summaryrefslogtreecommitdiff
path: root/lib/libevent/kqueue.c
blob: 0e9ee45f0b28324d0503937b7194e5cf8e8ba5b5 (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
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
/*	$OpenBSD: kqueue.c,v 1.11 2004/01/05 19:20:18 markus Exp $	*/

/*
 * Copyright 2000-2002 Niels Provos <provos@citi.umich.edu>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Niels Provos.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <sys/types.h>
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <sys/_time.h>
#endif
#include <sys/queue.h>
#include <sys/event.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <err.h>
#ifdef HAVE_INTTYPES_H
#include <inttypes.h>
#endif

#ifdef USE_LOG
#include "log.h"
#else
#define LOG_DBG(x)
#define log_error	warn
#endif

#ifdef HAVE_INTTYPES_H
#define INTPTR(x)	(intptr_t)x
#else
#define INTPTR(x)	x
#endif

#include "event.h"

extern struct event_list timequeue;
extern struct event_list eventqueue;
extern struct event_list addqueue;

#define EVLIST_X_KQINKERNEL	0x1000

#define NEVENT		64

struct kqop {
	struct kevent *changes;
	int nchanges;
	struct kevent *events;
	int nevents;
	int kq;
} kqop;

void *kq_init	(void);
int kq_add	(void *, struct event *);
int kq_del	(void *, struct event *);
int kq_recalc	(void *, int);
int kq_dispatch	(void *, struct timeval *);

const struct eventop kqops = {
	"kqueue",
	kq_init,
	kq_add,
	kq_del,
	kq_recalc,
	kq_dispatch
};

void *
kq_init(void)
{
	int kq;

	/* Disable kqueue when this environment variable is set */
	if (!issetugid() && getenv("EVENT_NOKQUEUE"))
		return (NULL);

	memset(&kqop, 0, sizeof(kqop));

	/* Initialize the kernel queue */
	
	if ((kq = kqueue()) == -1) {
		log_error("kqueue");
		return (NULL);
	}

	kqop.kq = kq;

	/* Initialize fields */
	kqop.changes = malloc(NEVENT * sizeof(struct kevent));
	if (kqop.changes == NULL)
		return (NULL);
	kqop.events = malloc(NEVENT * sizeof(struct kevent));
	if (kqop.events == NULL) {
		free (kqop.changes);
		return (NULL);
	}
	kqop.nevents = NEVENT;

	return (&kqop);
}

int
kq_recalc(void *arg, int max)
{
	return (0);
}

int
kq_insert(struct kqop *kqop, struct kevent *kev)
{
	int nevents = kqop->nevents;

	if (kqop->nchanges == nevents) {
		struct kevent *newchange;
		struct kevent *newresult;

		nevents *= 2;

		newchange = realloc(kqop->changes,
				    nevents * sizeof(struct kevent));
		if (newchange == NULL) {
			log_error("%s: malloc", __func__);
			return (-1);
		}
		kqop->changes = newchange;

		newresult = realloc(kqop->changes,
				    nevents * sizeof(struct kevent));

		/*
		 * If we fail, we don't have to worry about freeing,
		 * the next realloc will pick it up.
		 */
		if (newresult == NULL) {
			log_error("%s: malloc", __func__);
			return (-1);
		}
		kqop->events = newchange;

		kqop->nevents = nevents;
	}

	memcpy(&kqop->changes[kqop->nchanges++], kev, sizeof(struct kevent));

	LOG_DBG((LOG_MISC, 70, "%s: fd %d %s%s",
		 __func__, kev->ident, 
		 kev->filter == EVFILT_READ ? "EVFILT_READ" : "EVFILT_WRITE",
		 kev->flags == EV_DELETE ? " (del)" : ""));

	return (0);
}

static void
kq_sighandler(int sig)
{
	/* Do nothing here */
}

int
kq_dispatch(void *arg, struct timeval *tv)
{
	struct kqop *kqop = arg;
	struct kevent *changes = kqop->changes;
	struct kevent *events = kqop->events;
	struct event *ev;
	struct timespec ts;
	int i, res;

	TIMEVAL_TO_TIMESPEC(tv, &ts);

	res = kevent(kqop->kq, changes, kqop->nchanges,
	    events, kqop->nevents, &ts);
	kqop->nchanges = 0;
	if (res == -1) {
		if (errno != EINTR) {
			log_error("kevent");
			return (-1);
		}

		return (0);
	}

	LOG_DBG((LOG_MISC, 80, "%s: kevent reports %d", __func__, res));

	for (i = 0; i < res; i++) {
		int which = 0;

		if (events[i].flags & EV_ERROR) {
			/* 
			 * Error messages that can happen, when a delete fails.
			 *   EBADF happens when the file discriptor has been
			 *   closed,
			 *   ENOENT when the file discriptor was closed and
			 *   then reopened.
			 * An error is also indicated when a callback deletes
			 * an event we are still processing.  In that case
			 * the data field is set to ENOENT.
			 */
			if (events[i].data == EBADF ||
			    events[i].data == ENOENT)
				continue;
			return (-1);
		}

		ev = (struct event *)events[i].udata;

		if (events[i].filter == EVFILT_READ) {
			which |= EV_READ;
		} else if (events[i].filter == EVFILT_WRITE) {
			which |= EV_WRITE;
		} else if (events[i].filter == EVFILT_SIGNAL) {
			which |= EV_SIGNAL;
		}

		if (!which)
			continue;

		if (!(ev->ev_events & EV_PERSIST)) {
			ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
			event_del(ev);
		}

		event_active(ev, which,
		    ev->ev_events & EV_SIGNAL ? events[i].data : 1);
	}

	return (0);
}


int
kq_add(void *arg, struct event *ev)
{
	struct kqop *kqop = arg;
	struct kevent kev;

	if (ev->ev_events & EV_SIGNAL) {
		int nsignal = EVENT_SIGNAL(ev);

 		memset(&kev, 0, sizeof(kev));
		kev.ident = nsignal;
		kev.filter = EVFILT_SIGNAL;
		kev.flags = EV_ADD;
		if (!(ev->ev_events & EV_PERSIST))
			kev.flags |= EV_ONESHOT;
		kev.udata = INTPTR(ev);
		
		if (kq_insert(kqop, &kev) == -1)
			return (-1);

		if (signal(nsignal, kq_sighandler) == SIG_ERR)
			return (-1);

		ev->ev_flags |= EVLIST_X_KQINKERNEL;
		return (0);
	}

	if (ev->ev_events & EV_READ) {
 		memset(&kev, 0, sizeof(kev));
		kev.ident = ev->ev_fd;
		kev.filter = EVFILT_READ;
		kev.flags = EV_ADD;
		/* Make it behave like select() and poll() */
		kev.fflags = NOTE_EOF;
		if (!(ev->ev_events & EV_PERSIST))
			kev.flags |= EV_ONESHOT;
		kev.udata = INTPTR(ev);
		
		if (kq_insert(kqop, &kev) == -1)
			return (-1);

		ev->ev_flags |= EVLIST_X_KQINKERNEL;
	}

	if (ev->ev_events & EV_WRITE) {
 		memset(&kev, 0, sizeof(kev));
		kev.ident = ev->ev_fd;
		kev.filter = EVFILT_WRITE;
		kev.flags = EV_ADD;
		if (!(ev->ev_events & EV_PERSIST))
			kev.flags |= EV_ONESHOT;
		kev.udata = INTPTR(ev);
		
		if (kq_insert(kqop, &kev) == -1)
			return (-1);

		ev->ev_flags |= EVLIST_X_KQINKERNEL;
	}

	return (0);
}

int
kq_del(void *arg, struct event *ev)
{
	struct kqop *kqop = arg;
	struct kevent kev;

	if (!(ev->ev_flags & EVLIST_X_KQINKERNEL))
		return (0);

	if (ev->ev_events & EV_SIGNAL) {
		int nsignal = EVENT_SIGNAL(ev);

 		memset(&kev, 0, sizeof(kev));
		kev.ident = (int)signal;
		kev.filter = EVFILT_SIGNAL;
		kev.flags = EV_DELETE;
		
		if (kq_insert(kqop, &kev) == -1)
			return (-1);

		if (signal(nsignal, SIG_DFL) == SIG_ERR)
			return (-1);

		ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
		return (0);
	}

	if (ev->ev_events & EV_READ) {
 		memset(&kev, 0, sizeof(kev));
		kev.ident = ev->ev_fd;
		kev.filter = EVFILT_READ;
		kev.flags = EV_DELETE;
		
		if (kq_insert(kqop, &kev) == -1)
			return (-1);

		ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
	}

	if (ev->ev_events & EV_WRITE) {
 		memset(&kev, 0, sizeof(kev));
		kev.ident = ev->ev_fd;
		kev.filter = EVFILT_WRITE;
		kev.flags = EV_DELETE;
		
		if (kq_insert(kqop, &kev) == -1)
			return (-1);

		ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
	}

	return (0);
}