iOS精准计算代码运行耗时

2018-01-03 1,093 阅读1分钟

如果要准确地计算代码运行的时间，用NSDate总感觉不靠谱。下面这个方法，我试过很好用。首先引用mach_time头 #import <mach/mach_time.h> 然后把下面的代码嵌入你要计算运行耗时的代码中

uint64_t start = mach_absolute_time();
/*需要计算运行耗时的代码*/
uint64_t end = mach_absolute_time();
uint64_t elapsed = end - start;mach_timebase_info_data_t info;
if (mach_timebase_info (&info) != KERN_SUCCESS) 
{    
	printf ("mach_timebase_info failed\n");
}
uint64_t nanosecs = elapsed * info.numer / info.denom;
uint64_t millisecs = nanosecs / 1000000;
NSLog(@">>>>>>>>>>cost time = %lld ms", millisecs);

本文转自：http://blog.csdn.net/yexiaozi_007/article/details/7966934