2014/10/15 下午 10:11:14

iphone Programming Glossary: mach_absolute_time

What is mach_absolute_time based on on iPhone

http://stackoverflow.com/questions/1450737/what-is-mach-absolute-time-based-on-on-iphone

is mach_absolute_time based on on iPhone I use this code to keep track of last reboot float secondsSinceLastReboot return float mach_absolute_time.. based on on iPhone I use this code to keep track of last reboot float secondsSinceLastReboot return float mach_absolute_time float timebase.numer float timebase.denom 1000000000.0f I assumed mach_absolute_time was based on last device boot time.. return float mach_absolute_time float timebase.numer float timebase.denom 1000000000.0f I assumed mach_absolute_time was based on last device boot time like it is on a mac. It doesn't seem to be based on that. I actually have no idea what..

CoreAudio AudioTimeStamp.mHostTime clock frequency?

http://stackoverflow.com/questions/675626/coreaudio-audiotimestamp-mhosttime-clock-frequency

improve this question There exists the following file mach mach_time.h In this file you'll find a function named mach_absolute_time . mach_absolute_time returns an uint64 number that has no defined meaning. Imagine those are ticks but nowhere is defined.. There exists the following file mach mach_time.h In this file you'll find a function named mach_absolute_time . mach_absolute_time returns an uint64 number that has no defined meaning. Imagine those are ticks but nowhere is defined how long a single tick.. meaning. Imagine those are ticks but nowhere is defined how long a single tick is. Only four things are defined mach_absolute_time returns the number of ticks since the last boot. At every boot the tick counter starts at zero. The tick counter counts..

How can I locally detect iPhone clock advancement by a user between app runs?

http://stackoverflow.com/questions/7122216/how-can-i-locally-detect-iphone-clock-advancement-by-a-user-between-app-runs

that is not a requirement. iphone objective c ios clock anti cheat share improve this question CACurrentMediaTime mach_absolute_time Take a look at this questions iOS How to measure passed time independent of clock and time zone changes Calculating number.. of seconds between two points in time in Cocoa even when system clock has changed mid way CACurrentMediaTime uses mach_absolute_time http developer.apple.com library mac #documentation Cocoa Reference CoreAnimation_functions Reference reference.html Here.. http www.informit.com blogs blog.aspx b 02b4e309 308c 468a bab1 cebb1404be6a Here you have a more information on mach_absolute_time http developer.apple.com library mac #qa qa1398 _index.html http shiftedbits.org 2008 10 01 mach_absolute_time on the iphone..

Internal clock in iPhone background mode

http://stackoverflow.com/questions/9564823/internal-clock-in-iphone-background-mode

correct. When the device goes to sleep can happen sometime after it's locked the internal CPU clock stops ticking and mach_absolute_time won't update either. Theoretically it will return the exact same value if you call it right before the device went to sleep.. kern.boottime boottime size NULL 0 assert ret 0 return boottime.tv_sec Original incorrect answer You can use mach_absolute_time which isn't affected by date changes made by the user. When you book the ticket get the correct date from the server and.. affected by date changes made by the user. When you book the ticket get the correct date from the server and record mach_absolute_time . Now you will always be able to call mach_absolute_time whenever you want calculate the difference from the one you recorded..