1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <sys/types.h> 30 #include <time.h> 31 #include <errno.h> 32 33 /* 34 * This function is blatently stolen from the kernel. 35 * See the dissertation in the comments preceding the 36 * hrt2ts() function in: 37 * uts/common/os/timers.c 38 */ 39 void 40 hrt2ts(hrtime_t hrt, timespec_t *tsp) 41 { 42 uint32_t sec, nsec, tmp; 43 44 tmp = (uint32_t)(hrt >> 30); 45 sec = tmp - (tmp >> 2); 46 sec = tmp - (sec >> 5); 47 sec = tmp + (sec >> 1); 48 sec = tmp - (sec >> 6) + 7; 49 sec = tmp - (sec >> 3); 50 sec = tmp + (sec >> 1); 51 sec = tmp + (sec >> 3); 52 sec = tmp + (sec >> 4); 53 tmp = (sec << 7) - sec - sec - sec; 54 tmp = (tmp << 7) - tmp - tmp - tmp; 55 tmp = (tmp << 7) - tmp - tmp - tmp; 56 nsec = (uint32_t)hrt - (tmp << 9); 57 while (nsec >= NANOSEC) { 58 nsec -= NANOSEC; 59 sec++; 60 } 61 tsp->tv_sec = (time_t)sec; 62 tsp->tv_nsec = nsec; 63 } 64 65 /* 66 * Convert absolute time to relative time. 67 * All *timedwait() system call traps expect relative time. 68 */ 69 void 70 abstime_to_reltime(clockid_t clock_id, 71 const timespec_t *abstime, timespec_t *reltime) 72 { 73 extern int __clock_gettime(clockid_t, timespec_t *); 74 timespec_t now; 75 76 if (clock_id == CLOCK_HIGHRES) 77 hrt2ts(gethrtime(), &now); 78 else 79 (void) __clock_gettime(clock_id, &now); 80 if (abstime->tv_nsec >= now.tv_nsec) { 81 reltime->tv_sec = abstime->tv_sec - now.tv_sec; 82 reltime->tv_nsec = abstime->tv_nsec - now.tv_nsec; 83 } else { 84 reltime->tv_sec = abstime->tv_sec - now.tv_sec - 1; 85 reltime->tv_nsec = abstime->tv_nsec - now.tv_nsec + NANOSEC; 86 } 87 /* 88 * If the absolute time has already passed, 89 * just set the relative time to zero. 90 */ 91 if (reltime->tv_sec < 0) { 92 reltime->tv_sec = 0; 93 reltime->tv_nsec = 0; 94 } 95 /* 96 * If the specified absolute time has a bad nanoseconds value, 97 * assign it to the relative time value. If the interface 98 * attempts to sleep, the bad value will be detected then. 99 * The SUSV3 Posix spec is very clear that such detection 100 * should not happen until an attempt to sleep is made. 101 */ 102 if ((ulong_t)abstime->tv_nsec >= NANOSEC) 103 reltime->tv_nsec = abstime->tv_nsec; 104 } 105