摘要： But we’re still not done. Because generating and reading the select()bit arraystakes time proportional to the largest fd that you provided for select(), the select() call scales terribly when the number of sockets is high.Different operating systems have provided different replacement functions for 阅读全文

摘要： Level Trigger:1) The input signal is sampled when the clock signal is either HIGH or LOW.2) It is sensitive to Glitches.Example: Latch.Edge Trigger:1) The input signal is sampled at the RISING EDGE or FALLING EDGE of the clock signal.2) It is not-sensitive to Glitches.Example: Flipflop.翻译过来一个叫做条件触发（ 阅读全文

摘要： observer pattern是一种事件 订阅/通知 模式，libevent就是使用的这种模式的实现。他允许observer 向 subject订阅某种事件，然后有改动就会通知到observer。a subset of thepublish/subscribe patternThe select() call takes three sets of fds (implemented as bit arrays): one for reading, one for writing, and one for "exceptions". It waits until a soc 阅读全文