subr_time.c revision 1.1.10.4
1 1.1.10.4 yamt /* $NetBSD: subr_time.c,v 1.1.10.4 2008/01/21 09:46:22 yamt Exp $ */ 2 1.1.10.2 yamt 3 1.1.10.2 yamt /* 4 1.1.10.2 yamt * Copyright (c) 1982, 1986, 1989, 1993 5 1.1.10.2 yamt * The Regents of the University of California. All rights reserved. 6 1.1.10.2 yamt * 7 1.1.10.2 yamt * Redistribution and use in source and binary forms, with or without 8 1.1.10.2 yamt * modification, are permitted provided that the following conditions 9 1.1.10.2 yamt * are met: 10 1.1.10.2 yamt * 1. Redistributions of source code must retain the above copyright 11 1.1.10.2 yamt * notice, this list of conditions and the following disclaimer. 12 1.1.10.2 yamt * 2. Redistributions in binary form must reproduce the above copyright 13 1.1.10.2 yamt * notice, this list of conditions and the following disclaimer in the 14 1.1.10.2 yamt * documentation and/or other materials provided with the distribution. 15 1.1.10.2 yamt * 3. Neither the name of the University nor the names of its contributors 16 1.1.10.2 yamt * may be used to endorse or promote products derived from this software 17 1.1.10.2 yamt * without specific prior written permission. 18 1.1.10.2 yamt * 19 1.1.10.2 yamt * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 1.1.10.2 yamt * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 1.1.10.2 yamt * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 1.1.10.2 yamt * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 1.1.10.2 yamt * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 1.1.10.2 yamt * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 1.1.10.2 yamt * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 1.1.10.2 yamt * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 1.1.10.2 yamt * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 1.1.10.2 yamt * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 1.1.10.2 yamt * SUCH DAMAGE. 30 1.1.10.2 yamt * 31 1.1.10.2 yamt * @(#)kern_clock.c 8.5 (Berkeley) 1/21/94 32 1.1.10.2 yamt * @(#)kern_time.c 8.4 (Berkeley) 5/26/95 33 1.1.10.2 yamt */ 34 1.1.10.2 yamt 35 1.1.10.2 yamt #include <sys/cdefs.h> 36 1.1.10.4 yamt __KERNEL_RCSID(0, "$NetBSD: subr_time.c,v 1.1.10.4 2008/01/21 09:46:22 yamt Exp $"); 37 1.1.10.2 yamt 38 1.1.10.2 yamt #include <sys/param.h> 39 1.1.10.2 yamt #include <sys/kernel.h> 40 1.1.10.2 yamt #include <sys/timex.h> 41 1.1.10.2 yamt #include <sys/time.h> 42 1.1.10.2 yamt #include <sys/timetc.h> 43 1.1.10.3 yamt #include <sys/intr.h> 44 1.1.10.2 yamt 45 1.1.10.2 yamt /* 46 1.1.10.2 yamt * Compute number of hz until specified time. Used to compute second 47 1.1.10.2 yamt * argument to callout_reset() from an absolute time. 48 1.1.10.2 yamt */ 49 1.1.10.2 yamt int 50 1.1.10.2 yamt hzto(struct timeval *tvp) 51 1.1.10.2 yamt { 52 1.1.10.2 yamt struct timeval now, tv; 53 1.1.10.2 yamt 54 1.1.10.2 yamt tv = *tvp; /* Don't modify original tvp. */ 55 1.1.10.2 yamt getmicrotime(&now); 56 1.1.10.2 yamt timersub(&tv, &now, &tv); 57 1.1.10.2 yamt return tvtohz(&tv); 58 1.1.10.2 yamt } 59 1.1.10.2 yamt 60 1.1.10.2 yamt /* 61 1.1.10.2 yamt * Compute number of ticks in the specified amount of time. 62 1.1.10.2 yamt */ 63 1.1.10.2 yamt int 64 1.1.10.2 yamt tvtohz(struct timeval *tv) 65 1.1.10.2 yamt { 66 1.1.10.2 yamt unsigned long ticks; 67 1.1.10.2 yamt long sec, usec; 68 1.1.10.2 yamt 69 1.1.10.2 yamt /* 70 1.1.10.2 yamt * If the number of usecs in the whole seconds part of the time 71 1.1.10.2 yamt * difference fits in a long, then the total number of usecs will 72 1.1.10.2 yamt * fit in an unsigned long. Compute the total and convert it to 73 1.1.10.2 yamt * ticks, rounding up and adding 1 to allow for the current tick 74 1.1.10.2 yamt * to expire. Rounding also depends on unsigned long arithmetic 75 1.1.10.2 yamt * to avoid overflow. 76 1.1.10.2 yamt * 77 1.1.10.2 yamt * Otherwise, if the number of ticks in the whole seconds part of 78 1.1.10.2 yamt * the time difference fits in a long, then convert the parts to 79 1.1.10.2 yamt * ticks separately and add, using similar rounding methods and 80 1.1.10.2 yamt * overflow avoidance. This method would work in the previous 81 1.1.10.2 yamt * case, but it is slightly slower and assumes that hz is integral. 82 1.1.10.2 yamt * 83 1.1.10.2 yamt * Otherwise, round the time difference down to the maximum 84 1.1.10.2 yamt * representable value. 85 1.1.10.2 yamt * 86 1.1.10.2 yamt * If ints are 32-bit, then the maximum value for any timeout in 87 1.1.10.2 yamt * 10ms ticks is 248 days. 88 1.1.10.2 yamt */ 89 1.1.10.2 yamt sec = tv->tv_sec; 90 1.1.10.2 yamt usec = tv->tv_usec; 91 1.1.10.2 yamt 92 1.1.10.2 yamt if (usec < 0) { 93 1.1.10.2 yamt sec--; 94 1.1.10.2 yamt usec += 1000000; 95 1.1.10.2 yamt } 96 1.1.10.2 yamt 97 1.1.10.2 yamt if (sec < 0 || (sec == 0 && usec <= 0)) { 98 1.1.10.2 yamt /* 99 1.1.10.2 yamt * Would expire now or in the past. Return 0 ticks. 100 1.1.10.2 yamt * This is different from the legacy hzto() interface, 101 1.1.10.2 yamt * and callers need to check for it. 102 1.1.10.2 yamt */ 103 1.1.10.2 yamt ticks = 0; 104 1.1.10.2 yamt } else if (sec <= (LONG_MAX / 1000000)) 105 1.1.10.2 yamt ticks = (((sec * 1000000) + (unsigned long)usec + (tick - 1)) 106 1.1.10.2 yamt / tick) + 1; 107 1.1.10.2 yamt else if (sec <= (LONG_MAX / hz)) 108 1.1.10.2 yamt ticks = (sec * hz) + 109 1.1.10.2 yamt (((unsigned long)usec + (tick - 1)) / tick) + 1; 110 1.1.10.2 yamt else 111 1.1.10.2 yamt ticks = LONG_MAX; 112 1.1.10.2 yamt 113 1.1.10.2 yamt if (ticks > INT_MAX) 114 1.1.10.2 yamt ticks = INT_MAX; 115 1.1.10.2 yamt 116 1.1.10.2 yamt return ((int)ticks); 117 1.1.10.2 yamt } 118 1.1.10.2 yamt 119 1.1.10.2 yamt /* 120 1.1.10.2 yamt * Compute number of ticks in the specified amount of time. 121 1.1.10.2 yamt */ 122 1.1.10.2 yamt int 123 1.1.10.2 yamt tstohz(struct timespec *ts) 124 1.1.10.2 yamt { 125 1.1.10.2 yamt struct timeval tv; 126 1.1.10.2 yamt 127 1.1.10.2 yamt /* 128 1.1.10.2 yamt * usec has great enough resolution for hz, so convert to a 129 1.1.10.2 yamt * timeval and use tvtohz() above. 130 1.1.10.2 yamt */ 131 1.1.10.2 yamt TIMESPEC_TO_TIMEVAL(&tv, ts); 132 1.1.10.2 yamt return tvtohz(&tv); 133 1.1.10.2 yamt } 134 1.1.10.2 yamt 135 1.1.10.2 yamt /* 136 1.1.10.2 yamt * Check that a proposed value to load into the .it_value or 137 1.1.10.2 yamt * .it_interval part of an interval timer is acceptable, and 138 1.1.10.2 yamt * fix it to have at least minimal value (i.e. if it is less 139 1.1.10.2 yamt * than the resolution of the clock, round it up.) 140 1.1.10.2 yamt */ 141 1.1.10.2 yamt int 142 1.1.10.2 yamt itimerfix(struct timeval *tv) 143 1.1.10.2 yamt { 144 1.1.10.2 yamt 145 1.1.10.2 yamt if (tv->tv_sec < 0 || tv->tv_usec < 0 || tv->tv_usec >= 1000000) 146 1.1.10.2 yamt return (EINVAL); 147 1.1.10.2 yamt if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) 148 1.1.10.2 yamt tv->tv_usec = tick; 149 1.1.10.2 yamt return (0); 150 1.1.10.2 yamt } 151 1.1.10.2 yamt 152 1.1.10.2 yamt int 153 1.1.10.2 yamt itimespecfix(struct timespec *ts) 154 1.1.10.2 yamt { 155 1.1.10.2 yamt 156 1.1.10.2 yamt if (ts->tv_sec < 0 || ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000) 157 1.1.10.2 yamt return (EINVAL); 158 1.1.10.2 yamt if (ts->tv_sec == 0 && ts->tv_nsec != 0 && ts->tv_nsec < tick * 1000) 159 1.1.10.2 yamt ts->tv_nsec = tick * 1000; 160 1.1.10.2 yamt return (0); 161 1.1.10.2 yamt } 162
Indexes created Mon Sep 29 21:09:56 GMT 2025