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
45 o http://msdn.microsoft.com/library/default.asp?
46 url=/library/en-us/winsock/hh/winsock/apistart_9g1e.asp
50 int silc_select(int n, fd_set *readfds, fd_set *writefds,
51 fd_set *exceptfds, struct timeval *timeout)
53 HANDLE handles[MAXIMUM_WAIT_OBJECTS];
54 DWORD ready, curtime, timeo;
58 /* Check fd sets (ignoring the exceptfds) */
60 for (i = 0; i < n - 1; i++)
61 if (FD_ISSET(i, readfds))
62 handles[nhandles++] = (HANDLE)i;
67 /* If writefds is set then return immediately */
69 for (i = 0; i < n - 1; i++)
70 if (FD_ISSET(i, writefds))
74 timeo = (timeout ? (timeout.tv_sec * 1000) + (timeout.tv_usec / 1000) :
77 /* If we have nothing to wait and timeout is set then register a timeout
78 and wait just for windows messages. */
79 if (nhandles == 0 && timeout) {
80 UINT timer = SetTimer(NULL, 0, timeo, NULL);
83 KillTimer(NULL, timer);
85 while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
86 TranslateMessage(&msg);
87 DispatchMessage(&msg);
95 curtime = GetTickCount();
96 ready = MsgWaitForMultipleObjects(nhandles, handles, FALSE, timeo,
99 if (ready == WAIT_FAILED) {
100 /* Wait failed with error */
101 SILC_LOG_WARNING(("WaitForMultipleObjects() failed"));
104 } else if (ready >= WAIT_ABANDONED_0 &&
105 ready < WAIT_ABANDONED_0 + nhandles) {
106 /* Signal abandoned */
107 SILC_LOG_WARNING(("WaitForMultipleObjects() failed (ABANDONED)"));
109 } else if (ready == WAIT_TIMEOUT) {
112 } else if (ready == WAIT_OBJECT_0 + nhandles) {
113 /* Windows messages. The MSDN online says that if the application
114 creates a window then its main loop (and we're assuming that
115 it is our SILC Scheduler) must handle the Windows messages, so do
116 it here as the MSDN suggests. */
117 while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
118 TranslateMessage(&msg);
119 DispatchMessage(&msg);
122 /* If timeout is set then we must update the timeout since we won't
123 return and we will give the wait another try. */
124 if (timeo != INFINITE) {
125 timeo -= GetTickCount() - curtime;
130 /* Give the wait another try */
132 } else if (ready >= WAIT_OBJECT_0 && ready < WAIT_OBJECT_0 + nhandles &&
134 /* Some other event, like SOCKET or something. */
136 /* Go through all fds even though only one was set. This is to avoid
137 starvation of high numbered fds. */
138 ready -= WAIT_OBJECT_0;
141 /* Set the handle to fd set */
142 FD_SET(handle[ready], readfds);
145 /* Check the status of the next handle and set it's fd to the fd
146 set if data is available. */
148 if (WaitForSingleObject(handle[ready], 0) == WAIT_OBJECT_0)