1 /*        $NetBSD: timevar.h,v 1.52 2024/12/22 23:24:20 riastradh Exp $         */
2 
3 /*
4  *  Copyright (c) 2005, 2008, 2020 The NetBSD Foundation, Inc.
5  *  All rights reserved.
6  *
7  *  Redistribution and use in source and binary forms, with or without
8  *  modification, are permitted provided that the following conditions
9  *  are met:
10  *  1. Redistributions of source code must retain the above copyright
11  *     notice, this list of conditions and the following disclaimer.
12  *  2. Redistributions in binary form must reproduce the above copyright
13  *     notice, this list of conditions and the following disclaimer in the
14  *     documentation and/or other materials provided with the distribution.
15  *
16  *  THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  *  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  *  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  *  PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  *  BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  *  POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * Copyright (c) 1982, 1986, 1993
31  *        The Regents of the University of California.  All rights reserved.
32  *
33  * Redistribution and use in source and binary forms, with or without
34  * modification, are permitted provided that the following conditions
35  * are met:
36  * 1. Redistributions of source code must retain the above copyright
37  *    notice, this list of conditions and the following disclaimer.
38  * 2. Redistributions in binary form must reproduce the above copyright
39  *    notice, this list of conditions and the following disclaimer in the
40  *    documentation and/or other materials provided with the distribution.
41  * 3. Neither the name of the University nor the names of its contributors
42  *    may be used to endorse or promote products derived from this software
43  *    without specific prior written permission.
44  *
45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55  * SUCH DAMAGE.
56  *
57  *        @(#)time.h          8.5 (Berkeley) 5/4/95
58  */
59 
60 #ifndef _SYS_TIMEVAR_H_
61 #define _SYS_TIMEVAR_H_
62 
63 #include <sys/atomic.h>
64 #include <sys/callout.h>
65 #include <sys/queue.h>
66 #include <sys/signal.h>
67 #include <sys/systm.h>
68 
69 struct itimer;
70 LIST_HEAD(itlist, itimer);
71 
72 /*
73  * Interval timer operations vector.
74  *
75  * Required fields:
76  *
77  *        - ito_fire: A function to be called when the itimer fires.
78  *          The timer implementation should perform whatever processing
79  *          is necessary for that timer type.
80  *
81  * Optional fields:
82  *
83  *        - ito_realtime_changed: A function that is called when the system
84  *          time (CLOCK_REALTIME) is called.
85  */
86 struct itimer_ops {
87           void      (*ito_fire)(struct itimer *);
88           void      (*ito_realtime_changed)(struct itimer *);
89 };
90 
91 /*
92  * Common interval timer data.
93  */
94 struct itimer {
95           union {
96                     struct {
97                               callout_t           it_ch;
98                               LIST_ENTRY(itimer)  it_rtchgq;
99                     } it_real;
100                     struct {
101                               struct itlist                 *it_vlist;
102                               LIST_ENTRY(itimer)  it_list;
103                               bool                          it_active;
104                     } it_virtual;
105           };
106           const struct itimer_ops *it_ops;
107           struct itimerspec it_time;
108           clockid_t it_clockid;
109           int       it_overruns;        /* Overruns currently accumulating */
110           bool      it_dying;
111 };
112 
113 #define   it_ch               it_real.it_ch
114 #define   it_rtchgq it_real.it_rtchgq
115 
116 #define   it_vlist  it_virtual.it_vlist
117 #define   it_list             it_virtual.it_list
118 #define   it_active it_virtual.it_active
119 
120 /*
121  * Structure used to manage timers in a process.
122  */
123 struct ptimer {
124           struct itimer pt_itimer;/* common interval timer data */
125 
126           TAILQ_ENTRY(ptimer) pt_chain; /* link in signalling queue */
127           struct    sigevent pt_ev;     /* event notification info */
128           int       pt_poverruns;       /* Overruns associated w/ a delivery */
129           int       pt_entry; /* slot in proc's timer table */
130           struct proc *pt_proc;         /* associated process */
131           bool      pt_queued;          /* true if linked into signalling queue */
132 };
133 
134 #define   TIMER_MIN 4         /* [0..3] are reserved for setitimer(2) */
135                                         /* REAL=0,VIRTUAL=1,PROF=2,MONOTONIC=3 */
136 #define   TIMER_MAX 36        /* 32 is minimum user timers per POSIX */
137 #define   TIMERS_ALL          0
138 #define   TIMERS_POSIX        1
139 
140 struct ptimers {
141           struct itlist pts_virtual;
142           struct itlist pts_prof;
143           struct itimer *pts_timers[TIMER_MAX];
144 };
145 
146 /*
147  * Functions for looking at our clock: [get]{bin,nano,micro}[up]time()
148  *
149  * Functions without the "get" prefix returns the best timestamp
150  * we can produce in the given format.
151  *
152  * "bin"   == struct bintime  == seconds + 64 bit fraction of seconds.
153  * "nano"  == struct timespec == seconds + nanoseconds.
154  * "micro" == struct timeval  == seconds + microseconds.
155  *
156  * Functions containing "up" returns time relative to boot and
157  * should be used for calculating time intervals.
158  *
159  * Functions without "up" returns GMT time.
160  *
161  * Functions with the "get" prefix returns a less precise result
162  * much faster than the functions without "get" prefix and should
163  * be used where a precision of 1/HZ (eg 10 msec on a 100HZ machine)
164  * is acceptable or where performance is priority.
165  * (NB: "precision", _not_ "resolution" !)
166  *
167  */
168 
169 void      binuptime(struct bintime *);
170 void      nanouptime(struct timespec *);
171 void      microuptime(struct timeval *);
172 
173 void      bintime(struct bintime *);
174 void      nanotime(struct timespec *);
175 void      microtime(struct timeval *);
176 
177 void      getbinuptime(struct bintime *);
178 void      getnanouptime(struct timespec *);
179 void      getmicrouptime(struct timeval *);
180 
181 void      getbintime(struct bintime *);
182 void      getnanotime(struct timespec *);
183 void      getmicrotime(struct timeval *);
184 
185 void      getbinboottime(struct bintime *);
186 void      getnanoboottime(struct timespec *);
187 void      getmicroboottime(struct timeval *);
188 
189 /* Other functions */
190 int       ts2timo(clockid_t, int, struct timespec *, int *, struct timespec *);
191 void      adjtime1(const struct timeval *, struct timeval *, struct proc *);
192 int       clock_getres1(clockid_t, struct timespec *);
193 int       clock_gettime1(clockid_t, struct timespec *);
194 int       clock_settime1(struct proc *, clockid_t, const struct timespec *, bool);
195 void      clock_timeleft(clockid_t, struct timespec *, struct timespec *);
196 int       dogetitimer(struct proc *, int, struct itimerval *);
197 int       dosetitimer(struct proc *, int, struct itimerval *);
198 int       dotimer_gettime(int, struct proc *, struct itimerspec *);
199 int       dotimer_settime(int, struct itimerspec *, struct itimerspec *, int,
200               struct proc *);
201 int       tshzto(const struct timespec *);
202 int       tshztoup(const struct timespec *);
203 int       tvhzto(const struct timeval *);
204 void      inittimecounter(void);
205 int       ppsratecheck(struct timeval *, int *, int);
206 int       ratecheck(struct timeval *, const struct timeval *);
207 int       settime(struct proc *p, struct timespec *);
208 int       nanosleep1(struct lwp *, clockid_t, int, struct timespec *,
209               struct timespec *);
210 int       settimeofday1(const struct timeval *, bool,
211               const void *, struct lwp *, bool);
212 int       timer_create1(timer_t *, clockid_t, struct sigevent *, copyin_t,
213               struct lwp *);
214 int       inittimeleft(struct timespec *, struct timespec *);
215 int       gettimeleft(struct timespec *, struct timespec *);
216 void      timerupcall(struct lwp *);
217 void      time_init(void);
218 bool      time_wraps(struct timespec *, struct timespec *);
219 
220 void      itimer_init(struct itimer *, const struct itimer_ops *,
221               clockid_t, struct itlist *);
222 void      itimer_poison(struct itimer *);
223 void      itimer_fini(struct itimer *);
224 
225 void      itimer_lock(void);
226 void      itimer_unlock(void);
227 bool      itimer_lock_held(void);                 /* for diagnostic assertions only */
228 int       itimer_settime(struct itimer *);
229 void      itimer_gettime(const struct itimer *, struct itimerspec *);
230 
231 void      ptimer_tick(struct lwp *, bool);
232 void      ptimers_free(struct proc *, int);
233 
234 #define   time_second         getrealtime()
235 #define   time_uptime         getuptime()
236 #define   time_uptime32       getuptime32()
237 
238 #ifdef __HAVE_ATOMIC64_LOADSTORE
239 
240 extern volatile time_t time__second;    /* current second in the epoch */
241 extern volatile time_t time__uptime;    /* system uptime in seconds */
242 
243 static inline time_t
getrealtime(void)244 getrealtime(void)
245 {
246           return atomic_load_relaxed(&time__second);
247 }
248 
249 static inline time_t
getuptime(void)250 getuptime(void)
251 {
252           return atomic_load_relaxed(&time__uptime);
253 }
254 
255 static inline time_t
getboottime(void)256 getboottime(void)
257 {
258           return getrealtime() - getuptime();
259 }
260 
261 static inline uint32_t
getuptime32(void)262 getuptime32(void)
263 {
264           return getuptime() & 0xffffffff;
265 }
266 
267 #else
268 
269 time_t              getrealtime(void);
270 time_t              getuptime(void);
271 time_t              getboottime(void);
272 uint32_t  getuptime32(void);
273 
274 #endif
275 
276 extern int time_adjusted;
277 
278 #define   DEFAULT_TIMEOUT_EPSILON                                                               \
279           (&(const struct bintime) {                                                  \
280                     .sec = 0,                                                         \
281                     .frac = ((uint64_t)1 << 32)/hz << 32,                             \
282           })
283 
time_mono_to_wall(time_t t)284 static __inline time_t time_mono_to_wall(time_t t)
285 {
286 
287           return t + getboottime();
288 }
289 
time_wall_to_mono(time_t t)290 static __inline time_t time_wall_to_mono(time_t t)
291 {
292 
293           return t - getboottime();
294 }
295 
296 #endif /* !_SYS_TIMEVAR_H_ */
297