I sense that a few applications working on Apple Silicon will get this spectacularly incorrect
2021年2月23日Altering the appear Apple Silicon Macs
When something does not change for a long period of time we tend to obtain obsequious and reduced corners. For many years, the accuracy Mach appear Macs has ticked away in nanoseconds, and we have actually involved presume that it constantly will. When it’s contacted an entrance in the linked log, because the machTimestamp has actually always remained in split seconds, it’s very easy to presume that it is as well as compute time intervals appropriately.
Apple has actually alerted us that its brand-new Apple Silicon Macs will not be the same, and also continuing to make the presumption that Mach clock ticks occur as soon as every millisecond will show seriously incorrect. If any one of your code uses mach_absolute_time, or anything originated from it, consisting of the machTimestamp field in merged log essences, now is the moment to place your clock right.
As I have clarified formerly, Macs contain a number of different clocks as well as views of the time. Regional referral clocks and timers which currently work in appropriate time systems such as seconds aren’t affected by this change. It’s equipment clock ticks, Mach accuracy time, which alters. On Intel processors, that tick has actually been one split second long, so exercising a time period has been all as well simple. Obtain the tick number (an anonymous 64-bit integer) at the first moment, get it at the second, take the initial from the 2nd as well as your answer is already in nanoseconds.
Apple’s only documentation that I can locate is Technical Q&A QA1398, which dates from fifteen years earlier and also has now been archived. Regretfully the CoreServices conversion functions it describes have long since been eliminated from macOS. Possibly with this modification, Apple might like to restore them?
What we need to have been doing was using a conversion aspect to the distinction in clock ticks, to convert from ticks to nanoseconds. Something like:
var info = mach_timebase_info().
mach_timebase_info( & info).
then.
(( secondTicks - firstTicks) * UInt64( info.numer))/ UInt64( info.denom).
returns the moment period in split seconds.
For macOS working on Intel cpus, the numerator and of mach_timebase_info coincide, as well as have typically been omitted. Large Sur operating on Apple Silicon Macs will not be the same, though, the modification may well be large, and also could differ from design to version. If you make use of any type of code which assumes that Mach ticks go to nanosecond intervals, now is the time to integrate this improvement. Some ideas which may work for languages apart from Swift and Objective-C are given in this helpful cross-platform collection.
This additionally influences entries written to the log. Every access in the macOS combined log, consisting of Signposts, features 2 different records of the time. One is in the recognisable layout of a timestamp, such as.
2018-08-19 20:35:41.991370 +0100.
which resolves down to one microsecond (0.000001 of a second). The various other is a straight reading of the Mach absolute time and also called the machTimestamp, which is given in system ticks as a large positive integer like.
1521457734562380.
If you keep or process log documents, the machTimestamp from Apple Silicon Macs will certainly be very various from that of Intel Macs. If you compute time periods from them, you’ll need to fix those utilizing the mach_timebase_info as above.
Unlike cpu directions which are immediately translated from Intel to ARM code by Rosetta 2, if you run an Intel app which utilizes Mach ticks and fails to correct the values (or acquired values, such as time intervals), then all those times will be incorrect on Apple Silicon Macs. I know that this impacts timing values in my very own RouteMap, which computes time intervals in between Signpost entrances in the unified log. I’ll be launching a new version of RouteMap tomorrow to address this.
So don’t be amazed if running older applications on Apple Silicon systems occasionally causes strangeness in time, and also time periods. This is least most likely in apps which were created when PowerPC systems were still about, as well as in those which share code with an iphone version. If you discover an application that is affected by this, there’s absolutely nothing the individual can do other than record it to its developer as a pest.
I sense that a few applications working on Apple Silicon will get this spectacularly incorrect.
https://www.lention.com/
When something does not change for a long period of time we tend to obtain obsequious and reduced corners. For many years, the accuracy Mach appear Macs has ticked away in nanoseconds, and we have actually involved presume that it constantly will. When it’s contacted an entrance in the linked log, because the machTimestamp has actually always remained in split seconds, it’s very easy to presume that it is as well as compute time intervals appropriately.
Apple has actually alerted us that its brand-new Apple Silicon Macs will not be the same, and also continuing to make the presumption that Mach clock ticks occur as soon as every millisecond will show seriously incorrect. If any one of your code uses mach_absolute_time, or anything originated from it, consisting of the machTimestamp field in merged log essences, now is the moment to place your clock right.
As I have clarified formerly, Macs contain a number of different clocks as well as views of the time. Regional referral clocks and timers which currently work in appropriate time systems such as seconds aren’t affected by this change. It’s equipment clock ticks, Mach accuracy time, which alters. On Intel processors, that tick has actually been one split second long, so exercising a time period has been all as well simple. Obtain the tick number (an anonymous 64-bit integer) at the first moment, get it at the second, take the initial from the 2nd as well as your answer is already in nanoseconds.
Apple’s only documentation that I can locate is Technical Q&A QA1398, which dates from fifteen years earlier and also has now been archived. Regretfully the CoreServices conversion functions it describes have long since been eliminated from macOS. Possibly with this modification, Apple might like to restore them?
What we need to have been doing was using a conversion aspect to the distinction in clock ticks, to convert from ticks to nanoseconds. Something like:
var info = mach_timebase_info().
mach_timebase_info( & info).
then.
(( secondTicks - firstTicks) * UInt64( info.numer))/ UInt64( info.denom).
returns the moment period in split seconds.
For macOS working on Intel cpus, the numerator and of mach_timebase_info coincide, as well as have typically been omitted. Large Sur operating on Apple Silicon Macs will not be the same, though, the modification may well be large, and also could differ from design to version. If you make use of any type of code which assumes that Mach ticks go to nanosecond intervals, now is the time to integrate this improvement. Some ideas which may work for languages apart from Swift and Objective-C are given in this helpful cross-platform collection.
This additionally influences entries written to the log. Every access in the macOS combined log, consisting of Signposts, features 2 different records of the time. One is in the recognisable layout of a timestamp, such as.
2018-08-19 20:35:41.991370 +0100.
which resolves down to one microsecond (0.000001 of a second). The various other is a straight reading of the Mach absolute time and also called the machTimestamp, which is given in system ticks as a large positive integer like.
1521457734562380.
If you keep or process log documents, the machTimestamp from Apple Silicon Macs will certainly be very various from that of Intel Macs. If you compute time periods from them, you’ll need to fix those utilizing the mach_timebase_info as above.
Unlike cpu directions which are immediately translated from Intel to ARM code by Rosetta 2, if you run an Intel app which utilizes Mach ticks and fails to correct the values (or acquired values, such as time intervals), then all those times will be incorrect on Apple Silicon Macs. I know that this impacts timing values in my very own RouteMap, which computes time intervals in between Signpost entrances in the unified log. I’ll be launching a new version of RouteMap tomorrow to address this.
So don’t be amazed if running older applications on Apple Silicon systems occasionally causes strangeness in time, and also time periods. This is least most likely in apps which were created when PowerPC systems were still about, as well as in those which share code with an iphone version. If you discover an application that is affected by this, there’s absolutely nothing the individual can do other than record it to its developer as a pest.
I sense that a few applications working on Apple Silicon will get this spectacularly incorrect.
https://www.lention.com/
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