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/svc_test.go

@@ -0,0 +1,118 @@
+// 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 svc_test
+
+import (
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"golang.org/x/sys/windows/svc"
+	"golang.org/x/sys/windows/svc/mgr"
+)
+
+func getState(t *testing.T, s *mgr.Service) svc.State {
+	status, err := s.Query()
+	if err != nil {
+		t.Fatalf("Query(%s) failed: %s", s.Name, err)
+	}
+	return status.State
+}
+
+func testState(t *testing.T, s *mgr.Service, want svc.State) {
+	have := getState(t, s)
+	if have != want {
+		t.Fatalf("%s state is=%d want=%d", s.Name, have, want)
+	}
+}
+
+func waitState(t *testing.T, s *mgr.Service, want svc.State) {
+	for i := 0; ; i++ {
+		have := getState(t, s)
+		if have == want {
+			return
+		}
+		if i > 10 {
+			t.Fatalf("%s state is=%d, waiting timeout", s.Name, have)
+		}
+		time.Sleep(300 * time.Millisecond)
+	}
+}
+
+func TestExample(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode - it modifies system services")
+	}
+
+	const name = "myservice"
+
+	m, err := mgr.Connect()
+	if err != nil {
+		t.Fatalf("SCM connection failed: %s", err)
+	}
+	defer m.Disconnect()
+
+	dir, err := ioutil.TempDir("", "svc")
+	if err != nil {
+		t.Fatalf("failed to create temp directory: %v", err)
+	}
+	defer os.RemoveAll(dir)
+
+	exepath := filepath.Join(dir, "a.exe")
+	o, err := exec.Command("go", "build", "-o", exepath, "golang.org/x/sys/windows/svc/example").CombinedOutput()
+	if err != nil {
+		t.Fatalf("failed to build service program: %v\n%v", err, string(o))
+	}
+
+	s, err := m.OpenService(name)
+	if err == nil {
+		err = s.Delete()
+		if err != nil {
+			s.Close()
+			t.Fatalf("Delete failed: %s", err)
+		}
+		s.Close()
+	}
+	s, err = m.CreateService(name, exepath, mgr.Config{DisplayName: "my service"}, "is", "auto-started")
+	if err != nil {
+		t.Fatalf("CreateService(%s) failed: %v", name, err)
+	}
+	defer s.Close()
+
+	testState(t, s, svc.Stopped)
+	err = s.Start("is", "manual-started")
+	if err != nil {
+		t.Fatalf("Start(%s) failed: %s", s.Name, err)
+	}
+	waitState(t, s, svc.Running)
+	time.Sleep(1 * time.Second)
+
+	// testing deadlock from issues 4.
+	_, err = s.Control(svc.Interrogate)
+	if err != nil {
+		t.Fatalf("Control(%s) failed: %s", s.Name, err)
+	}
+	_, err = s.Control(svc.Interrogate)
+	if err != nil {
+		t.Fatalf("Control(%s) failed: %s", s.Name, err)
+	}
+	time.Sleep(1 * time.Second)
+
+	_, err = s.Control(svc.Stop)
+	if err != nil {
+		t.Fatalf("Control(%s) failed: %s", s.Name, err)
+	}
+	waitState(t, s, svc.Stopped)
+
+	err = s.Delete()
+	if err != nil {
+		t.Fatalf("Delete failed: %s", err)
+	}
+}