1*d4514f0bSApple OSS Distributions /* 2*d4514f0bSApple OSS Distributions * Copyright (c) 2016 Apple Inc. All rights reserved. 3*d4514f0bSApple OSS Distributions * 4*d4514f0bSApple OSS Distributions * @APPLE_LICENSE_HEADER_START@ 5*d4514f0bSApple OSS Distributions * 6*d4514f0bSApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code 7*d4514f0bSApple OSS Distributions * as defined in and that are subject to the Apple Public Source License 8*d4514f0bSApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in 9*d4514f0bSApple OSS Distributions * compliance with the License. Please obtain a copy of the License at 10*d4514f0bSApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this 11*d4514f0bSApple OSS Distributions * file. 12*d4514f0bSApple OSS Distributions * 13*d4514f0bSApple OSS Distributions * The Original Code and all software distributed under the License are 14*d4514f0bSApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 15*d4514f0bSApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 16*d4514f0bSApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 17*d4514f0bSApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 18*d4514f0bSApple OSS Distributions * Please see the License for the specific language governing rights and 19*d4514f0bSApple OSS Distributions * limitations under the License. 20*d4514f0bSApple OSS Distributions * 21*d4514f0bSApple OSS Distributions * @APPLE_LICENSE_HEADER_END@ 22*d4514f0bSApple OSS Distributions */ 23*d4514f0bSApple OSS Distributions #include <mach/mach_time.h> 24*d4514f0bSApple OSS Distributions 25*d4514f0bSApple OSS Distributions extern kern_return_t 26*d4514f0bSApple OSS Distributions mach_timebase_info_trap(mach_timebase_info_t info); 27*d4514f0bSApple OSS Distributions 28*d4514f0bSApple OSS Distributions kern_return_t mach_timebase_info(mach_timebase_info_t info)29*d4514f0bSApple OSS Distributionsmach_timebase_info(mach_timebase_info_t info) 30*d4514f0bSApple OSS Distributions { 31*d4514f0bSApple OSS Distributions static mach_timebase_info_data_t cached_info; 32*d4514f0bSApple OSS Distributions 33*d4514f0bSApple OSS Distributions /* 34*d4514f0bSApple OSS Distributions * This is racy, but because it is safe to initialize twice we avoid a 35*d4514f0bSApple OSS Distributions * barrier in the fast path by risking double initialization. 36*d4514f0bSApple OSS Distributions */ 37*d4514f0bSApple OSS Distributions if (cached_info.numer == 0 || cached_info.denom == 0) { 38*d4514f0bSApple OSS Distributions kern_return_t kr = mach_timebase_info_trap(&cached_info); 39*d4514f0bSApple OSS Distributions if (kr != KERN_SUCCESS) { 40*d4514f0bSApple OSS Distributions return kr; 41*d4514f0bSApple OSS Distributions } 42*d4514f0bSApple OSS Distributions } 43*d4514f0bSApple OSS Distributions 44*d4514f0bSApple OSS Distributions info->numer = cached_info.numer; 45*d4514f0bSApple OSS Distributions info->denom = cached_info.denom; 46*d4514f0bSApple OSS Distributions 47*d4514f0bSApple OSS Distributions return KERN_SUCCESS; 48*d4514f0bSApple OSS Distributions } 49