实施繁忙循环的最佳方法? [英] Best way to implement busy loop?

问题描述

实现忙循环的最佳方法是什么?如果我错了纠正我吗?

What is the best way to implement the busy loop ? correct me if i am wrong ?

while (1); // obviously eats CPU. 
while (1) { sleep(100); } // Not sure if it is the correct way ?

推荐答案

要无限等待，对于信号(还有什么)，有一个pause()系统调用.您必须将其放入循环中，因为每次传递信号时它都会返回(总是将-1并且errno设置为EINTR):

To do an infinite wait, for a signal (what else) there is the pause() system call. You'll have to put it in a loop, as it returns (always with -1 and errno set to EINTR) every time a signal is delivered:

while (1)
    pause();

奇怪的是，这是AFAIK唯一记录为总是失败的POSIX函数.

As a curious note, this is, AFAIK the only POSIX function documented to always fail.

更新:感谢dmckee，在下面的注释中，sigsuspend()也总是失败.它的作用与pause()相同，但是对信号更友好.区别在于它具有参数，因此除了EINTR之外，它还会因EFAULT失败.

UPDATE: Thanks to dmckee, in the comments below, sigsuspend() also fails always. It does just the same as pause(), but it is more signal-friendly. The difference is that it has parameters, so it can fail with EFAULT in addition to EINTR.

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