Commit | Line | Data |
---|---|---|
747d2bea | 1 | /* kern_time.c 6.2 84/06/06 */ |
961945a8 SL |
2 | |
3 | #include "../machine/reg.h" | |
aac7ea5b BJ |
4 | |
5 | #include "../h/param.h" | |
b6f30e0a | 6 | #include "../h/dir.h" /* XXX */ |
aac7ea5b | 7 | #include "../h/user.h" |
b6f30e0a | 8 | #include "../h/kernel.h" |
aac7ea5b BJ |
9 | #include "../h/inode.h" |
10 | #include "../h/proc.h" | |
b6f30e0a | 11 | |
1edb1cf8 BJ |
12 | /* |
13 | * Time of day and interval timer support. | |
aa261505 BJ |
14 | * |
15 | * These routines provide the kernel entry points to get and set | |
16 | * the time-of-day and per-process interval timers. Subroutines | |
17 | * here provide support for adding and subtracting timeval structures | |
18 | * and decrementing interval timers, optionally reloading the interval | |
19 | * timers when they expire. | |
1edb1cf8 BJ |
20 | */ |
21 | ||
b6f30e0a | 22 | gettimeofday() |
4147b3f6 | 23 | { |
b6f30e0a BJ |
24 | register struct a { |
25 | struct timeval *tp; | |
26 | struct timezone *tzp; | |
27 | } *uap = (struct a *)u.u_ap; | |
28 | struct timeval atv; | |
1edb1cf8 | 29 | int s; |
4147b3f6 | 30 | |
1edb1cf8 | 31 | s = spl7(); atv = time; splx(s); |
127f7d76 SL |
32 | u.u_error = copyout((caddr_t)&atv, (caddr_t)uap->tp, sizeof (atv)); |
33 | if (u.u_error) | |
b6f30e0a | 34 | return; |
b6f30e0a BJ |
35 | if (uap->tzp == 0) |
36 | return; | |
1edb1cf8 | 37 | /* SHOULD HAVE PER-PROCESS TIMEZONE */ |
127f7d76 | 38 | u.u_error = copyout((caddr_t)&tz, (caddr_t)uap->tzp, sizeof (tz)); |
4147b3f6 BJ |
39 | } |
40 | ||
b6f30e0a | 41 | settimeofday() |
aac7ea5b | 42 | { |
b6f30e0a | 43 | register struct a { |
1edb1cf8 BJ |
44 | struct timeval *tv; |
45 | struct timezone *tzp; | |
b6f30e0a BJ |
46 | } *uap = (struct a *)u.u_ap; |
47 | struct timeval atv; | |
48 | struct timezone atz; | |
4147b3f6 | 49 | |
127f7d76 SL |
50 | u.u_error = copyin((caddr_t)uap->tv, (caddr_t)&atv, |
51 | sizeof (struct timeval)); | |
52 | if (u.u_error) | |
b6f30e0a | 53 | return; |
1edb1cf8 BJ |
54 | setthetime(&atv); |
55 | if (uap->tzp && suser()) { | |
127f7d76 SL |
56 | u.u_error = copyin((caddr_t)uap->tzp, (caddr_t)&atz, |
57 | sizeof (atz)); | |
747d2bea SL |
58 | if (u.u_error == 0) |
59 | tz = atz; | |
b6f30e0a | 60 | } |
4147b3f6 BJ |
61 | } |
62 | ||
1edb1cf8 BJ |
63 | setthetime(tv) |
64 | struct timeval *tv; | |
65 | { | |
1edb1cf8 BJ |
66 | int s; |
67 | ||
68 | if (!suser()) | |
69 | return; | |
aa261505 | 70 | /* WHAT DO WE DO ABOUT PENDING REAL-TIME TIMEOUTS??? */ |
1edb1cf8 BJ |
71 | boottime.tv_sec += tv->tv_sec - time.tv_sec; |
72 | s = spl7(); time = *tv; splx(s); | |
993113c5 | 73 | resettodr(); |
1edb1cf8 BJ |
74 | } |
75 | ||
aa261505 BJ |
76 | /* |
77 | * Get value of an interval timer. The process virtual and | |
78 | * profiling virtual time timers are kept in the u. area, since | |
79 | * they can be swapped out. These are kept internally in the | |
80 | * way they are specified externally: in time until they expire. | |
81 | * | |
82 | * The real time interval timer is kept in the process table slot | |
83 | * for the process, and its value (it_value) is kept as an | |
84 | * absolute time rather than as a delta, so that it is easy to keep | |
85 | * periodic real-time signals from drifting. | |
86 | * | |
87 | * Virtual time timers are processed in the hardclock() routine of | |
88 | * kern_clock.c. The real time timer is processed by a timeout | |
89 | * routine, called from the softclock() routine. Since a callout | |
90 | * may be delayed in real time due to interrupt processing in the system, | |
91 | * it is possible for the real time timeout routine (realitexpire, given below), | |
92 | * to be delayed in real time past when it is supposed to occur. It | |
93 | * does not suffice, therefore, to reload the real timer .it_value from the | |
94 | * real time timers .it_interval. Rather, we compute the next time in | |
95 | * absolute time the timer should go off. | |
96 | */ | |
b6f30e0a | 97 | getitimer() |
aac7ea5b BJ |
98 | { |
99 | register struct a { | |
b6f30e0a BJ |
100 | u_int which; |
101 | struct itimerval *itv; | |
102 | } *uap = (struct a *)u.u_ap; | |
d01b68d6 | 103 | struct itimerval aitv; |
b6f30e0a | 104 | int s; |
aac7ea5b | 105 | |
b6f30e0a BJ |
106 | if (uap->which > 2) { |
107 | u.u_error = EINVAL; | |
108 | return; | |
aac7ea5b | 109 | } |
b6f30e0a | 110 | s = spl7(); |
d01b68d6 | 111 | if (uap->which == ITIMER_REAL) { |
aa261505 BJ |
112 | /* |
113 | * Convert from absoulte to relative time in .it_value | |
114 | * part of real time timer. If time for real time timer | |
115 | * has passed return 0, else return difference between | |
116 | * current time and time for the timer to go off. | |
117 | */ | |
d01b68d6 BJ |
118 | aitv = u.u_procp->p_realtimer; |
119 | if (timerisset(&aitv.it_value)) | |
120 | if (timercmp(&aitv.it_value, &time, <)) | |
121 | timerclear(&aitv.it_value); | |
122 | else | |
123 | timevalsub(&aitv.it_value, &time); | |
124 | } else | |
125 | aitv = u.u_timer[uap->which]; | |
126 | splx(s); | |
127f7d76 SL |
127 | u.u_error = copyout((caddr_t)&aitv, (caddr_t)uap->itv, |
128 | sizeof (struct itimerval)); | |
b6f30e0a | 129 | splx(s); |
aac7ea5b BJ |
130 | } |
131 | ||
b6f30e0a | 132 | setitimer() |
aac7ea5b BJ |
133 | { |
134 | register struct a { | |
b6f30e0a | 135 | u_int which; |
1edb1cf8 | 136 | struct itimerval *itv, *oitv; |
b6f30e0a BJ |
137 | } *uap = (struct a *)u.u_ap; |
138 | struct itimerval aitv; | |
139 | int s; | |
d01b68d6 | 140 | register struct proc *p = u.u_procp; |
aac7ea5b | 141 | |
b6f30e0a BJ |
142 | if (uap->which > 2) { |
143 | u.u_error = EINVAL; | |
1edb1cf8 | 144 | return; |
b6f30e0a | 145 | } |
127f7d76 SL |
146 | u.u_error = copyin((caddr_t)uap->itv, (caddr_t)&aitv, |
147 | sizeof (struct itimerval)); | |
148 | if (u.u_error) | |
1edb1cf8 | 149 | return; |
1edb1cf8 BJ |
150 | if (uap->oitv) { |
151 | uap->itv = uap->oitv; | |
152 | getitimer(); | |
b6f30e0a | 153 | } |
1edb1cf8 BJ |
154 | if (itimerfix(&aitv.it_value) || itimerfix(&aitv.it_interval)) { |
155 | u.u_error = EINVAL; | |
156 | return; | |
157 | } | |
158 | s = spl7(); | |
d01b68d6 | 159 | if (uap->which == ITIMER_REAL) { |
b32450f4 | 160 | untimeout(realitexpire, (caddr_t)p); |
d01b68d6 BJ |
161 | if (timerisset(&aitv.it_value)) { |
162 | timevaladd(&aitv.it_value, &time); | |
b32450f4 | 163 | timeout(realitexpire, (caddr_t)p, hzto(&aitv.it_value)); |
d01b68d6 BJ |
164 | } |
165 | p->p_realtimer = aitv; | |
166 | } else | |
1edb1cf8 | 167 | u.u_timer[uap->which] = aitv; |
b6f30e0a | 168 | splx(s); |
b6f30e0a BJ |
169 | } |
170 | ||
aa261505 BJ |
171 | /* |
172 | * Real interval timer expired: | |
173 | * send process whose timer expired an alarm signal. | |
174 | * If time is not set up to reload, then just return. | |
175 | * Else compute next time timer should go off which is > current time. | |
176 | * This is where delay in processing this timeout causes multiple | |
177 | * SIGALRM calls to be compressed into one. | |
178 | */ | |
179 | realitexpire(p) | |
d01b68d6 BJ |
180 | register struct proc *p; |
181 | { | |
182 | int s; | |
183 | ||
184 | psignal(p, SIGALRM); | |
185 | if (!timerisset(&p->p_realtimer.it_interval)) { | |
186 | timerclear(&p->p_realtimer.it_value); | |
187 | return; | |
188 | } | |
189 | for (;;) { | |
190 | s = spl7(); | |
191 | timevaladd(&p->p_realtimer.it_value, | |
192 | &p->p_realtimer.it_interval); | |
193 | if (timercmp(&p->p_realtimer.it_value, &time, >)) { | |
b32450f4 BJ |
194 | timeout(realitexpire, (caddr_t)p, |
195 | hzto(&p->p_realtimer.it_value)); | |
d01b68d6 BJ |
196 | splx(s); |
197 | return; | |
198 | } | |
199 | splx(s); | |
200 | } | |
201 | } | |
202 | ||
aa261505 BJ |
203 | /* |
204 | * Check that a proposed value to load into the .it_value or | |
205 | * .it_interval part of an interval timer is acceptable, and | |
206 | * fix it to have at least minimal value (i.e. if it is less | |
207 | * than the resolution of the clock, round it up.) | |
208 | */ | |
1edb1cf8 BJ |
209 | itimerfix(tv) |
210 | struct timeval *tv; | |
b6f30e0a | 211 | { |
b6f30e0a | 212 | |
d01b68d6 BJ |
213 | if (tv->tv_sec < 0 || tv->tv_sec > 100000000 || |
214 | tv->tv_usec < 0 || tv->tv_usec >= 1000000) | |
1edb1cf8 | 215 | return (EINVAL); |
c45fcba6 | 216 | if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) |
1edb1cf8 BJ |
217 | tv->tv_usec = tick; |
218 | return (0); | |
b6f30e0a BJ |
219 | } |
220 | ||
aa261505 BJ |
221 | /* |
222 | * Decrement an interval timer by a specified number | |
223 | * of microseconds, which must be less than a second, | |
224 | * i.e. < 1000000. If the timer expires, then reload | |
225 | * it. In this case, carry over (usec - old value) to | |
226 | * reducint the value reloaded into the timer so that | |
227 | * the timer does not drift. This routine assumes | |
228 | * that it is called in a context where the timers | |
229 | * on which it is operating cannot change in value. | |
230 | */ | |
b6f30e0a BJ |
231 | itimerdecr(itp, usec) |
232 | register struct itimerval *itp; | |
233 | int usec; | |
234 | { | |
235 | ||
1edb1cf8 BJ |
236 | if (itp->it_value.tv_usec < usec) { |
237 | if (itp->it_value.tv_sec == 0) { | |
aa261505 | 238 | /* expired, and already in next interval */ |
1edb1cf8 | 239 | usec -= itp->it_value.tv_usec; |
b6f30e0a | 240 | goto expire; |
1edb1cf8 BJ |
241 | } |
242 | itp->it_value.tv_usec += 1000000; | |
243 | itp->it_value.tv_sec--; | |
aac7ea5b | 244 | } |
1edb1cf8 BJ |
245 | itp->it_value.tv_usec -= usec; |
246 | usec = 0; | |
247 | if (timerisset(&itp->it_value)) | |
b6f30e0a | 248 | return (1); |
aa261505 | 249 | /* expired, exactly at end of interval */ |
b6f30e0a | 250 | expire: |
1edb1cf8 BJ |
251 | if (timerisset(&itp->it_interval)) { |
252 | itp->it_value = itp->it_interval; | |
253 | itp->it_value.tv_usec -= usec; | |
254 | if (itp->it_value.tv_usec < 0) { | |
255 | itp->it_value.tv_usec += 1000000; | |
256 | itp->it_value.tv_sec--; | |
257 | } | |
258 | } else | |
aa261505 | 259 | itp->it_value.tv_usec = 0; /* sec is already 0 */ |
b6f30e0a | 260 | return (0); |
aac7ea5b BJ |
261 | } |
262 | ||
aa261505 BJ |
263 | /* |
264 | * Add and subtract routines for timevals. | |
265 | * N.B.: subtract routine doesn't deal with | |
266 | * results which are before the beginning, | |
267 | * it just gets very confused in this case. | |
268 | * Caveat emptor. | |
269 | */ | |
270 | timevaladd(t1, t2) | |
271 | struct timeval *t1, *t2; | |
272 | { | |
273 | ||
274 | t1->tv_sec += t2->tv_sec; | |
275 | t1->tv_usec += t2->tv_usec; | |
276 | timevalfix(t1); | |
277 | } | |
278 | ||
279 | timevalsub(t1, t2) | |
280 | struct timeval *t1, *t2; | |
281 | { | |
282 | ||
283 | t1->tv_sec -= t2->tv_sec; | |
284 | t1->tv_usec -= t2->tv_usec; | |
285 | timevalfix(t1); | |
286 | } | |
287 | ||
288 | timevalfix(t1) | |
289 | struct timeval *t1; | |
290 | { | |
291 | ||
292 | if (t1->tv_usec < 0) { | |
293 | t1->tv_sec--; | |
294 | t1->tv_usec += 1000000; | |
295 | } | |
296 | if (t1->tv_usec >= 1000000) { | |
297 | t1->tv_sec++; | |
298 | t1->tv_usec -= 1000000; | |
299 | } | |
300 | } |