--- /dev/null
+// 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 provides everything required to build Windows service.
+//
+package svc
+
+import (
+ "errors"
+ "runtime"
+ "syscall"
+ "unsafe"
+
+ "golang.org/x/sys/windows"
+)
+
+// State describes service execution state (Stopped, Running and so on).
+type State uint32
+
+const (
+ Stopped = State(windows.SERVICE_STOPPED)
+ StartPending = State(windows.SERVICE_START_PENDING)
+ StopPending = State(windows.SERVICE_STOP_PENDING)
+ Running = State(windows.SERVICE_RUNNING)
+ ContinuePending = State(windows.SERVICE_CONTINUE_PENDING)
+ PausePending = State(windows.SERVICE_PAUSE_PENDING)
+ Paused = State(windows.SERVICE_PAUSED)
+)
+
+// Cmd represents service state change request. It is sent to a service
+// by the service manager, and should be actioned upon by the service.
+type Cmd uint32
+
+const (
+ Stop = Cmd(windows.SERVICE_CONTROL_STOP)
+ Pause = Cmd(windows.SERVICE_CONTROL_PAUSE)
+ Continue = Cmd(windows.SERVICE_CONTROL_CONTINUE)
+ Interrogate = Cmd(windows.SERVICE_CONTROL_INTERROGATE)
+ Shutdown = Cmd(windows.SERVICE_CONTROL_SHUTDOWN)
+ ParamChange = Cmd(windows.SERVICE_CONTROL_PARAMCHANGE)
+ NetBindAdd = Cmd(windows.SERVICE_CONTROL_NETBINDADD)
+ NetBindRemove = Cmd(windows.SERVICE_CONTROL_NETBINDREMOVE)
+ NetBindEnable = Cmd(windows.SERVICE_CONTROL_NETBINDENABLE)
+ NetBindDisable = Cmd(windows.SERVICE_CONTROL_NETBINDDISABLE)
+ DeviceEvent = Cmd(windows.SERVICE_CONTROL_DEVICEEVENT)
+ HardwareProfileChange = Cmd(windows.SERVICE_CONTROL_HARDWAREPROFILECHANGE)
+ PowerEvent = Cmd(windows.SERVICE_CONTROL_POWEREVENT)
+ SessionChange = Cmd(windows.SERVICE_CONTROL_SESSIONCHANGE)
+)
+
+// Accepted is used to describe commands accepted by the service.
+// Note that Interrogate is always accepted.
+type Accepted uint32
+
+const (
+ AcceptStop = Accepted(windows.SERVICE_ACCEPT_STOP)
+ AcceptShutdown = Accepted(windows.SERVICE_ACCEPT_SHUTDOWN)
+ AcceptPauseAndContinue = Accepted(windows.SERVICE_ACCEPT_PAUSE_CONTINUE)
+ AcceptParamChange = Accepted(windows.SERVICE_ACCEPT_PARAMCHANGE)
+ AcceptNetBindChange = Accepted(windows.SERVICE_ACCEPT_NETBINDCHANGE)
+ AcceptHardwareProfileChange = Accepted(windows.SERVICE_ACCEPT_HARDWAREPROFILECHANGE)
+ AcceptPowerEvent = Accepted(windows.SERVICE_ACCEPT_POWEREVENT)
+ AcceptSessionChange = Accepted(windows.SERVICE_ACCEPT_SESSIONCHANGE)
+)
+
+// Status combines State and Accepted commands to fully describe running service.
+type Status struct {
+ State State
+ Accepts Accepted
+ CheckPoint uint32 // used to report progress during a lengthy operation
+ WaitHint uint32 // estimated time required for a pending operation, in milliseconds
+}
+
+// ChangeRequest is sent to the service Handler to request service status change.
+type ChangeRequest struct {
+ Cmd Cmd
+ EventType uint32
+ EventData uintptr
+ CurrentStatus Status
+}
+
+// Handler is the interface that must be implemented to build Windows service.
+type Handler interface {
+
+ // Execute will be called by the package code at the start of
+ // the service, and the service will exit once Execute completes.
+ // Inside Execute you must read service change requests from r and
+ // act accordingly. You must keep service control manager up to date
+ // about state of your service by writing into s as required.
+ // args contains service name followed by argument strings passed
+ // to the service.
+ // You can provide service exit code in exitCode return parameter,
+ // with 0 being "no error". You can also indicate if exit code,
+ // if any, is service specific or not by using svcSpecificEC
+ // parameter.
+ Execute(args []string, r <-chan ChangeRequest, s chan<- Status) (svcSpecificEC bool, exitCode uint32)
+}
+
+var (
+ // These are used by asm code.
+ goWaitsH uintptr
+ cWaitsH uintptr
+ ssHandle uintptr
+ sName *uint16
+ sArgc uintptr
+ sArgv **uint16
+ ctlHandlerExProc uintptr
+ cSetEvent uintptr
+ cWaitForSingleObject uintptr
+ cRegisterServiceCtrlHandlerExW uintptr
+)
+
+func init() {
+ k := syscall.MustLoadDLL("kernel32.dll")
+ cSetEvent = k.MustFindProc("SetEvent").Addr()
+ cWaitForSingleObject = k.MustFindProc("WaitForSingleObject").Addr()
+ a := syscall.MustLoadDLL("advapi32.dll")
+ cRegisterServiceCtrlHandlerExW = a.MustFindProc("RegisterServiceCtrlHandlerExW").Addr()
+}
+
+// The HandlerEx prototype also has a context pointer but since we don't use
+// it at start-up time we don't have to pass it over either.
+type ctlEvent struct {
+ cmd Cmd
+ eventType uint32
+ eventData uintptr
+ errno uint32
+}
+
+// service provides access to windows service api.
+type service struct {
+ name string
+ h windows.Handle
+ cWaits *event
+ goWaits *event
+ c chan ctlEvent
+ handler Handler
+}
+
+func newService(name string, handler Handler) (*service, error) {
+ var s service
+ var err error
+ s.name = name
+ s.c = make(chan ctlEvent)
+ s.handler = handler
+ s.cWaits, err = newEvent()
+ if err != nil {
+ return nil, err
+ }
+ s.goWaits, err = newEvent()
+ if err != nil {
+ s.cWaits.Close()
+ return nil, err
+ }
+ return &s, nil
+}
+
+func (s *service) close() error {
+ s.cWaits.Close()
+ s.goWaits.Close()
+ return nil
+}
+
+type exitCode struct {
+ isSvcSpecific bool
+ errno uint32
+}
+
+func (s *service) updateStatus(status *Status, ec *exitCode) error {
+ if s.h == 0 {
+ return errors.New("updateStatus with no service status handle")
+ }
+ var t windows.SERVICE_STATUS
+ t.ServiceType = windows.SERVICE_WIN32_OWN_PROCESS
+ t.CurrentState = uint32(status.State)
+ if status.Accepts&AcceptStop != 0 {
+ t.ControlsAccepted |= windows.SERVICE_ACCEPT_STOP
+ }
+ if status.Accepts&AcceptShutdown != 0 {
+ t.ControlsAccepted |= windows.SERVICE_ACCEPT_SHUTDOWN
+ }
+ if status.Accepts&AcceptPauseAndContinue != 0 {
+ t.ControlsAccepted |= windows.SERVICE_ACCEPT_PAUSE_CONTINUE
+ }
+ if status.Accepts&AcceptParamChange != 0 {
+ t.ControlsAccepted |= windows.SERVICE_ACCEPT_PARAMCHANGE
+ }
+ if status.Accepts&AcceptNetBindChange != 0 {
+ t.ControlsAccepted |= windows.SERVICE_ACCEPT_NETBINDCHANGE
+ }
+ if status.Accepts&AcceptHardwareProfileChange != 0 {
+ t.ControlsAccepted |= windows.SERVICE_ACCEPT_HARDWAREPROFILECHANGE
+ }
+ if status.Accepts&AcceptPowerEvent != 0 {
+ t.ControlsAccepted |= windows.SERVICE_ACCEPT_POWEREVENT
+ }
+ if status.Accepts&AcceptSessionChange != 0 {
+ t.ControlsAccepted |= windows.SERVICE_ACCEPT_SESSIONCHANGE
+ }
+ if ec.errno == 0 {
+ t.Win32ExitCode = windows.NO_ERROR
+ t.ServiceSpecificExitCode = windows.NO_ERROR
+ } else if ec.isSvcSpecific {
+ t.Win32ExitCode = uint32(windows.ERROR_SERVICE_SPECIFIC_ERROR)
+ t.ServiceSpecificExitCode = ec.errno
+ } else {
+ t.Win32ExitCode = ec.errno
+ t.ServiceSpecificExitCode = windows.NO_ERROR
+ }
+ t.CheckPoint = status.CheckPoint
+ t.WaitHint = status.WaitHint
+ return windows.SetServiceStatus(s.h, &t)
+}
+
+const (
+ sysErrSetServiceStatusFailed = uint32(syscall.APPLICATION_ERROR) + iota
+ sysErrNewThreadInCallback
+)
+
+func (s *service) run() {
+ s.goWaits.Wait()
+ s.h = windows.Handle(ssHandle)
+ argv := (*[100]*int16)(unsafe.Pointer(sArgv))[:sArgc]
+ args := make([]string, len(argv))
+ for i, a := range argv {
+ args[i] = syscall.UTF16ToString((*[1 << 20]uint16)(unsafe.Pointer(a))[:])
+ }
+
+ cmdsToHandler := make(chan ChangeRequest)
+ changesFromHandler := make(chan Status)
+ exitFromHandler := make(chan exitCode)
+
+ go func() {
+ ss, errno := s.handler.Execute(args, cmdsToHandler, changesFromHandler)
+ exitFromHandler <- exitCode{ss, errno}
+ }()
+
+ status := Status{State: Stopped}
+ ec := exitCode{isSvcSpecific: true, errno: 0}
+ var outch chan ChangeRequest
+ inch := s.c
+ var cmd Cmd
+ var evtype uint32
+ var evdata uintptr
+loop:
+ for {
+ select {
+ case r := <-inch:
+ if r.errno != 0 {
+ ec.errno = r.errno
+ break loop
+ }
+ inch = nil
+ outch = cmdsToHandler
+ cmd = r.cmd
+ evtype = r.eventType
+ evdata = r.eventData
+ case outch <- ChangeRequest{cmd, evtype, evdata, status}:
+ inch = s.c
+ outch = nil
+ case c := <-changesFromHandler:
+ err := s.updateStatus(&c, &ec)
+ if err != nil {
+ // best suitable error number
+ ec.errno = sysErrSetServiceStatusFailed
+ if err2, ok := err.(syscall.Errno); ok {
+ ec.errno = uint32(err2)
+ }
+ break loop
+ }
+ status = c
+ case ec = <-exitFromHandler:
+ break loop
+ }
+ }
+
+ s.updateStatus(&Status{State: Stopped}, &ec)
+ s.cWaits.Set()
+}
+
+func newCallback(fn interface{}) (cb uintptr, err error) {
+ defer func() {
+ r := recover()
+ if r == nil {
+ return
+ }
+ cb = 0
+ switch v := r.(type) {
+ case string:
+ err = errors.New(v)
+ case error:
+ err = v
+ default:
+ err = errors.New("unexpected panic in syscall.NewCallback")
+ }
+ }()
+ return syscall.NewCallback(fn), nil
+}
+
+// BUG(brainman): There is no mechanism to run multiple services
+// inside one single executable. Perhaps, it can be overcome by
+// using RegisterServiceCtrlHandlerEx Windows api.
+
+// Run executes service name by calling appropriate handler function.
+func Run(name string, handler Handler) error {
+ runtime.LockOSThread()
+
+ tid := windows.GetCurrentThreadId()
+
+ s, err := newService(name, handler)
+ if err != nil {
+ return err
+ }
+
+ ctlHandler := func(ctl uint32, evtype uint32, evdata uintptr, context uintptr) uintptr {
+ e := ctlEvent{cmd: Cmd(ctl), eventType: evtype, eventData: evdata}
+ // We assume that this callback function is running on
+ // the same thread as Run. Nowhere in MS documentation
+ // I could find statement to guarantee that. So putting
+ // check here to verify, otherwise things will go bad
+ // quickly, if ignored.
+ i := windows.GetCurrentThreadId()
+ if i != tid {
+ e.errno = sysErrNewThreadInCallback
+ }
+ s.c <- e
+ // Always return NO_ERROR (0) for now.
+ return 0
+ }
+
+ var svcmain uintptr
+ getServiceMain(&svcmain)
+ t := []windows.SERVICE_TABLE_ENTRY{
+ {syscall.StringToUTF16Ptr(s.name), svcmain},
+ {nil, 0},
+ }
+
+ goWaitsH = uintptr(s.goWaits.h)
+ cWaitsH = uintptr(s.cWaits.h)
+ sName = t[0].ServiceName
+ ctlHandlerExProc, err = newCallback(ctlHandler)
+ if err != nil {
+ return err
+ }
+
+ go s.run()
+
+ err = windows.StartServiceCtrlDispatcher(&t[0])
+ if err != nil {
+ return err
+ }
+ return nil
+}
+
+// StatusHandle returns service status handle. It is safe to call this function
+// from inside the Handler.Execute because then it is guaranteed to be set.
+// This code will have to change once multiple services are possible per process.
+func StatusHandle() windows.Handle {
+ return windows.Handle(ssHandle)
+}
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