Cocoa 3D Tutorial Code

/*
 *  timing.h
 *
 *  Created by Paolo on 06/07/2007.
 *  Copyright 2010 Paolo Manna All rights reserved.
 *
 */

#include <mach/mach.h>
#include <mach/mach_time.h>
#include <unistd.h>

static mach_timebase_info_data_t	timebase	= {0, 0};

inline static uint64_t nanosecs()
{
	if (timebase.denom == 0)
		mach_timebase_info(&timebase);
	
	return (mach_absolute_time() * (uint64_t)(timebase.numer)) / (uint64_t)(timebase.denom);
}

inline static uint64_t usecs()
{
	if (timebase.denom == 0)
		mach_timebase_info(&timebase);
	
	return (mach_absolute_time() * (uint64_t)(timebase.numer) + 500ULL) / ((uint64_t)(timebase.denom) * 1000ULL);
}

inline static uint64_t msecs()
{
	if (timebase.denom == 0)
		mach_timebase_info(&timebase);
	
	return (mach_absolute_time() * (uint64_t)(timebase.numer) + 500000ULL) / ((uint64_t)(timebase.denom) * 1000000ULL);
}