Ev/watcher-callbacks-Phpdoc专题
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 constructors (the classes derived from EvWatcher - <span class="methodname">EvCheck::__construct , <span class="methodname">EvChild::__construct etc.). A watcher callback should match the following prototype:
void callback
([ object
$watcher = NULL [, <span
class="methodparam"> int $revents <span
class="initializer"> = NULL ]] )
watcher
The watcher instance(of a class extending <span
class="classname">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 <span
class="methodname">EvLoop::child ) sets EV::CHILD , <span
class="classname">EvPrepare (or <span
class="methodname">EvLoop::prepare ) sets Ev::PREPARE ,
EvPeriodic (or <span
class="methodname">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).