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Arrêt d’un service

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Un programme de contrôle de service peut arrêter un service à l’aide de la fonction ControlService pour envoyer une demande de SERVICE_CONTROL_STOP. Si le gestionnaire de contrôle de service (SCM) reçoit une demande de SERVICE_CONTROL_STOP pour un service, il indique au service de s’arrêter en transférant la demande à la fonction ServiceMain du service. Toutefois, si le SCM détermine que d’autres services en cours d’exécution dépendent du service spécifié, il ne transfère pas la demande d’arrêt. Au lieu de cela, elle retourne ERROR_DEPENDENT_SERVICES_RUNNING. Par conséquent, pour arrêter par programmation un tel service, vous devez d’abord énumérer et arrêter ses services dépendants.

La fonction DoStopSvc dans l’exemple suivant montre comment arrêter un service et tous les services dépendants. La variable szSvcName est une variable globale qui contient le nom du service à arrêter. Pour obtenir l’exemple complet qui définit cette variable, consultez SvcControl.cpp.

//
// Purpose: 
//   Stops the service.
//
// Parameters:
//   None
// 
// Return value:
//   None
//
VOID __stdcall DoStopSvc()
{
    SERVICE_STATUS_PROCESS ssp;
    DWORD dwStartTime = GetTickCount();
    DWORD dwBytesNeeded;
    DWORD dwTimeout = 30000; // 30-second time-out
    DWORD dwWaitTime;

    // Get a handle to the SCM database. 
 
    schSCManager = OpenSCManager( 
        NULL,                    // local computer
        NULL,                    // ServicesActive database 
        SC_MANAGER_ALL_ACCESS);  // full access rights 
 
    if (NULL == schSCManager) 
    {
        printf("OpenSCManager failed (%d)\n", GetLastError());
        return;
    }

    // Get a handle to the service.

    schService = OpenService( 
        schSCManager,         // SCM database 
        szSvcName,            // name of service 
        SERVICE_STOP | 
        SERVICE_QUERY_STATUS | 
        SERVICE_ENUMERATE_DEPENDENTS);  
 
    if (schService == NULL)
    { 
        printf("OpenService failed (%d)\n", GetLastError()); 
        CloseServiceHandle(schSCManager);
        return;
    }    

    // Make sure the service is not already stopped.

    if ( !QueryServiceStatusEx( 
            schService, 
            SC_STATUS_PROCESS_INFO,
            (LPBYTE)&ssp, 
            sizeof(SERVICE_STATUS_PROCESS),
            &dwBytesNeeded ) )
    {
        printf("QueryServiceStatusEx failed (%d)\n", GetLastError()); 
        goto stop_cleanup;
    }

    if ( ssp.dwCurrentState == SERVICE_STOPPED )
    {
        printf("Service is already stopped.\n");
        goto stop_cleanup;
    }

    // If a stop is pending, wait for it.

    while ( ssp.dwCurrentState == SERVICE_STOP_PENDING ) 
    {
        printf("Service stop pending...\n");

        // Do not wait longer than the wait hint. A good interval is 
        // one-tenth of the wait hint but not less than 1 second  
        // and not more than 10 seconds. 
 
        dwWaitTime = ssp.dwWaitHint / 10;

        if( dwWaitTime < 1000 )
            dwWaitTime = 1000;
        else if ( dwWaitTime > 10000 )
            dwWaitTime = 10000;

        Sleep( dwWaitTime );

        if ( !QueryServiceStatusEx( 
                 schService, 
                 SC_STATUS_PROCESS_INFO,
                 (LPBYTE)&ssp, 
                 sizeof(SERVICE_STATUS_PROCESS),
                 &dwBytesNeeded ) )
        {
            printf("QueryServiceStatusEx failed (%d)\n", GetLastError()); 
            goto stop_cleanup;
        }

        if ( ssp.dwCurrentState == SERVICE_STOPPED )
        {
            printf("Service stopped successfully.\n");
            goto stop_cleanup;
        }

        if ( GetTickCount() - dwStartTime > dwTimeout )
        {
            printf("Service stop timed out.\n");
            goto stop_cleanup;
        }
    }

    // If the service is running, dependencies must be stopped first.

    StopDependentServices();

    // Send a stop code to the service.

    if ( !ControlService( 
            schService, 
            SERVICE_CONTROL_STOP, 
            (LPSERVICE_STATUS) &ssp ) )
    {
        printf( "ControlService failed (%d)\n", GetLastError() );
        goto stop_cleanup;
    }

    // Wait for the service to stop.

    while ( ssp.dwCurrentState != SERVICE_STOPPED ) 
    {
        Sleep( ssp.dwWaitHint );
        if ( !QueryServiceStatusEx( 
                schService, 
                SC_STATUS_PROCESS_INFO,
                (LPBYTE)&ssp, 
                sizeof(SERVICE_STATUS_PROCESS),
                &dwBytesNeeded ) )
        {
            printf( "QueryServiceStatusEx failed (%d)\n", GetLastError() );
            goto stop_cleanup;
        }

        if ( ssp.dwCurrentState == SERVICE_STOPPED )
            break;

        if ( GetTickCount() - dwStartTime > dwTimeout )
        {
            printf( "Wait timed out\n" );
            goto stop_cleanup;
        }
    }
    printf("Service stopped successfully\n");

stop_cleanup:
    CloseServiceHandle(schService); 
    CloseServiceHandle(schSCManager);
}

BOOL __stdcall StopDependentServices()
{
    DWORD i;
    DWORD dwBytesNeeded;
    DWORD dwCount;

    LPENUM_SERVICE_STATUS   lpDependencies = NULL;
    ENUM_SERVICE_STATUS     ess;
    SC_HANDLE               hDepService;
    SERVICE_STATUS_PROCESS  ssp;

    DWORD dwStartTime = GetTickCount();
    DWORD dwTimeout = 30000; // 30-second time-out

    // Pass a zero-length buffer to get the required buffer size.
    if ( EnumDependentServices( schService, SERVICE_ACTIVE, 
         lpDependencies, 0, &dwBytesNeeded, &dwCount ) ) 
    {
         // If the Enum call succeeds, then there are no dependent
         // services, so do nothing.
         return TRUE;
    } 
    else 
    {
        if ( GetLastError() != ERROR_MORE_DATA )
            return FALSE; // Unexpected error

        // Allocate a buffer for the dependencies.
        lpDependencies = (LPENUM_SERVICE_STATUS) HeapAlloc( 
            GetProcessHeap(), HEAP_ZERO_MEMORY, dwBytesNeeded );
  
        if ( !lpDependencies )
            return FALSE;

        __try {
            // Enumerate the dependencies.
            if ( !EnumDependentServices( schService, SERVICE_ACTIVE, 
                lpDependencies, dwBytesNeeded, &dwBytesNeeded,
                &dwCount ) )
            return FALSE;

            for ( i = 0; i < dwCount; i++ ) 
            {
                ess = *(lpDependencies + i);
                // Open the service.
                hDepService = OpenService( schSCManager, 
                   ess.lpServiceName, 
                   SERVICE_STOP | SERVICE_QUERY_STATUS );

                if ( !hDepService )
                   return FALSE;

                __try {
                    // Send a stop code.
                    if ( !ControlService( hDepService, 
                            SERVICE_CONTROL_STOP,
                            (LPSERVICE_STATUS) &ssp ) )
                    return FALSE;

                    // Wait for the service to stop.
                    while ( ssp.dwCurrentState != SERVICE_STOPPED ) 
                    {
                        Sleep( ssp.dwWaitHint );
                        if ( !QueryServiceStatusEx( 
                                hDepService, 
                                SC_STATUS_PROCESS_INFO,
                                (LPBYTE)&ssp, 
                                sizeof(SERVICE_STATUS_PROCESS),
                                &dwBytesNeeded ) )
                        return FALSE;

                        if ( ssp.dwCurrentState == SERVICE_STOPPED )
                            break;

                        if ( GetTickCount() - dwStartTime > dwTimeout )
                            return FALSE;
                    }
                } 
                __finally 
                {
                    // Always release the service handle.
                    CloseServiceHandle( hDepService );
                }
            }
        } 
        __finally 
        {
            // Always free the enumeration buffer.
            HeapFree( GetProcessHeap(), 0, lpDependencies );
        }
    } 
    return TRUE;
}

L’exemple de service complet