summaryrefslogtreecommitdiff
path: root/sched.c
blob: c2e00dfdc17391bb2865ba333d58a1f8a1568926 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
/* Copyright (c) 2008, 2009
 *      Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
 *      Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
 *      Micah Cowan (micah@cowan.name)
 *      Sadrul Habib Chowdhury (sadrul@users.sourceforge.net)
 * Copyright (c) 1993-2002, 2003, 2005, 2006, 2007
 *      Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
 *      Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
 * Copyright (c) 1987 Oliver Laumann
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program (see the file COPYING); if not, see
 * http://www.gnu.org/licenses/, or contact Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA
 *
 ****************************************************************
 */

#include <sys/types.h>
#if !defined(sun) && !defined(B43) && !defined(ISC) && !defined(pyr) && !defined(_CX_UX)
# include <time.h>
#endif
#include <sys/time.h>

#include "config.h"
#include "screen.h"
#include "extern.h"

static struct event *evs;
static struct event *tevs;
static struct event *nextev;
static int calctimeout;

static struct event *calctimo __P((void));
#if (defined(sgi) && defined(SVR4)) || defined(__osf__) || defined(M_UNIX)
static int sgihack __P((void));
#endif

void
evenq(ev)
struct event *ev;
{
  struct event *evp, **evpp;
  debug3("New event fd %d type %d queued %d\n", ev->fd, ev->type, ev->queued);
  if (ev->queued)
    return;
  evpp = &evs;
  if (ev->type == EV_TIMEOUT)
    {
      calctimeout = 1;
      evpp = &tevs;
    }
  for (; (evp = *evpp); evpp = &evp->next)
    if (ev->pri > evp->pri)
      break;
  ev->next = evp;
  *evpp = ev;
  ev->queued = 1;
}

void
evdeq(ev)
struct event *ev;
{
  struct event *evp, **evpp;
  debug3("Deq event fd %d type %d queued %d\n", ev->fd, ev->type, ev->queued);
  if (!ev->queued)
    return;
  evpp = &evs;
  if (ev->type == EV_TIMEOUT)
    {
      calctimeout = 1;
      evpp = &tevs;
    }
  for (; (evp = *evpp); evpp = &evp->next)
    if (evp == ev)
      break;
  ASSERT(evp);
  *evpp = ev->next;
  ev->queued = 0;
  if (ev == nextev)
    nextev = nextev->next;
}

static struct event *
calctimo()
{
  struct event *ev, *min;
  long mins;

  if ((min = tevs) == 0)
    return 0;
  mins = min->timeout.tv_sec;
  for (ev = tevs->next; ev; ev = ev->next)
    {
      ASSERT(ev->type == EV_TIMEOUT);
      if (mins < ev->timeout.tv_sec)
	continue;
      if (mins > ev->timeout.tv_sec || min->timeout.tv_usec > ev->timeout.tv_usec)
	{
	  min = ev;
	  mins = ev->timeout.tv_sec;
	}
    }
  return min;
}

void
sched()
{
  struct event *ev;
  fd_set r, w, *set;
  struct event *timeoutev = 0;
  struct timeval timeout;
  int nsel;

  for (;;)
    {
      if (calctimeout)
	timeoutev = calctimo();
      if (timeoutev)
	{
	  gettimeofday(&timeout, NULL);
	  /* tp - timeout */
	  timeout.tv_sec = timeoutev->timeout.tv_sec - timeout.tv_sec;
	  timeout.tv_usec = timeoutev->timeout.tv_usec - timeout.tv_usec;
	  if (timeout.tv_usec < 0)
	    {
	      timeout.tv_usec += 1000000;
	      timeout.tv_sec--;
	    }
	  if (timeout.tv_sec < 0)
	    {
	      timeout.tv_usec = 0;
	      timeout.tv_sec = 0;
	    }
	}
#ifdef DEBUG
      debug("waiting for events");
      if (timeoutev)
        debug2(" timeout %d secs %d usecs", timeout.tv_sec, timeout.tv_usec);
      debug(":\n");
      for (ev = evs; ev; ev = ev->next)
        debug3(" - fd %d type %d pri %d\n", ev->fd, ev->type, ev->pri);
      if (tevs)
        debug("timed events:\n");
      for (ev = tevs; ev; ev = ev->next)
        debug3(" - pri %d sec %d usec %d\n", ev->pri, ev->timeout.tv_sec, ev->timeout.tv_usec);
#endif

      FD_ZERO(&r);
      FD_ZERO(&w);
      for (ev = evs; ev; ev = ev->next)
        {
	  if (ev->condpos && *ev->condpos <= (ev->condneg ? *ev->condneg : 0))
	    {
	      debug2(" - cond ev fd %d type %d failed\n", ev->fd, ev->type);
	      continue;
	    }
	  if (ev->type == EV_READ)
	    FD_SET(ev->fd, &r);
	  else if (ev->type == EV_WRITE)
	    FD_SET(ev->fd, &w);
        }

#ifdef DEBUG
      debug("readfds:");
      for (nsel = 0; nsel < FD_SETSIZE; nsel++)
	if (FD_ISSET(nsel, &r))
	  debug1(" %d", nsel);
      debug("\n");
      debug("writefds:");
      for (nsel = 0; nsel < FD_SETSIZE; nsel++)
	if (FD_ISSET(nsel, &w))
	  debug1(" %d", nsel);
      debug("\n");
#endif

      nsel = select(FD_SETSIZE, &r, &w, (fd_set *)0, timeoutev ? &timeout : (struct timeval *) 0);
      if (nsel < 0)
	{
	  if (errno != EINTR)
	    {
#if defined(sgi) && defined(SVR4)
	      if (errno == EIO && sgihack())
		continue;
#endif
#if defined(__osf__) || defined(M_UNIX)
	      /* OSF/1 3.x, SCO bug: EBADF */
	      /* OSF/1 4.x bug: EIO */
	      if ((errno == EIO || errno == EBADF) && sgihack())
		continue;
#endif
	      Panic(errno, "select");
	    }
	  nsel = 0;
	}
      else if (nsel == 0)	/* timeout */
	{
	  debug("TIMEOUT!\n");
	  ASSERT(timeoutev);
	  evdeq(timeoutev);
	  timeoutev->handler(timeoutev, timeoutev->data);
	}
#ifdef SELECT_BROKEN
      /*
       * Sequents select emulation counts a descriptor which is
       * readable and writeable only as one hit. Waaaaa.
       */
      if (nsel)
        nsel = 2 * FD_SETSIZE;
#endif

      for (ev = evs; ev; ev = nextev)
        {
          nextev = ev->next;
	  if (ev->type != EV_ALWAYS)
	    {
	      set = ev->type == EV_READ ? &r : &w;
	      if (nsel == 0 || !FD_ISSET(ev->fd, set))
		continue;
	      nsel--;
	    }
	  if (ev->condpos && *ev->condpos <= (ev->condneg ? *ev->condneg : 0))
	    continue;
	  debug2(" + hit ev fd %d type %d!\n", ev->fd, ev->type);
	  ev->handler(ev, ev->data);
        }
    }
}

void
SetTimeout(ev, timo)
struct event *ev;
int timo;
{
  ASSERT(ev->type == EV_TIMEOUT);
  debug2("event %x new timeout %d ms\n", ev, timo);
  gettimeofday(&ev->timeout, NULL);
  ev->timeout.tv_sec  += timo / 1000;
  ev->timeout.tv_usec += (timo % 1000) * 1000;
  if (ev->timeout.tv_usec > 1000000)
    {
      ev->timeout.tv_usec -= 1000000;
      ev->timeout.tv_sec++;
    }
  if (ev->queued)
    calctimeout = 1;
}


#if (defined(sgi) && defined(SVR4)) || defined(__osf__) || defined(M_UNIX)

extern struct display *display, *displays;
static int sgihack()
{
  fd_set r, w;
  struct timeval tv;

  debug("IRIX5.2 workaround: searching for bad display\n");
  for (display = displays; display; )
    {
      FD_ZERO(&r);
      FD_ZERO(&w);
      FD_SET(D_userfd, &r);
      FD_SET(D_userfd, &w);
      tv.tv_sec = tv.tv_usec = 0;
      if (select(FD_SETSIZE, &r, &w, (fd_set *)0, &tv) == -1)
	{
	  if (errno == EINTR)
	    continue;
	  Hangup();	/* goodbye display */
	  return 1;
	}
      display = display->d_next;
    }
  return 0;
}

#endif