Add Graceful shutdown for Windows and hooks for shutdown of goroutines (#8964)

* Graceful Shutdown for windows and others

Restructures modules/graceful, adding shutdown for windows, removing and
replacing the old minwinsvc code.

Creates a new waitGroup - terminate which allows for goroutines to
finish up after the shutdown of the servers.

Shutdown and terminate hooks are added for goroutines.

* Remove unused functions - these can be added in a different PR

* Add startup timeout functionality

* Document STARTUP_TIMEOUT

vendor/golang.org/x/sys/windows/svc/debug/log.go

@@ -0,0 +1,56 @@
+// 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
+
+import (
+	"os"
+	"strconv"
+)
+
+// Log interface allows different log implementations to be used.
+type Log interface {
+	Close() error
+	Info(eid uint32, msg string) error
+	Warning(eid uint32, msg string) error
+	Error(eid uint32, msg string) error
+}
+
+// ConsoleLog provides access to the console.
+type ConsoleLog struct {
+	Name string
+}
+
+// New creates new ConsoleLog.
+func New(source string) *ConsoleLog {
+	return &ConsoleLog{Name: source}
+}
+
+// Close closes console log l.
+func (l *ConsoleLog) Close() error {
+	return nil
+}
+
+func (l *ConsoleLog) report(kind string, eid uint32, msg string) error {
+	s := l.Name + "." + kind + "(" + strconv.Itoa(int(eid)) + "): " + msg + "\n"
+	_, err := os.Stdout.Write([]byte(s))
+	return err
+}
+
+// Info writes an information event msg with event id eid to the console l.
+func (l *ConsoleLog) Info(eid uint32, msg string) error {
+	return l.report("info", eid, msg)
+}
+
+// Warning writes an warning event msg with event id eid to the console l.
+func (l *ConsoleLog) Warning(eid uint32, msg string) error {
+	return l.report("warn", eid, msg)
+}
+
+// Error writes an error event msg with event id eid to the console l.
+func (l *ConsoleLog) Error(eid uint32, msg string) error {
+	return l.report("error", eid, msg)
+}

vendor/golang.org/x/sys/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{Cmd: svc.Stop, CurrentStatus: status}
+			case status = <-changes:
+			}
+		}
+	}()
+
+	_, errno := handler.Execute([]string{name}, cmds, changes)
+	if errno != 0 {
+		return syscall.Errno(errno)
+	}
+	return nil
+}