1/*
2 * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 * 3. The name of the author may not be used to endorse or promote products
13 *    derived from this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26#include "../util-internal.h"
27#include "event2/event-config.h"
28
29#ifdef _WIN32
30#include <winsock2.h>
31#endif
32#include <sys/types.h>
33#include <sys/stat.h>
34#ifdef EVENT__HAVE_SYS_SOCKET_H
35#include <sys/socket.h>
36#endif
37#include <fcntl.h>
38#include <stdlib.h>
39#include <stdio.h>
40#include <string.h>
41#ifndef _WIN32
42#include <sys/time.h>
43#include <unistd.h>
44#endif
45#include <errno.h>
46
47#include "event2/event.h"
48#include "event2/util.h"
49
50#include "regress.h"
51
52static int was_et = 0;
53
54static int base_supports_et(struct event_base *base)
55{
56	return
57		(!strcmp(event_base_get_method(base), "epoll") ||
58		!strcmp(event_base_get_method(base), "epoll (with changelist)") ||
59		!strcmp(event_base_get_method(base), "kqueue"));
60}
61
62static void
63read_cb(evutil_socket_t fd, short event, void *arg)
64{
65	char buf;
66	int len;
67
68	len = recv(fd, &buf, sizeof(buf), 0);
69
70	called++;
71	if (event & EV_ET)
72		was_et = 1;
73
74	if (!len)
75		event_del(arg);
76}
77
78static void
79test_edgetriggered(void *data_)
80{
81	struct basic_test_data *data = data_;
82	struct event_base *base = data->base;
83	evutil_socket_t *pair = data->pair;
84	struct event *ev = NULL;
85	const char *test = "test string";
86	int supports_et;
87
88	/* On Linux 3.2.1 (at least, as patched by Fedora and tested by Nick),
89	 * doing a "recv" on an AF_UNIX socket resets the readability of the
90	 * socket, even though there is no state change, so we don't actually
91	 * get edge-triggered behavior.  Yuck!  Linux 3.1.9 didn't have this
92	 * problem.
93	 */
94
95	called = was_et = 0;
96
97	tt_int_op(send(pair[0], test, (int)strlen(test)+1, 0), >, 0);
98	tt_int_op(shutdown(pair[0], EVUTIL_SHUT_WR), ==, 0);
99
100	supports_et = base_supports_et(base);
101	TT_BLATHER(("Checking for edge-triggered events with %s, which should %s"
102				"support edge-triggering", event_base_get_method(base),
103				supports_et?"":"not "));
104
105	/* Initialize one event */
106	ev = event_new(base, pair[1], EV_READ|EV_ET|EV_PERSIST, read_cb, &ev);
107	tt_assert(ev != NULL);
108	tt_int_op(event_add(ev, NULL), ==, 0);
109
110	/* We're going to call the dispatch function twice.  The first invocation
111	 * will read a single byte from pair[1] in either case.  If we're edge
112	 * triggered, we'll only see the event once (since we only see transitions
113	 * from no data to data), so the second invocation of event_base_loop will
114	 * do nothing.  If we're level triggered, the second invocation of
115	 * event_base_loop will also activate the event (because there's still
116	 * data to read). */
117	tt_int_op(event_base_loop(base,EVLOOP_NONBLOCK|EVLOOP_ONCE), ==, 0);
118	tt_int_op(event_base_loop(base,EVLOOP_NONBLOCK|EVLOOP_ONCE), ==, 0);
119
120	if (supports_et) {
121		tt_int_op(called, ==, 1);
122		tt_assert(was_et);
123	} else {
124		tt_int_op(called, ==, 2);
125		tt_assert(!was_et);
126	}
127
128end:
129	if (ev) {
130		event_del(ev);
131		event_free(ev);
132	}
133}
134
135static void
136test_edgetriggered_mix_error(void *data_)
137{
138	struct basic_test_data *data = data_;
139	struct event_base *base = NULL;
140	struct event *ev_et=NULL, *ev_lt=NULL;
141
142#ifdef EVENT__DISABLE_DEBUG_MODE
143	if (1)
144		tt_skip();
145#endif
146
147	if (!libevent_tests_running_in_debug_mode)
148		event_enable_debug_mode();
149
150	base = event_base_new();
151
152	/* try mixing edge-triggered and level-triggered to make sure it fails*/
153	ev_et = event_new(base, data->pair[0], EV_READ|EV_ET, read_cb, ev_et);
154	tt_assert(ev_et);
155	ev_lt = event_new(base, data->pair[0], EV_READ, read_cb, ev_lt);
156	tt_assert(ev_lt);
157
158	/* Add edge-triggered, then level-triggered.  Get an error. */
159	tt_int_op(0, ==, event_add(ev_et, NULL));
160	tt_int_op(-1, ==, event_add(ev_lt, NULL));
161	tt_int_op(EV_READ, ==, event_pending(ev_et, EV_READ, NULL));
162	tt_int_op(0, ==, event_pending(ev_lt, EV_READ, NULL));
163
164	tt_int_op(0, ==, event_del(ev_et));
165	/* Add level-triggered, then edge-triggered.  Get an error. */
166	tt_int_op(0, ==, event_add(ev_lt, NULL));
167	tt_int_op(-1, ==, event_add(ev_et, NULL));
168	tt_int_op(EV_READ, ==, event_pending(ev_lt, EV_READ, NULL));
169	tt_int_op(0, ==, event_pending(ev_et, EV_READ, NULL));
170
171end:
172	if (ev_et)
173		event_free(ev_et);
174	if (ev_lt)
175		event_free(ev_lt);
176	if (base)
177		event_base_free(base);
178}
179
180static int read_notification_count;
181static int last_read_notification_was_et;
182static void
183read_notification_cb(evutil_socket_t fd, short event, void *arg)
184{
185	read_notification_count++;
186	last_read_notification_was_et = (event & EV_ET);
187}
188
189static int write_notification_count;
190static int last_write_notification_was_et;
191static void
192write_notification_cb(evutil_socket_t fd, short event, void *arg)
193{
194	write_notification_count++;
195	last_write_notification_was_et = (event & EV_ET);
196}
197
198/* After two or more events have been registered for the same
199 * file descriptor using EV_ET, if one of the events is
200 * deleted, then the epoll_ctl() call issued by libevent drops
201 * the EPOLLET flag resulting in level triggered
202 * notifications.
203 */
204static void
205test_edge_triggered_multiple_events(void *data_)
206{
207	struct basic_test_data *data = data_;
208	struct event *read_ev = NULL;
209	struct event *write_ev = NULL;
210	const char c = 'A';
211	struct event_base *base = data->base;
212	evutil_socket_t *pair = data->pair;
213
214	if (!base_supports_et(base)) {
215		tt_skip();
216		return;
217	}
218
219	read_notification_count = 0;
220	last_read_notification_was_et = 0;
221	write_notification_count = 0;
222	last_write_notification_was_et = 0;
223
224	/* Make pair[1] readable */
225	tt_int_op(send(pair[0], &c, 1, 0), >, 0);
226
227	read_ev = event_new(base, pair[1], EV_READ|EV_ET|EV_PERSIST,
228		read_notification_cb, NULL);
229	write_ev = event_new(base, pair[1], EV_WRITE|EV_ET|EV_PERSIST,
230		write_notification_cb, NULL);
231
232	event_add(read_ev, NULL);
233	event_add(write_ev, NULL);
234	event_base_loop(base, EVLOOP_NONBLOCK|EVLOOP_ONCE);
235	event_base_loop(base, EVLOOP_NONBLOCK|EVLOOP_ONCE);
236
237	tt_assert(last_read_notification_was_et);
238	tt_int_op(read_notification_count, ==, 1);
239	tt_assert(last_write_notification_was_et);
240	tt_int_op(write_notification_count, ==, 1);
241
242	event_del(read_ev);
243
244	/* trigger acitivity second time for the backend that can have multiple
245	 * events for one fd (like kqueue) */
246	close(pair[0]);
247	pair[0] = -1;
248
249	/* Verify that we are still edge-triggered for write notifications */
250	event_base_loop(base, EVLOOP_NONBLOCK|EVLOOP_ONCE);
251	event_base_loop(base, EVLOOP_NONBLOCK|EVLOOP_ONCE);
252	tt_assert(last_write_notification_was_et);
253	tt_int_op(write_notification_count, ==, 2);
254
255end:
256	if (read_ev)
257		event_free(read_ev);
258	if (write_ev)
259		event_free(write_ev);
260}
261
262struct testcase_t edgetriggered_testcases[] = {
263	{ "et", test_edgetriggered,
264	  TT_FORK|TT_NEED_BASE|TT_NEED_SOCKETPAIR, &basic_setup, NULL },
265	{ "et_mix_error", test_edgetriggered_mix_error,
266	  TT_FORK|TT_NEED_SOCKETPAIR|TT_NO_LOGS, &basic_setup, NULL },
267	{ "et_multiple_events", test_edge_triggered_multiple_events,
268	  TT_FORK|TT_NEED_BASE|TT_NEED_SOCKETPAIR, &basic_setup, NULL },
269	END_OF_TESTCASES
270};
271