1/*
2 * waits for input
3 */
4/*
5Copyright 1987, 1998  The Open Group
6
7Permission to use, copy, modify, distribute, and sell this software and its
8documentation for any purpose is hereby granted without fee, provided that
9the above copyright notice appear in all copies and that both that
10copyright notice and this permission notice appear in supporting
11documentation.
12
13The above copyright notice and this permission notice shall be included in
14all copies or substantial portions of the Software.
15
16THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
19OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
20AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22
23Except as contained in this notice, the name of The Open Group shall not be
24used in advertising or otherwise to promote the sale, use or other dealings
25in this Software without prior written authorization from The Open Group.
26 * Copyright 1990, 1991 Network Computing Devices;
27 * Portions Copyright 1987 by Digital Equipment Corporation
28 *
29 * Permission to use, copy, modify, distribute, and sell this software and its
30 * documentation for any purpose is hereby granted without fee, provided that
31 * the above copyright notice appear in all copies and that both that
32 * copyright notice and this permission notice appear in supporting
33 * documentation, and that the names of Network Computing Devices,
34 * or Digital not be used in advertising or
35 * publicity pertaining to distribution of the software without specific,
36 * written prior permission.  Network Computing Devices, or Digital
37 * make no representations about the
38 * suitability of this software for any purpose.  It is provided "as is"
39 * without express or implied warranty.
40 *
41 * NETWORK COMPUTING DEVICES, AND DIGITAL DISCLAIM ALL WARRANTIES WITH
42 * REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
43 * AND FITNESS, IN NO EVENT SHALL NETWORK COMPUTING DEVICES, OR DIGITAL BE
44 * LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
45 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
46 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
47 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
48 *
49 */
50
51#include	"config.h"
52
53#include	<X11/Xos.h>	/* strings, time, etc */
54
55#include	<stdio.h>
56#include	<errno.h>
57#include	<sys/param.h>
58
59#include	"clientstr.h"
60#include	"globals.h"
61#include	"X11/Xpoll.h"
62#include	"osdep.h"
63#include	"os.h"
64
65
66long        LastReapTime;
67int         xfd_ffs(fd_mask);
68
69
70/* like ffs, but uses fd_mask instead of int as argument, so it works
71   when fd_mask is longer than an int, such as common 64-bit platforms */
72int
73xfd_ffs(fd_mask mask)
74{
75    int i;
76
77    if (!mask) return 0;
78
79    for (i = 1; !(mask & 1); i++)
80    {
81        mask >>= 1;
82    }
83    return i;
84}
85
86
87/*
88 * wait_for_something
89 *
90 * server suspends until
91 * - data from clients
92 * - new client connects
93 * - room to write data to clients
94 */
95
96int
97WaitForSomething(int *pClientsReady)
98{
99    struct timeval *wt,
100                waittime;
101    fd_set      clientsReadable;
102    fd_set      clientsWriteable;
103    long        curclient;
104    int         selecterr;
105    long        current_time = 0;
106    long        timeout;
107    int         nready,
108                i;
109
110    while (1) {
111	/* handle the work Q */
112	if (workQueue)
113	    ProcessWorkQueue();
114
115	if (XFD_ANYSET(&ClientsWithInput)) {
116	    XFD_COPYSET(&ClientsWithInput, &clientsReadable);
117	    break;
118	}
119	/*
120	 * deal with KeepAlive timeouts.  if this seems to costly, SIGALRM
121	 * could be used, but its more dangerous since some it could catch us
122	 * at an inopportune moment (like inside un-reentrant malloc()).
123	 */
124	current_time = GetTimeInMillis();
125	timeout = current_time - LastReapTime;
126	if (timeout > ReapClientTime) {
127	    ReapAnyOldClients();
128	    LastReapTime = current_time;
129	    timeout = ReapClientTime;
130	}
131	timeout = ReapClientTime - timeout;
132	waittime.tv_sec = timeout / MILLI_PER_SECOND;
133	waittime.tv_usec = (timeout % MILLI_PER_SECOND) *
134	    (1000000 / MILLI_PER_SECOND);
135	wt = &waittime;
136
137	XFD_COPYSET(&AllSockets, &LastSelectMask);
138
139	BlockHandler(&wt, (pointer) &LastSelectMask);
140	if (NewOutputPending)
141	    FlushAllOutput();
142
143	if (AnyClientsWriteBlocked) {
144	    XFD_COPYSET(&ClientsWriteBlocked, &clientsWriteable);
145	    i = Select(MAXSOCKS, &LastSelectMask, &clientsWriteable, NULL, wt);
146	} else {
147	    i = Select(MAXSOCKS, &LastSelectMask, NULL, NULL, wt);
148	}
149	selecterr = errno;
150
151	WakeupHandler(i, (unsigned long *) &LastSelectMask);
152	if (i <= 0) {		/* error or timeout */
153	    FD_ZERO(&clientsWriteable);
154	    if (i < 0) {
155		if (selecterr == EBADF) {	/* somebody disconnected */
156		    CheckConnections();
157		} else if (selecterr != EINTR) {
158		    ErrorF("WaitForSomething: select(): errno %d\n", selecterr);
159		} else {
160		    /*
161		     * must have been broken by a signal.  go deal with any
162		     * exception flags
163		     */
164		    return 0;
165		}
166	    } else {		/* must have timed out */
167		ReapAnyOldClients();
168		LastReapTime = GetTimeInMillis();
169	    }
170	} else {
171	    if (AnyClientsWriteBlocked && XFD_ANYSET(&clientsWriteable)) {
172		NewOutputPending = TRUE;
173		XFD_ORSET(&OutputPending, &clientsWriteable, &OutputPending);
174		XFD_UNSET(&ClientsWriteBlocked, &clientsWriteable);
175		if (!XFD_ANYSET(&ClientsWriteBlocked))
176		    AnyClientsWriteBlocked = FALSE;
177	    }
178	    XFD_ANDSET(&clientsReadable, &LastSelectMask, &AllClients);
179	    if (LastSelectMask.fds_bits[0] & WellKnownConnections.fds_bits[0])
180		MakeNewConnections();
181	    if (XFD_ANYSET(&clientsReadable))
182		break;
183
184	}
185    }
186    nready = 0;
187
188    if (XFD_ANYSET(&clientsReadable)) {
189	ClientPtr   client;
190	int         conn;
191
192	if (current_time)	/* may not have been set */
193	    current_time = GetTimeInMillis();
194	for (i = 0; i < howmany(XFD_SETSIZE, NFDBITS); i++) {
195	    while (clientsReadable.fds_bits[i]) {
196		curclient = xfd_ffs(clientsReadable.fds_bits[i]) - 1;
197		conn = ConnectionTranslation[curclient + (i * (sizeof(fd_mask) * 8))];
198		clientsReadable.fds_bits[i] &= ~(((fd_mask)1L) << curclient);
199		client = clients[conn];
200		if (!client)
201		    continue;
202		pClientsReady[nready++] = conn;
203		client->last_request_time = current_time;
204		client->clientGone = CLIENT_ALIVE;
205
206		if (nready >= MaxClients) {
207		    /* pClientsReady buffer has no more room, get the
208		       rest on the next time through select() loop */
209		    return nready;
210		}
211	    }
212	}
213    }
214    return nready;
215}
216