改变程序的执行时间

Question

I have a program that takes a text file, read each line and then insert each line to a list. I used stopwatch to calculate time of execution. But there is some droll result! I'll give various elapsed time when I run the program each time (difference is about 1 or 2 seconds).

The text file involves 3 million URLs.

Any idea??!

Answer 1

The processing time for a set of commands depends on (but is not limited to):

• the CPU speed
• the efficency of your code
• asyn vs sync methods
• network speed
• the networked computer
• hard drive speed
• ram
• my mood
• ...

I could go on for days here. The point is (as TheifMaster said), there are so many variables at stake here that it would be a miracle if your code had the same time for any 2 runs! It's the "every snowflake is different" methodology. With so many environment variables, no 2 runs will be the same.

Don't fret on time differences, just focus on getting the average time as low as you need to.

Answer 2

某些波动是完全正常的，尤其是当代码涉及IO（例如读取文件）时。