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
47 o http://msdn.microsoft.com/library/default.asp?
48 url=/library/en-us/dnmgmt/html/msdn_getpeek.asp
49 o http://developer.novell.com/support/winsock/doc/toc.htm
53 int silc_select(int n, fd_set *readfds, fd_set *writefds,
54 fd_set *exceptfds, struct timeval *timeout)
56 HANDLE handles[MAXIMUM_WAIT_OBJECTS];
57 DWORD ready, curtime, timeo;
61 /* Check fd sets (ignoring the exceptfds) */
63 for (i = 0; i < n - 1; i++)
64 if (FD_ISSET(i, readfds))
65 handles[nhandles++] = (HANDLE)i;
70 /* If writefds is set then return immediately */
72 for (i = 0; i < n - 1; i++)
73 if (FD_ISSET(i, writefds))
77 timeo = (timeout ? (timeout->tv_sec * 1000) + (timeout->tv_usec / 1000) :
80 /* If we have nothing to wait and timeout is set then register a timeout
81 and wait just for windows messages. */
82 if (nhandles == 0 && timeout) {
83 UINT timer = SetTimer(NULL, 0, timeo, NULL);
84 curtime = GetTickCount();
87 KillTimer(NULL, timer);
89 while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
90 if (msg.message == WM_TIMER)
92 TranslateMessage(&msg);
93 DispatchMessage(&msg);
96 if (timeo != INFINITE) {
97 timeo -= GetTickCount() - curtime;
101 timer = SetTimer(NULL, 0, timeo, NULL);
106 curtime = GetTickCount();
107 ready = MsgWaitForMultipleObjects(nhandles, handles, FALSE, timeo,
110 if (ready == WAIT_FAILED) {
111 /* Wait failed with error */
112 SILC_LOG_WARNING(("WaitForMultipleObjects() failed"));
115 } else if (ready >= WAIT_ABANDONED_0 &&
116 ready < WAIT_ABANDONED_0 + nhandles) {
117 /* Signal abandoned */
118 SILC_LOG_WARNING(("WaitForMultipleObjects() failed (ABANDONED)"));
120 } else if (ready == WAIT_TIMEOUT) {
123 } else if (ready == WAIT_OBJECT_0 + nhandles) {
124 /* Windows messages. The MSDN online says that if the application
125 creates a window then its main loop (and we're assuming that
126 it is our SILC Scheduler) must handle the Windows messages, so do
127 it here as the MSDN suggests. */
128 while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
129 TranslateMessage(&msg);
130 DispatchMessage(&msg);
133 /* If timeout is set then we must update the timeout since we won't
134 return and we will give the wait another try. */
135 if (timeo != INFINITE) {
136 timeo -= GetTickCount() - curtime;
141 /* Give the wait another try */
143 } else if (ready >= WAIT_OBJECT_0 && ready < WAIT_OBJECT_0 + nhandles &&
145 /* Some other event, like SOCKET or something. */
147 /* Go through all fds even though only one was set. This is to avoid
148 starvation of high numbered fds. */
149 ready -= WAIT_OBJECT_0;
152 /* Set the handle to fd set */
153 FD_SET((int)handles[ready], readfds);
156 /* Check the status of the next handle and set it's fd to the fd
157 set if data is available. */
159 if (WaitForSingleObject(handles[ready], 0) == WAIT_OBJECT_0)