(PECL ev >= 0.2.0)
EvLoop::nowUpdate — Establishes the current time by querying the kernel, updating the time returned by EvLoop::now in the progress
Establishes the current time by querying the kernel, updating the time returned by EvLoop::now() in the progress. This is a costly operation and is usually done automatically within EvLoop::run() .
此函数没有参数。
没有返回值。