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
52 static int was_et = 0;
53
base_supports_et(struct event_base * base)54 static 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
62 static void
read_cb(evutil_socket_t fd,short event,void * arg)63 read_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
78 static void
test_edgetriggered(void * data_)79 test_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
128 end:
129 if (ev) {
130 event_del(ev);
131 event_free(ev);
132 }
133 }
134
135 static void
test_edgetriggered_mix_error(void * data_)136 test_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
171 end:
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
180 static int read_notification_count;
181 static int last_read_notification_was_et;
182 static void
read_notification_cb(evutil_socket_t fd,short event,void * arg)183 read_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
189 static int write_notification_count;
190 static int last_write_notification_was_et;
191 static void
write_notification_cb(evutil_socket_t fd,short event,void * arg)192 write_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 */
204 static void
test_edge_triggered_multiple_events(void * data_)205 test_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
255 end:
256 if (read_ev)
257 event_free(read_ev);
258 if (write_ev)
259 event_free(write_ev);
260 }
261
262 struct 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