1 /* $NetBSD: regress_et.c,v 1.4 2021/04/07 03:36:48 christos Exp $ */
2
3 /*
4 * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28 #include "../util-internal.h"
29 #include "event2/event-config.h"
30 #include <sys/cdefs.h>
31 __RCSID("$NetBSD: regress_et.c,v 1.4 2021/04/07 03:36:48 christos Exp $");
32
33 #ifdef _WIN32
34 #include <winsock2.h>
35 #endif
36 #include <sys/types.h>
37 #include <sys/stat.h>
38 #ifdef EVENT__HAVE_SYS_SOCKET_H
39 #include <sys/socket.h>
40 #endif
41 #include <fcntl.h>
42 #include <stdlib.h>
43 #include <stdio.h>
44 #include <string.h>
45 #ifndef _WIN32
46 #include <sys/time.h>
47 #include <unistd.h>
48 #endif
49 #include <errno.h>
50
51 #include "event2/event.h"
52 #include "event2/util.h"
53
54 #include "regress.h"
55
56 static int was_et = 0;
57
base_supports_et(struct event_base * base)58 static int base_supports_et(struct event_base *base)
59 {
60 return
61 (!strcmp(event_base_get_method(base), "epoll") ||
62 !strcmp(event_base_get_method(base), "epoll (with changelist)") ||
63 !strcmp(event_base_get_method(base), "kqueue"));
64 }
65
66 static void
read_cb(evutil_socket_t fd,short event,void * arg)67 read_cb(evutil_socket_t fd, short event, void *arg)
68 {
69 char buf;
70 int len;
71
72 len = recv(fd, &buf, sizeof(buf), 0);
73
74 called++;
75 if (event & EV_ET)
76 was_et = 1;
77
78 if (!len)
79 event_del(arg);
80 }
81
82 static void
test_edgetriggered(void * data_)83 test_edgetriggered(void *data_)
84 {
85 struct basic_test_data *data = data_;
86 struct event_base *base = data->base;
87 evutil_socket_t *xpair = data->pair;
88 struct event *ev = NULL;
89 const char *test = "test string";
90 int supports_et;
91
92 /* On Linux 3.2.1 (at least, as patched by Fedora and tested by Nick),
93 * doing a "recv" on an AF_UNIX socket resets the readability of the
94 * socket, even though there is no state change, so we don't actually
95 * get edge-triggered behavior. Yuck! Linux 3.1.9 didn't have this
96 * problem.
97 */
98
99 called = was_et = 0;
100
101 tt_int_op(send(xpair[0], test, (int)strlen(test)+1, 0), >, 0);
102 tt_int_op(shutdown(xpair[0], EVUTIL_SHUT_WR), ==, 0);
103
104 supports_et = base_supports_et(base);
105 TT_BLATHER(("Checking for edge-triggered events with %s, which should %s"
106 "support edge-triggering", event_base_get_method(base),
107 supports_et?"":"not "));
108
109 /* Initialize one event */
110 ev = event_new(base, xpair[1], EV_READ|EV_ET|EV_PERSIST, read_cb, &ev);
111 tt_assert(ev != NULL);
112 tt_int_op(event_add(ev, NULL), ==, 0);
113
114 /* We're going to call the dispatch function twice. The first invocation
115 * will read a single byte from xpair[1] in either case. If we're edge
116 * triggered, we'll only see the event once (since we only see transitions
117 * from no data to data), so the second invocation of event_base_loop will
118 * do nothing. If we're level triggered, the second invocation of
119 * event_base_loop will also activate the event (because there's still
120 * data to read). */
121 tt_int_op(event_base_loop(base,EVLOOP_NONBLOCK|EVLOOP_ONCE), ==, 0);
122 tt_int_op(event_base_loop(base,EVLOOP_NONBLOCK|EVLOOP_ONCE), ==, 0);
123
124 if (supports_et) {
125 tt_int_op(called, ==, 1);
126 tt_assert(was_et);
127 } else {
128 tt_int_op(called, ==, 2);
129 tt_assert(!was_et);
130 }
131
132 end:
133 if (ev) {
134 event_del(ev);
135 event_free(ev);
136 }
137 }
138
139 static void
test_edgetriggered_mix_error(void * data_)140 test_edgetriggered_mix_error(void *data_)
141 {
142 struct basic_test_data *data = data_;
143 struct event_base *base = NULL;
144 struct event *ev_et=NULL, *ev_lt=NULL;
145
146 #ifdef EVENT__DISABLE_DEBUG_MODE
147 if (1)
148 tt_skip();
149 #endif
150
151 if (!libevent_tests_running_in_debug_mode)
152 event_enable_debug_mode();
153
154 base = event_base_new();
155
156 /* try mixing edge-triggered and level-triggered to make sure it fails*/
157 ev_et = event_new(base, data->pair[0], EV_READ|EV_ET, read_cb, ev_et);
158 tt_assert(ev_et);
159 ev_lt = event_new(base, data->pair[0], EV_READ, read_cb, ev_lt);
160 tt_assert(ev_lt);
161
162 /* Add edge-triggered, then level-triggered. Get an error. */
163 tt_int_op(0, ==, event_add(ev_et, NULL));
164 tt_int_op(-1, ==, event_add(ev_lt, NULL));
165 tt_int_op(EV_READ, ==, event_pending(ev_et, EV_READ, NULL));
166 tt_int_op(0, ==, event_pending(ev_lt, EV_READ, NULL));
167
168 tt_int_op(0, ==, event_del(ev_et));
169 /* Add level-triggered, then edge-triggered. Get an error. */
170 tt_int_op(0, ==, event_add(ev_lt, NULL));
171 tt_int_op(-1, ==, event_add(ev_et, NULL));
172 tt_int_op(EV_READ, ==, event_pending(ev_lt, EV_READ, NULL));
173 tt_int_op(0, ==, event_pending(ev_et, EV_READ, NULL));
174
175 end:
176 if (ev_et)
177 event_free(ev_et);
178 if (ev_lt)
179 event_free(ev_lt);
180 if (base)
181 event_base_free(base);
182 }
183
184 static int read_notification_count;
185 static int last_read_notification_was_et;
186 static void
read_notification_cb(evutil_socket_t fd,short event,void * arg)187 read_notification_cb(evutil_socket_t fd, short event, void *arg)
188 {
189 read_notification_count++;
190 last_read_notification_was_et = (event & EV_ET);
191 }
192
193 static int write_notification_count;
194 static int last_write_notification_was_et;
195 static void
write_notification_cb(evutil_socket_t fd,short event,void * arg)196 write_notification_cb(evutil_socket_t fd, short event, void *arg)
197 {
198 write_notification_count++;
199 last_write_notification_was_et = (event & EV_ET);
200 }
201
202 /* After two or more events have been registered for the same
203 * file descriptor using EV_ET, if one of the events is
204 * deleted, then the epoll_ctl() call issued by libevent drops
205 * the EPOLLET flag resulting in level triggered
206 * notifications.
207 */
208 static void
test_edge_triggered_multiple_events(void * data_)209 test_edge_triggered_multiple_events(void *data_)
210 {
211 struct basic_test_data *data = data_;
212 struct event *read_ev = NULL;
213 struct event *write_ev = NULL;
214 const char c = 'A';
215 struct event_base *base = data->base;
216 evutil_socket_t *xpair = data->pair;
217
218 if (!base_supports_et(base)) {
219 tt_skip();
220 return;
221 }
222
223 read_notification_count = 0;
224 last_read_notification_was_et = 0;
225 write_notification_count = 0;
226 last_write_notification_was_et = 0;
227
228 /* Make xpair[1] readable */
229 tt_int_op(send(xpair[0], &c, 1, 0), >, 0);
230
231 read_ev = event_new(base, xpair[1], EV_READ|EV_ET|EV_PERSIST,
232 read_notification_cb, NULL);
233 write_ev = event_new(base, xpair[1], EV_WRITE|EV_ET|EV_PERSIST,
234 write_notification_cb, NULL);
235
236 event_add(read_ev, NULL);
237 event_add(write_ev, NULL);
238 event_base_loop(base, EVLOOP_NONBLOCK|EVLOOP_ONCE);
239 event_base_loop(base, EVLOOP_NONBLOCK|EVLOOP_ONCE);
240
241 tt_assert(last_read_notification_was_et);
242 tt_int_op(read_notification_count, ==, 1);
243 tt_assert(last_write_notification_was_et);
244 tt_int_op(write_notification_count, ==, 1);
245
246 event_del(read_ev);
247
248 /* trigger acitivity second time for the backend that can have multiple
249 * events for one fd (like kqueue) */
250 close(xpair[0]);
251 xpair[0] = -1;
252
253 /* Verify that we are still edge-triggered for write notifications */
254 event_base_loop(base, EVLOOP_NONBLOCK|EVLOOP_ONCE);
255 event_base_loop(base, EVLOOP_NONBLOCK|EVLOOP_ONCE);
256 tt_assert(last_write_notification_was_et);
257 tt_int_op(write_notification_count, ==, 2);
258
259 end:
260 if (read_ev)
261 event_free(read_ev);
262 if (write_ev)
263 event_free(write_ev);
264 }
265
266 struct testcase_t edgetriggered_testcases[] = {
267 { "et", test_edgetriggered,
268 TT_FORK|TT_NEED_BASE|TT_NEED_SOCKETPAIR, &basic_setup, NULL },
269 { "et_mix_error", test_edgetriggered_mix_error,
270 TT_FORK|TT_NEED_SOCKETPAIR|TT_NO_LOGS, &basic_setup, NULL },
271 { "et_multiple_events", test_edge_triggered_multiple_events,
272 TT_FORK|TT_NEED_BASE|TT_NEED_SOCKETPAIR, &basic_setup, NULL },
273 END_OF_TESTCASES
274 };
275