调试函数耗时的利器CFAbsoluteTimeGetCurrent

转载自:   http://blog.youkuaiyun.com/gghu1986/article/details/8662293

1. CFAbsoluteTime start = CFAbsoluteTimeGetCurrent();  
2. // do something  
3.  CFAbsoluteTime end = CFAbsoluteTimeGetCurrent();  
4.  NSLog(@"time cost: %0.3f", end - start);