一直有一个疑问,就是如果在关闭中断期间有新的中断到达,新中断是会被丢弃还是会在当前中断结束后立即响应?

  答案是后者。

  下面摘自http://linux.linti.unlp.edu.ar/images/0/0c/ULK3-CAPITULO4-UNNOBA.pdf (需要翻墙)

  The PIC can be told to stop issuing interrupts that refer to a given IRQ line, or to 
resume issuing them. 
  Disabled interrupts are not lost; the PIC sends them to the CPU as soon as they are 
enabled again. 

  This feature is used by most interrupt handlers, because it allows them to process 
IRQs of the same type serially.


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