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 56static int was_et = 0; 57 58static 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 66static void 67read_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 82static void 83test_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 132end: 133 if (ev) { 134 event_del(ev); 135 event_free(ev); 136 } 137} 138 139static void 140test_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 175end: 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 184static int read_notification_count; 185static int last_read_notification_was_et; 186static void 187read_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 193static int write_notification_count; 194static int last_write_notification_was_et; 195static void 196write_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 */ 208static void 209test_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 259end: 260 if (read_ev) 261 event_free(read_ev); 262 if (write_ev) 263 event_free(write_ev); 264} 265 266struct 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