1 /* $NetBSD: regress_et.c,v 1.6 2024/08/18 20:47:23 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 31 #ifdef _WIN32 32 #include <winsock2.h> 33 #endif 34 #include <sys/types.h> 35 #include <sys/stat.h> 36 #ifdef EVENT__HAVE_SYS_SOCKET_H 37 #include <sys/socket.h> 38 #endif 39 #include <fcntl.h> 40 #include <stdlib.h> 41 #include <stdio.h> 42 #include <string.h> 43 #ifndef _WIN32 44 #include <sys/time.h> 45 #include <unistd.h> 46 #endif 47 #include <errno.h> 48 49 #include "event2/event.h" 50 #include "event2/util.h" 51 52 #include "regress.h" 53 54 static int was_et = 0; 55 56 static int base_supports_et(struct event_base *base) 57 { 58 return 59 (!strcmp(event_base_get_method(base), "epoll") || 60 !strcmp(event_base_get_method(base), "epoll (with changelist)") || 61 !strcmp(event_base_get_method(base), "kqueue")); 62 } 63 64 static void 65 read_cb(evutil_socket_t fd, short event, void *arg) 66 { 67 char buf; 68 int len; 69 70 len = recv(fd, &buf, sizeof(buf), 0); 71 72 called++; 73 if (event & EV_ET) 74 was_et = 1; 75 76 if (!len) 77 event_del(arg); 78 } 79 80 static void 81 test_edgetriggered(void *data_) 82 { 83 struct basic_test_data *data = data_; 84 struct event_base *base = data->base; 85 evutil_socket_t *pair = data->pair; 86 struct event *ev = NULL; 87 const char *test = "test string"; 88 int supports_et; 89 90 /* On Linux 3.2.1 (at least, as patched by Fedora and tested by Nick), 91 * doing a "recv" on an AF_UNIX socket resets the readability of the 92 * socket, even though there is no state change, so we don't actually 93 * get edge-triggered behavior. Yuck! Linux 3.1.9 didn't have this 94 * problem. 95 */ 96 97 called = was_et = 0; 98 99 tt_int_op(send(pair[0], test, (int)strlen(test)+1, 0), >, 0); 100 tt_int_op(shutdown(pair[0], EVUTIL_SHUT_WR), ==, 0); 101 102 supports_et = base_supports_et(base); 103 TT_BLATHER(("Checking for edge-triggered events with %s, which should %s" 104 "support edge-triggering", event_base_get_method(base), 105 supports_et?"":"not ")); 106 107 /* Initialize one event */ 108 ev = event_new(base, pair[1], EV_READ|EV_ET|EV_PERSIST, read_cb, &ev); 109 tt_assert(ev != NULL); 110 tt_int_op(event_add(ev, NULL), ==, 0); 111 112 /* We're going to call the dispatch function twice. The first invocation 113 * will read a single byte from pair[1] in either case. If we're edge 114 * triggered, we'll only see the event once (since we only see transitions 115 * from no data to data), so the second invocation of event_base_loop will 116 * do nothing. If we're level triggered, the second invocation of 117 * event_base_loop will also activate the event (because there's still 118 * data to read). */ 119 tt_int_op(event_base_loop(base,EVLOOP_NONBLOCK|EVLOOP_ONCE), ==, 0); 120 tt_int_op(event_base_loop(base,EVLOOP_NONBLOCK|EVLOOP_ONCE), ==, 0); 121 122 if (supports_et) { 123 tt_int_op(called, ==, 1); 124 tt_assert(was_et); 125 } else { 126 tt_int_op(called, ==, 2); 127 tt_assert(!was_et); 128 } 129 130 end: 131 if (ev) { 132 event_del(ev); 133 event_free(ev); 134 } 135 } 136 137 static void 138 test_edgetriggered_mix_error(void *data_) 139 { 140 struct basic_test_data *data = data_; 141 struct event_base *base = NULL; 142 struct event *ev_et=NULL, *ev_lt=NULL; 143 144 #ifdef EVENT__DISABLE_DEBUG_MODE 145 if (1) 146 tt_skip(); 147 #endif 148 149 if (!libevent_tests_running_in_debug_mode) 150 event_enable_debug_mode(); 151 152 base = event_base_new(); 153 154 /* try mixing edge-triggered and level-triggered to make sure it fails*/ 155 ev_et = event_new(base, data->pair[0], EV_READ|EV_ET, read_cb, ev_et); 156 tt_assert(ev_et); 157 ev_lt = event_new(base, data->pair[0], EV_READ, read_cb, ev_lt); 158 tt_assert(ev_lt); 159 160 /* Add edge-triggered, then level-triggered. Get an error. */ 161 tt_int_op(0, ==, event_add(ev_et, NULL)); 162 tt_int_op(-1, ==, event_add(ev_lt, NULL)); 163 tt_int_op(EV_READ, ==, event_pending(ev_et, EV_READ, NULL)); 164 tt_int_op(0, ==, event_pending(ev_lt, EV_READ, NULL)); 165 166 tt_int_op(0, ==, event_del(ev_et)); 167 /* Add level-triggered, then edge-triggered. Get an error. */ 168 tt_int_op(0, ==, event_add(ev_lt, NULL)); 169 tt_int_op(-1, ==, event_add(ev_et, NULL)); 170 tt_int_op(EV_READ, ==, event_pending(ev_lt, EV_READ, NULL)); 171 tt_int_op(0, ==, event_pending(ev_et, EV_READ, NULL)); 172 173 end: 174 if (ev_et) 175 event_free(ev_et); 176 if (ev_lt) 177 event_free(ev_lt); 178 if (base) 179 event_base_free(base); 180 } 181 182 static int read_notification_count; 183 static int last_read_notification_was_et; 184 static void 185 read_notification_cb(evutil_socket_t fd, short event, void *arg) 186 { 187 read_notification_count++; 188 last_read_notification_was_et = (event & EV_ET); 189 } 190 191 static int write_notification_count; 192 static int last_write_notification_was_et; 193 static void 194 write_notification_cb(evutil_socket_t fd, short event, void *arg) 195 { 196 write_notification_count++; 197 last_write_notification_was_et = (event & EV_ET); 198 } 199 200 /* After two or more events have been registered for the same 201 * file descriptor using EV_ET, if one of the events is 202 * deleted, then the epoll_ctl() call issued by libevent drops 203 * the EPOLLET flag resulting in level triggered 204 * notifications. 205 */ 206 static void 207 test_edge_triggered_multiple_events(void *data_) 208 { 209 struct basic_test_data *data = data_; 210 struct event *read_ev = NULL; 211 struct event *write_ev = NULL; 212 const char c = 'A'; 213 struct event_base *base = data->base; 214 evutil_socket_t *pair = data->pair; 215 216 if (!base_supports_et(base)) { 217 tt_skip(); 218 return; 219 } 220 221 read_notification_count = 0; 222 last_read_notification_was_et = 0; 223 write_notification_count = 0; 224 last_write_notification_was_et = 0; 225 226 /* Make pair[1] readable */ 227 tt_int_op(send(pair[0], &c, 1, 0), >, 0); 228 229 read_ev = event_new(base, pair[1], EV_READ|EV_ET|EV_PERSIST, 230 read_notification_cb, NULL); 231 write_ev = event_new(base, pair[1], EV_WRITE|EV_ET|EV_PERSIST, 232 write_notification_cb, NULL); 233 234 event_add(read_ev, NULL); 235 event_add(write_ev, NULL); 236 event_base_loop(base, EVLOOP_NONBLOCK|EVLOOP_ONCE); 237 event_base_loop(base, EVLOOP_NONBLOCK|EVLOOP_ONCE); 238 239 tt_assert(last_read_notification_was_et); 240 tt_int_op(read_notification_count, ==, 1); 241 tt_assert(last_write_notification_was_et); 242 tt_int_op(write_notification_count, ==, 1); 243 244 event_del(read_ev); 245 246 /* trigger acitivity second time for the backend that can have multiple 247 * events for one fd (like kqueue) */ 248 close(pair[0]); 249 pair[0] = -1; 250 251 /* Verify that we are still edge-triggered for write notifications */ 252 event_base_loop(base, EVLOOP_NONBLOCK|EVLOOP_ONCE); 253 event_base_loop(base, EVLOOP_NONBLOCK|EVLOOP_ONCE); 254 tt_assert(last_write_notification_was_et); 255 tt_int_op(write_notification_count, ==, 2); 256 257 end: 258 if (read_ev) 259 event_free(read_ev); 260 if (write_ev) 261 event_free(write_ev); 262 } 263 264 struct testcase_t edgetriggered_testcases[] = { 265 { "et", test_edgetriggered, 266 TT_FORK|TT_NEED_BASE|TT_NEED_SOCKETPAIR, &basic_setup, NULL }, 267 { "et_mix_error", test_edgetriggered_mix_error, 268 TT_FORK|TT_NEED_SOCKETPAIR|TT_NO_LOGS, &basic_setup, NULL }, 269 { "et_multiple_events", test_edge_triggered_multiple_events, 270 TT_FORK|TT_NEED_BASE|TT_NEED_SOCKETPAIR, &basic_setup, NULL }, 271 END_OF_TESTCASES 272 }; 273