1 /*
2 * Copyright © 2014-2015 Red Hat, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24 #include "config.h"
25
26 #include <assert.h>
27 #include <errno.h>
28 #include <string.h>
29 #include <sys/timerfd.h>
30 #include <unistd.h>
31
32 #include "libinput-private.h"
33 #include "timer.h"
34
35 void
libinput_timer_init(struct libinput_timer * timer,struct libinput * libinput,const char * timer_name,void (* timer_func)(uint64_t now,void * timer_func_data),void * timer_func_data)36 libinput_timer_init(struct libinput_timer *timer,
37 struct libinput *libinput,
38 const char *timer_name,
39 void (*timer_func)(uint64_t now, void *timer_func_data),
40 void *timer_func_data)
41 {
42 timer->libinput = libinput;
43 timer->timer_name = safe_strdup(timer_name);
44 timer->timer_func = timer_func;
45 timer->timer_func_data = timer_func_data;
46 /* at most 5 "expiry in the past" log messages per hour */
47 ratelimit_init(&libinput->timer.expiry_in_past_limit,
48 s2us(60 * 60), 5);
49 }
50
51 void
libinput_timer_destroy(struct libinput_timer * timer)52 libinput_timer_destroy(struct libinput_timer *timer)
53 {
54 if (timer->link.prev != NULL && timer->link.next != NULL &&
55 !list_empty(&timer->link)) {
56 log_bug_libinput(timer->libinput,
57 "timer: %s has not been cancelled\n",
58 timer->timer_name);
59 assert(!"timer not cancelled");
60 }
61 free(timer->timer_name);
62 }
63
64 static void
libinput_timer_arm_timer_fd(struct libinput * libinput)65 libinput_timer_arm_timer_fd(struct libinput *libinput)
66 {
67 int r;
68 struct libinput_timer *timer;
69 struct itimerspec its = { { 0, 0 }, { 0, 0 } };
70 uint64_t earliest_expire = UINT64_MAX;
71
72 list_for_each(timer, &libinput->timer.list, link) {
73 if (timer->expire < earliest_expire)
74 earliest_expire = timer->expire;
75 }
76
77 if (earliest_expire != UINT64_MAX) {
78 its.it_value.tv_sec = earliest_expire / ms2us(1000);
79 its.it_value.tv_nsec = (earliest_expire % ms2us(1000)) * 1000;
80 }
81
82 r = timerfd_settime(libinput->timer.fd, TFD_TIMER_ABSTIME, &its, NULL);
83 if (r)
84 log_error(libinput, "timer: timerfd_settime error: %s\n", strerror(errno));
85
86 libinput->timer.next_expiry = earliest_expire;
87 }
88
89 void
libinput_timer_set_flags(struct libinput_timer * timer,uint64_t expire,uint32_t flags)90 libinput_timer_set_flags(struct libinput_timer *timer,
91 uint64_t expire,
92 uint32_t flags)
93 {
94 #ifndef NDEBUG
95 /* We only warn if we're more than 20ms behind */
96 const uint64_t timer_warning_limit = ms2us(20);
97 uint64_t now = libinput_now(timer->libinput);
98 if (expire < now) {
99 if ((flags & TIMER_FLAG_ALLOW_NEGATIVE) == 0 &&
100 now - expire > timer_warning_limit)
101 log_bug_client_ratelimit(timer->libinput,
102 &timer->libinput->timer.expiry_in_past_limit,
103 "timer %s: scheduled expiry is in the past (-%dms), your system is too slow\n",
104 timer->timer_name,
105 us2ms(now - expire));
106 } else if ((expire - now) > ms2us(5000)) {
107 log_bug_libinput(timer->libinput,
108 "timer %s: offset more than 5s, now %d expire %d\n",
109 timer->timer_name,
110 us2ms(now), us2ms(expire));
111 }
112 #endif
113
114 assert(expire);
115
116 if (!timer->expire)
117 list_insert(&timer->libinput->timer.list, &timer->link);
118
119 timer->expire = expire;
120 libinput_timer_arm_timer_fd(timer->libinput);
121 }
122
123 void
libinput_timer_set(struct libinput_timer * timer,uint64_t expire)124 libinput_timer_set(struct libinput_timer *timer, uint64_t expire)
125 {
126 libinput_timer_set_flags(timer, expire, TIMER_FLAG_NONE);
127 }
128
129 void
libinput_timer_cancel(struct libinput_timer * timer)130 libinput_timer_cancel(struct libinput_timer *timer)
131 {
132 if (!timer->expire)
133 return;
134
135 timer->expire = 0;
136 list_remove(&timer->link);
137 libinput_timer_arm_timer_fd(timer->libinput);
138 }
139
140 static void
libinput_timer_handler(struct libinput * libinput,uint64_t now)141 libinput_timer_handler(struct libinput *libinput , uint64_t now)
142 {
143 struct libinput_timer *timer;
144
145 restart:
146 list_for_each_safe(timer, &libinput->timer.list, link) {
147 if (timer->expire == 0)
148 continue;
149
150 if (timer->expire <= now) {
151 /* Clear the timer before calling timer_func,
152 as timer_func may re-arm it */
153 libinput_timer_cancel(timer);
154 timer->timer_func(now, timer->timer_func_data);
155
156 /*
157 * Restart the loop. We can't use
158 * list_for_each_safe() here because that only
159 * allows removing one (our) timer per timer_func.
160 * But the timer func may trigger another unrelated
161 * timer to be cancelled and removed, causing a
162 * segfault.
163 */
164 goto restart;
165 }
166 }
167 }
168
169 static void
libinput_timer_dispatch(void * data)170 libinput_timer_dispatch(void *data)
171 {
172 struct libinput *libinput = data;
173 uint64_t now;
174 uint64_t discard;
175 int r;
176
177 r = read(libinput->timer.fd, &discard, sizeof(discard));
178 if (r == -1 && errno != EAGAIN)
179 log_bug_libinput(libinput,
180 "timer: error %d reading from timerfd (%s)",
181 errno,
182 strerror(errno));
183
184 now = libinput_now(libinput);
185 if (now == 0)
186 return;
187
188 libinput_timer_handler(libinput, now);
189 }
190
191 int
libinput_timer_subsys_init(struct libinput * libinput)192 libinput_timer_subsys_init(struct libinput *libinput)
193 {
194 libinput->timer.fd = timerfd_create(CLOCK_MONOTONIC,
195 TFD_CLOEXEC | TFD_NONBLOCK);
196 if (libinput->timer.fd < 0)
197 return -1;
198
199 list_init(&libinput->timer.list);
200
201 libinput->timer.source = libinput_add_fd(libinput,
202 libinput->timer.fd,
203 libinput_timer_dispatch,
204 libinput);
205 if (!libinput->timer.source) {
206 close(libinput->timer.fd);
207 return -1;
208 }
209
210 return 0;
211 }
212
213 void
libinput_timer_subsys_destroy(struct libinput * libinput)214 libinput_timer_subsys_destroy(struct libinput *libinput)
215 {
216 #ifndef NDEBUG
217 if (!list_empty(&libinput->timer.list)) {
218 struct libinput_timer *t;
219
220 list_for_each(t, &libinput->timer.list, link) {
221 log_bug_libinput(libinput,
222 "timer: %s still present on shutdown\n",
223 t->timer_name);
224 }
225 }
226 #endif
227
228 /* All timer users should have destroyed their timers now */
229 assert(list_empty(&libinput->timer.list));
230
231 libinput_remove_source(libinput, libinput->timer.source);
232 close(libinput->timer.fd);
233 }
234
235 /**
236 * For a caller calling libinput_dispatch() only infrequently, we may have a
237 * timer expiry *and* a later input event waiting in the pipe. We cannot
238 * guarantee that we read the timer expiry first, so this hook exists to
239 * flush any timers.
240 *
241 * Assume 'now' is the current time check if there is a current timer expiry
242 * before this time. If so, trigger the timer func.
243 */
244 void
libinput_timer_flush(struct libinput * libinput,uint64_t now)245 libinput_timer_flush(struct libinput *libinput, uint64_t now)
246 {
247 if (libinput->timer.next_expiry == 0 ||
248 libinput->timer.next_expiry > now)
249 return;
250
251 libinput_timer_handler(libinput, now);
252 }
253