硬实时，软实时和实时的差异？(Differences between hard real-time, soft real-time, and firm real-time?)

 我已经阅读了实时的不同概念的定义，为硬和软的实时系统提供的例子对我来说是有意义的。 但是，实体系统并没有真正的解释或例子。 根据以上链接： 
 
 
 
 公司：偶然的期限错误是可以忍受的，但可能会降低系统的服务质量。 结果的有用性在其截止日期之后为零。 
 
 
 公司实时与硬实时或软实时之间有明确的区别，有没有一个很好的例子说明这个区别？ 
 
 在评论中，Charles要求我为新标签提交标签维基。 我为企业实时标签提供的“公司实时系统”的例子是一个牛奶服务系统。 如果系统在其过期后提供牛奶，那么牛奶被认为是“无用的”。 人们可以忍受吃没有牛奶的谷物，但经验的质量会降低。 
 
 这只是我最初读取定义时我头脑中形成的想法。 我正在寻找一个更好的例子，也许是一个更好的企业实时定义，将改善我的观念。 

I have read the definitions for the different notions of real-time, and the examples provided for hard and soft real-time systems make sense to me. But, there is no real explanation or example of a firm real-time system. According to the link above:
 
 
 
Firm: Infrequent deadline misses are tolerable, but may degrade the system's quality of service. The usefulness of a result is zero after its deadline.
 
 
Is there a clear distinction between firm real-time vs. hard or soft real-time, and is there a good example that illustrates that distinction?
 
In comments, Charles asked that I submit tag wikis for the new tags. The example of a "firm real-time system" I provided for the firm-real-time tag was a milk serving system. If the system delivers milk after its expiration time, then the milk is considered "not useful". One can tolerate eating cereal without milk, but the quality of the experience is degraded.
 
This is just the idea I formed in my head when I initially read the definition. I am looking for a much better example, and perhaps a better definition of firm real-time that will improve my notion of it.

原文：https://stackoverflow.com/questions/17308956