手把手教你实现Windows服务

struct ServiceContext
{
  ServiceContext() = delete;
  ServiceContext(std::string strSvcName) : m_strSvcName(strSvcName)
  {
    ;
  }
  ~ServiceContext()
  {
    if (m_hStartedEvent)
      CloseHandle(m_hStartedEvent);

    if (m_hStopEvent)
      CloseHandle(m_hStopEvent);
  }
  std::string           m_strSvcName;
  SERVICE_STATUS_HANDLE m_svcStatusHandle = nullptr; //Service Status Handle
  SERVICE_STATUS        m_svcStatus;                 //Service Name

  //This event used to check whether service worker is started
  HANDLE                m_hStartedEvent = CreateEvent(
    NULL,    // default security attributes
    TRUE,    // manual reset event
    FALSE,   // not signaled
    NULL);   // no name;   

  //This event used to notify service worker to stop
  HANDLE                m_hStopEvent = CreateEvent(
    NULL,    // default security attributes
    TRUE,    // manual reset event
    FALSE,   // not signaled
    NULL);   // no name;      
  DWORD                 m_dwHintTimeout = 5 * 1000;  // 5 seconds, check interval for starting and stopping
  DWORD                 m_dwCheckPoint = 1;          // It's used to co-work check for starting and stopping
};

ServiceContext gCoderSvcCtx("CoderService");

int main()
{
  SERVICE_TABLE_ENTRY svcTableEntry[] = {
    {const_cast<char *>(gCoderSvcCtx.m_strSvcName.c_str()), CoderServiceMain},
    {NULL, NULL}
  };

  //It should be invoked in main as soon as possible
  //Start failed, you can use GetLastError() to get the error code
  if (!StartServiceCtrlDispatcher(svcTableEntry))
    return -1;

  return 0;
}

//Refer to: https://docs.microsoft.com/en-us/windows/win32/services/writing-a-servicemain-function
bool ReportSvcStatus(ServiceContext& ctx,
  DWORD dwCurrentState,
  DWORD dwWin32ExitCode)
{
  // Fill in the SERVICE_STATUS structure.
  ctx.m_svcStatus.dwCurrentState = dwCurrentState;
  ctx.m_svcStatus.dwWin32ExitCode = dwWin32ExitCode;
  ctx.m_svcStatus.dwWaitHint = ctx.m_dwHintTimeout;

  if (dwCurrentState == SERVICE_START_PENDING)
    ctx.m_svcStatus.dwControlsAccepted = 0;
  else
    ctx.m_svcStatus.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;

  if ((dwCurrentState == SERVICE_RUNNING) ||
    (dwCurrentState == SERVICE_STOPPED))
    ctx.m_svcStatus.dwCheckPoint = 0;
  else 
    ctx.m_svcStatus.dwCheckPoint = ctx.m_dwCheckPoint++;

  // Report the status of the service to the SCM.
  return SetServiceStatus(ctx.m_svcStatusHandle, &ctx.m_svcStatus);
}

//Each Service binding a ServiceMain
void CoderServiceMain(DWORD dwNumServicesArgs, LPSTR *lpServiceArgVectors)
{
  // 1. Register Control Handler
  gCoderSvcCtx.m_svcStatusHandle = RegisterServiceCtrlHandler(const_cast<char *>(gCoderSvcCtx.m_strSvcName.c_str()),
    CoderServiceController);

  if (!gCoderSvcCtx.m_svcStatusHandle)
    return;

  // 2.  Set SERVICE_START_PENDING
  gCoderSvcCtx.m_svcStatus.dwServiceType = SERVICE_WIN32_OWN_PROCESS;
  gCoderSvcCtx.m_svcStatus.dwServiceSpecificExitCode = 0;

  if (!ReportSvcStatus(gCoderSvcCtx, SERVICE_START_PENDING, NO_ERROR))
  {
    ReportSvcStatus(gCoderSvcCtx, SERVICE_STOPPED, NO_ERROR);
    return;
  }

  // 3. your worker start
  // Service woker will work for specified task, if it return means it's stopped
  StartCoderServiceWorker(dwNumServicesArgs, lpServiceArgVectors);
  return;
}

class CoderWorker
{
public:
  bool Start()
{
    // You should fill your Worker thread init task here
    // Here just sleep 10 seconds to fake the init time
    std::this_thread::sleep_for(std::chrono::seconds(10));

    //Start the worker process tasks
    int iTmpPara = 1;
    m_thWorker = std::thread(&CoderWorker::Run, this, iTmpPara);

    return true;
  }
  void Stop()
{
    m_bStop = true;
    if (m_thWorker.joinable())
      m_thWorker.join();

    // Here we just Fake sleep 10 seconds to stop
    std::this_thread::sleep_for(std::chrono::seconds(10));
  }

  void Run(int iPara)
{
    while (!m_bStop)
    {
      //do task
      //Here just fill your code to do your work
      //just here fake sleep 1 second to do task
      std::this_thread::sleep_for(std::chrono::seconds(1));
    }
  }

private:
  std::thread   m_thWorker;
  volatile bool m_bStop = false;
};

// Here you can also specify other parameters
void CoderServiceWorker(ServiceContext& ctx, DWORD dwNumServicesArgs, LPSTR *lpServiceArgVectors)
{
  // 1. Init and Start worker and notify the it's started
  CoderWorker woker{};
  if (!woker.Start())
    ExitThread(-1);

  SetEvent(ctx.m_hStartedEvent);

  // 2. Wait for the stop event
  DWORD dwCode = WaitForSingleObject(ctx.m_hStopEvent, INFINITE);
  woker.Stop();
  ExitThread(0);
  return;
}

//Service Worker means what your service really do
void StartCoderServiceWorker(DWORD dwNumServicesArgs, LPSTR *lpServiceArgVectors)
{
  // 1. Start your service worker to handle tasks
  std::thread thWorker(CoderServiceWorker, std::ref(gCoderSvcCtx), dwNumServicesArgs, lpServiceArgVectors);
  
  // 2. Check the starting status
  while (true)
  {
    DWORD dwCode = WaitForSingleObject(gCoderSvcCtx.m_hStartedEvent, gCoderSvcCtx.m_dwHintTimeout);
    if (WAIT_TIMEOUT == dwCode)
    {
      //Still starting
      ReportSvcStatus(gCoderSvcCtx, SERVICE_START_PENDING, NO_ERROR);
    }
    else if (WAIT_OBJECT_0 == dwCode)
    {
      //Started Finish
      ResetEvent(gCoderSvcCtx.m_hStartedEvent);
      ReportSvcStatus(gCoderSvcCtx, SERVICE_RUNNING, NO_ERROR);
      break;
    }
    else
    {
      //Other errors
      ReportSvcStatus(gCoderSvcCtx, SERVICE_STOPPED, NO_ERROR);
      return;
    }
  }
  
  // 3. Check whether receive stop event
  while (true)
  {
    DWORD dwCheckTime = 1000; //1 second
    DWORD dwCode = WaitForSingleObject(gCoderSvcCtx.m_hStopEvent, dwCheckTime);
    if (WAIT_TIMEOUT == dwCode)
    {
      //Still runining
      continue;
    }
    else if (WAIT_OBJECT_0 == dwCode)
    {
      //It begin to stop
      // run into Stop pending status
      ReportSvcStatus(gCoderSvcCtx, SERVICE_STOP_PENDING, NO_ERROR);
      break;
    }
    else
    {
      //Other errors
      ReportSvcStatus(gCoderSvcCtx, SERVICE_STOPPED, NO_ERROR);
      return;
    }
  }

  // 4. Check the stopping status
  // If it's stopped then set the status to STOP
  HANDLE hThreadHandle = thWorker.native_handle();
  while (true)
  {
    DWORD dwCode = WaitForSingleObject(hThreadHandle, gCoderSvcCtx.m_dwHintTimeout);
    if (WAIT_TIMEOUT == dwCode)
    {
      //Still stopping
      ReportSvcStatus(gCoderSvcCtx, SERVICE_STOP_PENDING, NO_ERROR);
    }
    else if (WAIT_OBJECT_0 == dwCode)
    {
      // stop Finish
      // Reset the stop event
      ResetEvent(gCoderSvcCtx.m_hStopEvent);
      ReportSvcStatus(gCoderSvcCtx, SERVICE_STOPPED, NO_ERROR);
      break;
    }
    else
    {
      //Other errors
      ReportSvcStatus(gCoderSvcCtx, SERVICE_STOPPED, NO_ERROR);
      return;
    }
  }
  return;
}

//Each Service have a Service Controller to control the 
void CoderServiceController(DWORD dwControl)
{
  // Handle the requested control code. 
  switch (dwControl)
  {
  case SERVICE_CONTROL_SHUTDOWN:
  case SERVICE_CONTROL_STOP:
    ReportSvcStatus(gCoderSvcCtx, SERVICE_STOP_PENDING, NO_ERROR);
    // Signal the service to stop.
    SetEvent(gCoderSvcCtx.m_hStopEvent);

    return;

  default:
    break;
  }
}