service.go

Documentation: golang.org/x/sys/windows/svc/example

     1  // Copyright 2012 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build windows
     6  
     7  package main
     8  
     9  import (
    10  	"fmt"
    11  	"strings"
    12  	"time"
    13  
    14  	"golang.org/x/sys/windows/svc"
    15  	"golang.org/x/sys/windows/svc/debug"
    16  	"golang.org/x/sys/windows/svc/eventlog"
    17  )
    18  
    19  var elog debug.Log
    20  
    21  type exampleService struct{}
    22  
    23  func (m *exampleService) Execute(args []string, r <-chan svc.ChangeRequest, changes chan<- svc.Status) (ssec bool, errno uint32) {
    24  	const cmdsAccepted = svc.AcceptStop | svc.AcceptShutdown | svc.AcceptPauseAndContinue
    25  	changes <- svc.Status{State: svc.StartPending}
    26  	fasttick := time.Tick(500 * time.Millisecond)
    27  	slowtick := time.Tick(2 * time.Second)
    28  	tick := fasttick
    29  	changes <- svc.Status{State: svc.Running, Accepts: cmdsAccepted}
    30  loop:
    31  	for {
    32  		select {
    33  		case <-tick:
    34  			beep()
    35  			elog.Info(1, "beep")
    36  		case c := <-r:
    37  			switch c.Cmd {
    38  			case svc.Interrogate:
    39  				changes <- c.CurrentStatus
    40  				// Testing deadlock from https://code.google.com/p/winsvc/issues/detail?id=4
    41  				time.Sleep(100 * time.Millisecond)
    42  				changes <- c.CurrentStatus
    43  			case svc.Stop, svc.Shutdown:
    44  				// golang.org/x/sys/windows/svc.TestExample is verifying this output.
    45  				testOutput := strings.Join(args, "-")
    46  				testOutput += fmt.Sprintf("-%d", c.Context)
    47  				elog.Info(1, testOutput)
    48  				break loop
    49  			case svc.Pause:
    50  				changes <- svc.Status{State: svc.Paused, Accepts: cmdsAccepted}
    51  				tick = slowtick
    52  			case svc.Continue:
    53  				changes <- svc.Status{State: svc.Running, Accepts: cmdsAccepted}
    54  				tick = fasttick
    55  			default:
    56  				elog.Error(1, fmt.Sprintf("unexpected control request #%d", c))
    57  			}
    58  		}
    59  	}
    60  	changes <- svc.Status{State: svc.StopPending}
    61  	return
    62  }
    63  
    64  func runService(name string, isDebug bool) {
    65  	var err error
    66  	if isDebug {
    67  		elog = debug.New(name)
    68  	} else {
    69  		elog, err = eventlog.Open(name)
    70  		if err != nil {
    71  			return
    72  		}
    73  	}
    74  	defer elog.Close()
    75  
    76  	elog.Info(1, fmt.Sprintf("starting %s service", name))
    77  	run := svc.Run
    78  	if isDebug {
    79  		run = debug.Run
    80  	}
    81  	err = run(name, &exampleService{})
    82  	if err != nil {
    83  		elog.Error(1, fmt.Sprintf("%s service failed: %v", name, err))
    84  		return
    85  	}
    86  	elog.Info(1, fmt.Sprintf("%s service stopped", name))
    87  }
    88
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