PHP Manual
Ev
Watcher callbacks

Watcher callbacks

All watchers can be active(waiting for events) or inactive(paused). Only active watchers will have their callbacks invoked. All callbacks will be called with at least two arguments: watcher - the watcher, and revents a bitmask of received events.

Watcher callbacks are passed to the watcher contructors(the classes derived from EvWatcher - EvCheck::__construct() , EvChild::__construct() etc.). A watcher callback should match the following prototype:

callback ([ object $watcher = NULL [, int $revents = NULL ]] ) : void

watcher: The watcher instance(of a class extending EvWatcher ).
revents: Watcher received events .

Each watcher type has its associated bit in revents , so one can use the same callback for multiple watchers. The event mask is named after the type, i.e. EvChild (or EvLoop::child() ) sets EV::CHILD , EvPrepare (or EvLoop::prepare() ) sets Ev::PREPARE , EvPeriodic (or EvLoop::periodic() ) sets Ev::PERIODIC and so on, with the exception of I/O events (which can set both Ev::READ and Ev::WRITE bits).

php ev returns the set of backends that are embeddable in other event loops php ev 范例 php ev feed a signal event info ev php ev feed signal event into the default loop php ev periodic watcher operation modes php ev begin checking for events and calling callbacks for the default loop php ev block the process for the given number of seconds php ev stops the default event loop php ev returns the set of backends supported by current libev configuration php ev suspend the default event loop php ev watcher callbacks php evfork constructs the evfork watcher object php evloop creates evfork watcher object associated with the current event loop instance php evloop creates evidle watcher object associated with the current event loop instance php evperiodic simply stops and restarts the periodic watcher again php evperiodic returns the absolute time that this watcher is supposed to trigger next php evtimer restarts the timer watcher php evtimer constructs an evtimer watcher object php libevent 函数 set or reset callbacks for a buffered event php zookeeper 函数 calls callbacks for pending operations