1 /* 2 * Copyright (c) 2018 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 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 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 /* 36 * UKP-Optimized gettimeofday(). Use the kpmap after the 10th call. 37 */ 38 #include <sys/cdefs.h> 39 #include <sys/types.h> 40 #include <sys/syscall.h> 41 #include <sys/upmap.h> 42 #include <sys/time.h> 43 #include <machine/cpufunc.h> 44 #include <errno.h> 45 #include <time.h> 46 #include <stdio.h> 47 #include <unistd.h> 48 /*#include "un-namespace.h"*/ 49 #include "libc_private.h" 50 #include "upmap.h" 51 52 extern int __sys_gettimeofday(struct timeval *, struct timezone *); 53 int __gettimeofday(struct timeval *, struct timezone *); 54 55 static int fast_clock; 56 static int fast_count; 57 static int *fast_gtod; 58 static int *upticksp; 59 static struct timespec *ts_realtime; 60 61 #ifdef KPTYPE_FAST_GTOD 62 int 63 __gettimeofday(struct timeval *tv, struct timezone *tz) 64 { 65 struct timespec ts; 66 int res; 67 int w; 68 69 if (fast_clock == 0 && fast_count++ >= 10) { 70 __kpmap_map(&upticksp, &fast_clock, KPTYPE_UPTICKS); 71 __kpmap_map(&ts_realtime, &fast_clock, KPTYPE_TS_REALTIME); 72 __kpmap_map(&fast_gtod, &fast_clock, KPTYPE_FAST_GTOD); 73 __kpmap_map(NULL, &fast_clock, 0); 74 } 75 if (fast_clock > 0 && *fast_gtod && tz == NULL) { 76 do { 77 w = *upticksp; 78 cpu_lfence(); 79 ts = ts_realtime[w & 1]; 80 cpu_lfence(); 81 w = *upticksp - w; 82 } while (w > 1); 83 res = 0; 84 if (tv) { 85 tv->tv_sec = ts.tv_sec; 86 tv->tv_usec = ts.tv_nsec / 1000; 87 } 88 } else { 89 res = __sys_gettimeofday(tv, tz); 90 } 91 return res; 92 } 93 94 #else 95 96 int 97 __gettimeofday(struct timeval *tv, struct timezone *tz) 98 { 99 int res; 100 101 res = __sys_gettimeofday(tv, tz); 102 return res; 103 } 104 105 #endif 106 107 __weak_reference(__gettimeofday, gettimeofday); 108