About buffer event callbacks
EventConfig::avoidMethod
Event
PHP Manual

# The EventConfig class

(PECL event >= 1.2.6-beta)

## Introduction

Represents configuration structure which could be used in construction of the EventBase .

## Class synopsis

final EventConfig {
/* Constants */
const integer FEATURE_ET = 1 ;
const integer FEATURE_O1 = 2 ;
const integer FEATURE_FDS = 4 ;
/* Methods */
public bool avoidMethod ( int `$method` )
public __construct ( void )
public bool requireFeatures ( int `$feature` )
public void setMaxDispatchInterval ( int `$max_interval` , int `$max_callbacks` , int `$min_priority` )
}

## Predefined Constants

`EventConfig::FEATURE_ET`

  Requires a backend method that supports edge-triggered I/O.

`EventConfig::FEATURE_O1`

  Requires a backend method where adding or deleting a single event, or having a single event become active, is an O(1) operation.

`EventConfig::FEATURE_FDS`

  Requires a backend method that can support arbitrary file descriptor types, and not just sockets.

## Table of Contents

- EventConfig::avoidMethod — Tells libevent to avoid specific event method
- EventConfig::__construct — Constructs EventConfig object
- EventConfig::requireFeatures — Enters a required event method feature that the application demands
- EventConfig::setMaxDispatchInterval — Prevents priority inversion

About buffer event callbacks
EventConfig::avoidMethod
Event
PHP Manual