/* * Copyright (c) 2016 Apple Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_HEADER_END@ */ #include <mach/mach_time.h> extern kern_return_t mach_timebase_info_trap(mach_timebase_info_t info); kern_return_t mach_timebase_info(mach_timebase_info_t info){ static mach_timebase_info_data_t cached_info; /* * This is racy, but because it is safe to initialize twice we avoid a * barrier in the fast path by risking double initialization. */ if (cached_info.numer == 0 || cached_info.denom == 0){ kern_return_t kr = mach_timebase_info_trap(&cached_info); if (kr != KERN_SUCCESS) return kr; } info->numer = cached_info.numer; info->denom = cached_info.denom; return KERN_SUCCESS; }