do {…} while(false)

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小鲜肉
小鲜肉 2020-11-28 03:29

I was looking at some code by an individual and noticed he seems to have a pattern in his functions:

 function()
{
 

        
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  •  孤城傲影
    2020-11-28 03:46

    How old was the author?

    I ask because I once came across some real-time Fortran code that did that, back in the late 80's. It turns out that is a really good way to simulate threads on an OS that doesn't have them. You just put the entire program (your scheduler) in a loop, and call your "thread" routines" one by one. The thread routines themselves are loops that iterate until one of a number of conditions happen (often one being a certain amount of time has passed). It is "cooperative multitasking", in that it is up to the individual threads to give up the CPU every now and then so the others don't get starved. You can nest the looping subprogram calls to simulate thread priority bands.

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