我一直注意到我在Logic Pro X中的音乐有各种奇怪的时机，而且我看到系统时钟的纳秒时间有很大的波动。我决定创建一个for循环并比较差异，我注意到一些非常奇怪的东西，我原本认为是一个软件问题？ 重现步骤：
>>> from Foundation import *
>>> for i in range(1,32):
... now = NSProcessInfo.processInfo().systemUptime()
... delta = now - prev
... prev = now
... print str(now) + ", delta=" + str(delta)
... time.sleep(1)
...
13021.1874697, delta=13021.1874697
13022.1882823, delta=1.00081255
13023.1883955, delta=1.000113186
13024.1894656, delta=1.001070095
13025.1896117, delta=1.000146088
13026.1906813, delta=1.001069595
13027.1917512, delta=1.001069892
13028.1929504, delta=1.001199214
13029.1941442, delta=1.001193793
13030.1953468, delta=1.001202675
13031.196421, delta=1.001074142
13032.1975382, delta=1.00111725
13033.1982311, delta=1.000692907
13034.1984295, delta=1.000198325
13035.1986785, delta=1.000248999
13036.1990507, delta=1.000372273
13037.1993152, delta=1.000264465
13038.1996434, delta=1.000328253
13039.2000955, delta=1.000452101
13040.2011615, delta=1.001065969
13041.2021225, delta=1.000960959
13042.2031759, delta=1.001053454
13043.2037789, delta=1.000602964
13044.2044619, delta=1.000683005
13045.2048414, delta=1.00037947
13046.206041, delta=1.00119968
13047.2065136, delta=1.000472508
13048.2066852, delta=1.000171626
13049.2077582, delta=1.001073025
13050.2087482, delta=1.000990021
13051.2090188, delta=1.000270521
>>>