bsd/kern/kern_clock.c

   1 /*
   2  * Copyright (c) 2000-2018 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  29 /*-
  30  * Copyright (c) 1982, 1986, 1991, 1993
  31  *      The Regents of the University of California.  All rights reserved.
  32  * (c) UNIX System Laboratories, Inc.
  33  * All or some portions of this file are derived from material licensed
  34  * to the University of California by American Telephone and Telegraph
  35  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  36  * the permission of UNIX System Laboratories, Inc.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 3. All advertising materials mentioning features or use of this software
  47  *    must display the following acknowledgement:
  48  *      This product includes software developed by the University of
  49  *      California, Berkeley and its contributors.
  50  * 4. Neither the name of the University nor the names of its contributors
  51  *    may be used to endorse or promote products derived from this software
  52  *    without specific prior written permission.
  53  *
  54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  64  * SUCH DAMAGE.
  65  *
  66  *      @(#)kern_clock.c        8.5 (Berkeley) 1/21/94
  67  */
  68 /*
  69  * HISTORY
  70  */
  71
  72 #include <sys/param.h>
  73 #include <sys/systm.h>
  74 #include <sys/time.h>
  75 #include <sys/resourcevar.h>
  76 #include <sys/kernel.h>
  77 #include <sys/resource.h>
  78 #include <sys/proc_internal.h>
  79 #include <sys/vm.h>
  80 #include <sys/sysctl.h>
  81
  82 #include <kern/thread.h>
  83 #include <kern/ast.h>
  84 #include <kern/assert.h>
  85 #include <mach/boolean.h>
  86
  87 #include <kern/thread_call.h>
  88
  89 void bsd_uprofil(struct time_value *syst, user_addr_t pc);
  90 int tvtohz(struct timeval *tv);
  91
  92 /*
  93  * Clock handling routines.
  94  *
  95  * This code is written to operate with two timers which run
  96  * independently of each other. The main clock, running at hz
  97  * times per second, is used to do scheduling and timeout calculations.
  98  * The second timer does resource utilization estimation statistically
  99  * based on the state of the machine phz times a second. Both functions
 100  * can be performed by a single clock (ie hz == phz), however the
 101  * statistics will be much more prone to errors. Ideally a machine
 102  * would have separate clocks measuring time spent in user state, system
 103  * state, interrupt state, and idle state. These clocks would allow a non-
 104  * approximate measure of resource utilization.
 105  */
 106
 107 /*
 108  * The hz hardware interval timer.
 109  */
 110
 111 int             hz = 100;                /* GET RID OF THIS !!! */
 112 int             tick = (1000000 / 100);  /* GET RID OF THIS !!! */
 113
 114 /*
 115  * Kernel timeout services.
 116  */
 117
 118 /*
 119  *      Set a timeout.
 120  *
 121  *      fcn:            function to call
 122  *      param:          parameter to pass to function
 123  *      interval:       timeout interval, in hz.
 124  */
 125 void
 126 timeout(
 127         timeout_fcn_t                   fcn,
 128         void                                    *param,
 129         int                                             interval)
 130 {
 131         uint64_t                deadline;
 132
 133         clock_interval_to_deadline(interval, NSEC_PER_SEC / hz, &deadline);
 134         thread_call_func_delayed((thread_call_func_t)fcn, param, deadline);
 135 }
 136
 137 /*
 138  *      Set a timeout with leeway.
 139  *
 140  *      fcn:            function to call
 141  *      param:          parameter to pass to function
 142  *      interval:       timeout interval, in hz.
 143  *      leeway_interval:        leeway interval, in hz.
 144  */
 145 void
 146 timeout_with_leeway(
 147         timeout_fcn_t                   fcn,
 148         void                                    *param,
 149         int                                             interval,
 150         int                                             leeway_interval)
 151 {
 152         uint64_t                deadline;
 153         uint64_t                leeway;
 154
 155         clock_interval_to_deadline(interval, NSEC_PER_SEC / hz, &deadline);
 156
 157         clock_interval_to_absolutetime_interval(leeway_interval, NSEC_PER_SEC / hz, &leeway);
 158
 159         thread_call_func_delayed_with_leeway((thread_call_func_t)fcn, param, deadline, leeway, THREAD_CALL_DELAY_LEEWAY);
 160 }
 161
 162 /*
 163  * Cancel a timeout.
 164  * Deprecated because it's very inefficient.
 165  * Switch to an allocated thread call instead.
 166  */
 167 void
 168 untimeout(
 169         timeout_fcn_t           fcn,
 170         void                    *param)
 171 {
 172         thread_call_func_cancel((thread_call_func_t)fcn, param, FALSE);
 173 }
 174
 175
 176 /*
 177  *      Set a timeout.
 178  *
 179  *      fcn:            function to call
 180  *      param:          parameter to pass to function
 181  *      ts:             timeout interval, in timespec
 182  */
 183 void
 184 bsd_timeout(
 185         timeout_fcn_t                   fcn,
 186         void                                    *param,
 187         struct timespec         *ts)
 188 {
 189         uint64_t                deadline = 0;
 190
 191         if (ts && (ts->tv_sec || ts->tv_nsec)) {
 192                 nanoseconds_to_absolutetime((uint64_t)ts->tv_sec * NSEC_PER_SEC + ts->tv_nsec, &deadline );
 193                 clock_absolutetime_interval_to_deadline( deadline, &deadline );
 194         }
 195         thread_call_func_delayed((thread_call_func_t)fcn, param, deadline);
 196 }
 197
 198 /*
 199  * Cancel a timeout.
 200  * Deprecated because it's very inefficient.
 201  * Switch to an allocated thread call instead.
 202  */
 203 void
 204 bsd_untimeout(
 205         timeout_fcn_t           fcn,
 206         void                    *param)
 207 {
 208         thread_call_func_cancel((thread_call_func_t)fcn, param, FALSE);
 209 }
 210
 211
 212 /*
 213  * Compute number of hz until specified time.
 214  * Used to compute third argument to timeout() from an
 215  * absolute time.
 216  */
 217 int
 218 hzto(struct timeval *tv)
 219 {
 220         struct timeval now;
 221         long ticks;
 222         long sec;
 223
 224         microtime(&now);
 225         /*
 226          * If number of milliseconds will fit in 32 bit arithmetic,
 227          * then compute number of milliseconds to time and scale to
 228          * ticks.  Otherwise just compute number of hz in time, rounding
 229          * times greater than representible to maximum value.
 230          *
 231          * Delta times less than 25 days can be computed ``exactly''.
 232          * Maximum value for any timeout in 10ms ticks is 250 days.
 233          */
 234         sec = tv->tv_sec - now.tv_sec;
 235         if (sec <= 0x7fffffff / 1000 - 1000) {
 236                 ticks = ((tv->tv_sec - now.tv_sec) * 1000 +
 237                     (tv->tv_usec - now.tv_usec) / 1000)
 238                     / (tick / 1000);
 239         } else if (sec <= 0x7fffffff / hz) {
 240                 ticks = sec * hz;
 241         } else {
 242                 ticks = 0x7fffffff;
 243         }
 244
 245         return ticks;
 246 }
 247
 248 /*
 249  * Return information about system clocks.
 250  */
 251 static int
 252 sysctl_clockrate
 253 (__unused struct sysctl_oid *oidp, __unused void *arg1, __unused int arg2, __unused struct sysctl_req *req)
 254 {
 255         struct clockinfo clkinfo = {
 256                 .hz         = hz,
 257                 .tick       = tick,
 258                 .tickadj    = 0,
 259                 .stathz     = hz,
 260                 .profhz     = hz,
 261         };
 262
 263         return sysctl_io_opaque(req, &clkinfo, sizeof(clkinfo), NULL);
 264 }
 265
 266 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate,
 267     CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED,
 268     0, 0, sysctl_clockrate, "S,clockinfo", "");
 269
 270
 271 /*
 272  * Compute number of ticks in the specified amount of time.
 273  */
 274 int
 275 tvtohz(struct timeval *tv)
 276 {
 277         unsigned long ticks;
 278         long sec, usec;
 279
 280         /*
 281          * If the number of usecs in the whole seconds part of the time
 282          * difference fits in a long, then the total number of usecs will
 283          * fit in an unsigned long.  Compute the total and convert it to
 284          * ticks, rounding up and adding 1 to allow for the current tick
 285          * to expire.  Rounding also depends on unsigned long arithmetic
 286          * to avoid overflow.
 287          *
 288          * Otherwise, if the number of ticks in the whole seconds part of
 289          * the time difference fits in a long, then convert the parts to
 290          * ticks separately and add, using similar rounding methods and
 291          * overflow avoidance.  This method would work in the previous
 292          * case but it is slightly slower and assumes that hz is integral.
 293          *
 294          * Otherwise, round the time difference down to the maximum
 295          * representable value.
 296          *
 297          * If ints have 32 bits, then the maximum value for any timeout in
 298          * 10ms ticks is 248 days.
 299          */
 300         sec = tv->tv_sec;
 301         usec = tv->tv_usec;
 302         if (usec < 0) {
 303                 sec--;
 304                 usec += 1000000;
 305         }
 306         if (sec < 0) {
 307 #ifdef DIAGNOSTIC
 308                 if (usec > 0) {
 309                         sec++;
 310                         usec -= 1000000;
 311                 }
 312                 printf("tvotohz: negative time difference %ld sec %ld usec\n",
 313                     sec, usec);
 314 #endif
 315                 ticks = 1;
 316         } else if (sec <= LONG_MAX / 1000000) {
 317                 ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1))
 318                     / tick + 1;
 319         } else if (sec <= LONG_MAX / hz) {
 320                 ticks = sec * hz
 321                     + ((unsigned long)usec + (tick - 1)) / tick + 1;
 322         } else {
 323                 ticks = LONG_MAX;
 324         }
 325         if (ticks > INT_MAX) {
 326                 ticks = INT_MAX;
 327         }
 328         return (int)ticks;
 329 }
 330
 331 /* TBD locking user profiling is not resolved yet */
 332 void
 333 get_procrustime(time_value_t *tv)
 334 {
 335         struct proc *p = current_proc();
 336         struct timeval st;
 337
 338         if (p == NULL) {
 339                 return;
 340         }
 341         if (!(p->p_flag & P_PROFIL)) {
 342                 return;
 343         }
 344
 345         //proc_lock(p);
 346         st = p->p_stats->p_ru.ru_stime;
 347         //proc_unlock(p);
 348
 349         tv->seconds = st.tv_sec;
 350         tv->microseconds = st.tv_usec;
 351 }