5 Author: Pekka Riikonen <priikone@silcnet.org>
7 Copyright (C) 2001 Pekka Riikonen
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
22 #include "silcincludes.h"
24 /* Our "select()" for WIN32. This mimics the behaviour of select() system
25 call. It does not call the Winsock's select() though. Its functions
26 are derived from GLib's g_poll() and from some old Xemacs's sys_select().
28 This makes following assumptions, which I don't know whether they
31 o writefds are ignored, if set this will return immediately.
32 o exceptfds are ignored totally
33 o If all arguments except timeout are NULL then this will register
34 a timeout with SetTimer and will wait just for Windows messages
36 o MsgWaitForMultipleObjects is used to wait all kind of events, this
37 includes SOCKETs and Windows messages.
38 o All Windows messages are dispatched from this function.
39 o The Operating System has Winsock 2.
43 o http://msdn.microsoft.com/library/default.asp?
44 url=/library/en-us/winui/hh/winui/messques_77zk.asp
48 int silc_select(int n, fd_set *readfds, fd_set *writefds,
49 fd_set *exceptfds, struct timeval *timeout)
51 HANDLE handles[MAXIMUM_WAIT_OBJECTS];
52 DWORD ready, curtime, timeo;
56 /* Check fd sets (ignoring the exceptfds) */
58 for (i = 0; i < n - 1; i++)
59 if (FD_ISSET(i, readfds))
60 handles[nhandles++] = (HANDLE)i;
65 /* If writefds is set then return immediately */
67 for (i = 0; i < n - 1; i++)
68 if (FD_ISSET(i, writefds))
72 timeo = (timeout ? (timeout.tv_sec * 1000) + (timeout.tv_usec / 1000) :
75 /* If we have nothing to wait and timeout is set then register a timeout
76 and wait just for windows messages. */
77 if (nhandles == 0 && timeout) {
78 UINT timer = SetTimer(NULL, 0, timeo, NULL);
81 KillTimer(NULL, timer);
83 while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
84 TranslateMessage(&msg);
85 DispatchMessage(&msg);
93 curtime = GetTickCount();
94 ready = MsgWaitForMultipleObjects(nhandles, handles, FALSE, timeo,
97 if (ready == WAIT_FAILED) {
98 /* Wait failed with error */
99 SILC_LOG_WARNING(("WaitForMultipleObjects() failed"));
102 } else if (ready >= WAIT_ABANDONED_0 &&
103 ready < WAIT_ABANDONED_0 + nhandles) {
104 /* Signal abandoned */
105 SILC_LOG_WARNING(("WaitForMultipleObjects() failed (ABANDONED)"));
107 } else if (ready == WAIT_TIMEOUT) {
110 } else if (ready == WAIT_OBJECT_0 + nhandles) {
111 /* Windows messages. The MSDN online says that if the application
112 creates a window then its main loop (and we're assuming that
113 it is our SILC Scheduler) must handle the Windows messages, so do
114 it here as the MSDN suggests. */
115 while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
116 TranslateMessage(&msg);
117 DispatchMessage(&msg);
120 /* If timeout is set then we must update the timeout since we won't
121 return and we will give the wait another try. */
122 if (timeo != INFINITE) {
123 timeo -= GetTickCount() - curtime;
128 /* Give the wait another try */
130 } else if (ready >= WAIT_OBJECT_0 && ready < WAIT_OBJECT_0 + nhandles &&
132 /* Some other event, like SOCKET or something. */
134 /* Go through all fds even though only one was set. This is to avoid
135 starvation of high numbered fds. */
136 ready -= WAIT_OBJECT_0;
139 /* Set the handle to fd set */
140 FD_SET(handle[ready], readfds);
143 /* Check the status of the next handle and set it's fd to the fd
144 set if data is available. */
146 if (WaitForSingleObject(handle[ready], 0) == WAIT_OBJECT_0)