1 /* GIO - GLib Input, Output and Streaming Library
2 *
3 * Copyright (C) 2006-2007 Red Hat, Inc.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General
16 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
17 *
18 * Author: Alexander Larsson <alexl@redhat.com>
19 */
20
21 #include "config.h"
22
23 #include "gasynchelper.h"
24
25
26 /*< private >
27 * SECTION:gasynchelper
28 * @short_description: Asynchronous Helper Functions
29 * @include: gio/gio.h
30 * @see_also: #GAsyncResult
31 *
32 * Provides helper functions for asynchronous operations.
33 *
34 **/
35
36 #ifdef G_OS_WIN32
37 gboolean
_g_win32_overlap_wait_result(HANDLE hfile,OVERLAPPED * overlap,DWORD * transferred,GCancellable * cancellable)38 _g_win32_overlap_wait_result (HANDLE hfile,
39 OVERLAPPED *overlap,
40 DWORD *transferred,
41 GCancellable *cancellable)
42 {
43 GPollFD pollfd[2];
44 gboolean result = FALSE;
45 gint num, npoll;
46
47 #if GLIB_SIZEOF_VOID_P == 8
48 pollfd[0].fd = (gint64)overlap->hEvent;
49 #else
50 pollfd[0].fd = (gint)overlap->hEvent;
51 #endif
52 pollfd[0].events = G_IO_IN;
53 num = 1;
54
55 if (g_cancellable_make_pollfd (cancellable, &pollfd[1]))
56 num++;
57
58 loop:
59 npoll = g_poll (pollfd, num, -1);
60 if (npoll <= 0)
61 /* error out, should never happen */
62 goto end;
63
64 if (g_cancellable_is_cancelled (cancellable))
65 {
66 /* CancelIO only cancels pending operations issued by the
67 * current thread and since we're doing only sync operations,
68 * this is safe.... */
69 /* CancelIoEx is only Vista+. Since we have only one overlap
70 * operation on this thread, we can just use: */
71 result = CancelIo (hfile);
72 g_warn_if_fail (result);
73 }
74
75 result = GetOverlappedResult (overlap->hEvent, overlap, transferred, FALSE);
76 if (result == FALSE &&
77 GetLastError () == ERROR_IO_INCOMPLETE &&
78 !g_cancellable_is_cancelled (cancellable))
79 goto loop;
80
81 end:
82 if (num > 1)
83 g_cancellable_release_fd (cancellable);
84
85 return result;
86 }
87 #endif
88