.
+// The process is running on console, unlike real service. Use Ctrl+C to
+// send "Stop" command to your service.
+func Run(name string, handler svc.Handler) error {
+	cmds := make(chan svc.ChangeRequest)
+	changes := make(chan svc.Status)
+
+	sig := make(chan os.Signal)
+	signal.Notify(sig)
+
+	go func() {
+		status := svc.Status{State: svc.Stopped}
+		for {
+			select {
+			case <-sig:
+				cmds <- svc.ChangeRequest{svc.Stop, status}
+			case status = <-changes:
+			}
+		}
+	}()
+
+	_, errno := handler.Execute([]string{name}, cmds, changes)
+	if errno != 0 {
+		return syscall.Errno(errno)
+	}
+	return nil
+}