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DEBS08(5) - Event-based Constraints
07-07-2008
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EVENT(3) 1 EVENT(3) The Event class INTRODUCTION
Event class represents and event firing on a file descriptor being ready to read from or write to; a file descriptor becoming ready to read from or write to(edge-triggered I/O only); a timeout expiring; a signal occuring; a user-triggered event. Every event is associated with EventBase . However, event will never fire until it is added (via Event::add ). An added event remains in pending state until the registered event occurs, thus turning it to active state. To handle events user may register a callback which is called when event becomes active. If event is configured persistent , it remains pending. If it is not persistent, it stops being pending when it's callback runs. Event::del method deletes event, thus making it non-pending. By means of Event::add method it could be added again. CLASS SYNOPSIS
Event final Event Constants o const integer$Event::ET32 o const integer$Event::PERSIST16 o const integer$Event::READ2 o const integer$Event::WRITE4 o const integer$Event::SIGNAL8 o const integer$Event::TIMEOUT1 Properties o publicreadonly bool$pending Methods o public bool Event::add ([double $timeout]) o public bool Event::addSignal ([double $timeout]) o public bool Event::addTimer ([double $timeout]) o public Event::__construct (EventBase $base, mixed $fd, int $what, callable $cb, [mixed $arg = NULL]) o public bool Event::del (void ) o public bool Event::delSignal (void ) o public bool Event::delTimer (void ) o public void Event::free (void ) o publicstatic array Event::getSupportedMethods (void ) o public bool Event::pending (int $flags) o public bool Event::set (EventBase $base, mixed $fd, [int $what], [callable $cb], [mixed $arg]) o public bool Event::setPriority (int $priority) o public bool Event::setTimer (EventBase $base, callable $cb, [mixed $arg]) o publicstatic Event Event::signal (EventBase $base, int $signum, callable $cb, [mixed $arg]) o publicstatic Event Event::timer (EventBase $base, callable $cb, [mixed $arg]) PROPERTIES
o $pending - Whether event is pending. See About event persistence . PREDEFINED CONSTANTS
o Event::ET - Indicates that the event should be edge-triggered, if the underlying event base backend supports edge-triggered events. This affects the semantics of Event::READ and Event::WRITE . o Event::PERSIST - Indicates that the event is persistent. See About event persistence . o Event::READ - This flag indicates an event that becomes active when the provided file descriptor(usually a stream resource, or socket) is ready for reading. o Event::WRITE - This flag indicates an event that becomes active when the provided file descriptor(usually a stream resource, or socket) is ready for reading. o Event::SIGNAL - Used to implement signal detection. See "Constructing signal events" below. o Event::TIMEOUT - This flag indicates an event that becomes active after a timeout elapses. The Event::TIMEOUT flag is ignored when constructing an event: one can either set a timeout when event is added , or not. It is set in the $what argument to the callback function when a timeout has occurred. PHP Documentation Group EVENT(3)