Menghentikan Layanan

Program kontrol layanan dapat menghentikan layanan dengan menggunakan fungsi ControlService untuk mengirim permintaan SERVICE_CONTROL_STOP. Jika manajer kontrol layanan (SCM) menerima permintaan SERVICE_CONTROL_STOP untuk layanan, layanan akan dihentikan dengan meneruskan permintaan ke fungsi ServiceMain layanan. Namun, jika SCM menentukan bahwa layanan lain yang sedang berjalan tergantung pada layanan yang ditentukan, scmm tidak akan meneruskan permintaan berhenti. Sebaliknya, ia mengembalikan ERROR_DEPENDENT_SERVICES_RUNNING. Oleh karena itu, untuk menghentikan layanan tersebut secara terprogram, Anda harus terlebih dahulu menghitung dan menghentikan layanan dependennya.

Fungsi DoStopSvc dalam contoh berikut menunjukkan cara menghentikan layanan dan layanan dependen apa pun. Variabel szSvcName adalah variabel global yang berisi nama layanan yang akan dihentikan. Untuk contoh lengkap yang mengatur variabel ini, lihat 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;
}

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