/* GIO - GLib Input, Output and Streaming Library

 * 

 * Copyright (C) 2006-2007 Red Hat, Inc.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General

 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.

 *

 * Author: Alexander Larsson <alexl@redhat.com>

 */

#include "config.h"

#include "gasynchelper.h"

/*< private >

 * SECTION:gasynchelper

 * @short_description: Asynchronous Helper Functions

 * @include: gio/gio.h

 * @see_also: #GAsyncResult

 * 

 * Provides helper functions for asynchronous operations.

 *

 **/

#ifdef G_OS_WIN32

gboolean

_g_win32_overlap_wait_result (HANDLE           hfile,

                              OVERLAPPED      *overlap,

                              DWORD           *transferred,

                              GCancellable    *cancellable)

{

  GPollFD pollfd[2];

  gboolean result = FALSE;

  gint num, npoll;

#if GLIB_SIZEOF_VOID_P == 8

  pollfd[0].fd = (gint64)overlap->hEvent;

#else

  pollfd[0].fd = (gint)overlap->hEvent;

#endif

  pollfd[0].events = G_IO_IN;

  num = 1;

  if (g_cancellable_make_pollfd (cancellable, &pollfd[1]))

    num++;

loop:

  npoll = g_poll (pollfd, num, -1);

  if (npoll <= 0)

    /* error out, should never happen */

    goto end;

  if (g_cancellable_is_cancelled (cancellable))

    {

      /* CancelIO only cancels pending operations issued by the

       * current thread and since we're doing only sync operations,

       * this is safe.... */

      /* CancelIoEx is only Vista+. Since we have only one overlap

       * operaton on this thread, we can just use: */

      result = CancelIo (hfile);

      g_warn_if_fail (result);

    }

  result = GetOverlappedResult (overlap->hEvent, overlap, transferred, FALSE);

  if (result == FALSE &&

      GetLastError () == ERROR_IO_INCOMPLETE &&

      !g_cancellable_is_cancelled (cancellable))

    goto loop;

end:

  if (num > 1)

    g_cancellable_release_fd (cancellable);

  return result;

}

#endif