In the case of epoll(), using the edge-triggered interface it will only report an event when the status of the monitored file descriptor changes (eg from "not r

In the case of epoll(), using the edge-triggered interface it will only report an event when the status of the monitored file descriptor changes (eg from "not readable" to "readable"), whereas when using the level-triggered interface it will continue to report the event as long as the monitored file descriptor remains in the relevant state. For example, if a socket is reported as readable but you only read some of the available data before calling epoll() again, with the edge-triggered interface it won't be reported as readable the next time you check, but with the level-triggered interface it will be.