evprepare(3) [php man page]

EVPREPARE(3)								 1							      EVPREPARE(3)

The EvPrepare class

INTRODUCTION

       EvPrepare and EvCheck watchers are usually used in pairs. EvPrepare watchers get invoked before the process blocks, EvCheck afterwards.

	It  is	not allowed to call EvLoop::run or similar methods or functions that enter the current event loop from either EvPrepare or EvCheck
       watchers. Other loops than the current one are fine, however. The rationale behind this is that one don't need to check	for  recursion	in
       those  watchers,  i.e. the sequence will always be: EvPrepare -> blocking -> EvCheck , so having a watcher of each kind they will always be
       called in pairs bracketing the blocking call.

	The main purpose is to integrate other event mechanisms into libev and their use is somewhat advanced. They could be used, for example, to
       track variable changes, implement custom watchers, integrate net-snmp or a coroutine library and lots more. They are also occasionally use-
       ful to cache some data and want to flush it before blocking.

	It is recommended to give EvCheck watchers highest( Ev::MAXPRI ) priority, to ensure that they are being run  before  any  other  watchers
       after the poll (this doesn't matter for EvPrepare watchers).

	Also,  EvCheck	watchers  should  not  activate/feed events. While libev fully supports this, they might get executed before other EvCheck
       watchers did their job.

CLASS SYNOPSIS

       EvPrepare

       EvPrepareextends
       EvWatcher

       Inherited properties

       o public$is_active

       o public$data

       o public$is_pending

       o public$priority

       Methods

       o public EvPrepare::__construct (string	$callback, [string  $data], [string  $priority])

       o finalpublicstatic EvPrepare EvPrepare::createStopped NULL (callable  $callback, [mixed  $data], [int  $priority])

       Inherited methods

       o public int EvWatcher::clear (void  )

       o abstractpublic EvWatcher::__construct (void  )

       o public void EvWatcher::feed (int  $revents)

       o public EvLoop EvWatcher::getLoop (void  )

       o public void EvWatcher::invoke (int  $revents)

       o public bool EvWatcher::keepalive ([bool  $value])

       o public void EvWatcher::setCallback (callable  $callback)

       o public void EvWatcher::start (void  )

       o public void EvWatcher::stop (void  )

PHP Documentation Group 													      EVPREPARE(3)

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EVCHILD(3)								 1								EVCHILD(3)

The EvChild class

INTRODUCTION

       EvChild	watchers trigger when the process receives a SIGCHLD in response to some child status changes (most typically when a child dies or
       exits). It is permissible to install an EvChild watcher after the child has been forked(which implies it might  have  already  exited),	as
       long as the event loop isn't entered(or is continued from a watcher), i.e. forking and then immediately registering a watcher for the child
       is fine, but forking and registering a watcher a few event loop iterations later or in the next callback invocation is not.

	It is allowed to register EvChild watchers in the default loop only.

CLASS SYNOPSIS

       EvChild

       EvChildextends
       EvWatcher

       Properties

       o public$pid

       o public$rpid

       o public$rstatus

       Inherited properties

       o public$is_active

       o public$data

       o public$is_pending

       o public$priority

       Methods

       o public EvChild::__construct NULL (int	$pid, bool  $trace, callable  $callback, [mixed  $data], [int  $priority])

       o finalpublicstatic object EvChild::createStopped (int  $pid, bool  $trace, callable  $callback, [mixed	$data], [int  $priority])

       o public void EvChild::set (int	$pid, bool  $trace)

       Inherited methods

       o public int EvWatcher::clear (void  )

       o abstractpublic EvWatcher::__construct (void  )

       o public void EvWatcher::feed (int  $revents)

       o public EvLoop EvWatcher::getLoop (void  )

       o public void EvWatcher::invoke (int  $revents)

       o public bool EvWatcher::keepalive ([bool  $value])

       o public void EvWatcher::setCallback (callable  $callback)

       o public void EvWatcher::start (void  )

       o public void EvWatcher::stop (void  )

PROPERTIES

	      o $pid
		- Readonly . The process ID this watcher watches out for, or 0 , meaning any process ID.

	      o $rpid
		- Readonly .The process ID that detected a status change.

	      o $rstatus
		- Readonly . The process exit status caused by $rpid .

PHP Documentation Group 														EVCHILD(3)

Linux and UNIX Man Pages

evprepare(3) [php man page]

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