简介

This extension provides asyncronous POSIX I/O by means of » libeio C library written by Marc Lehmann.

Note: 此扩展在 Windows 平台上不可用。

Warning

It is important to aware that each request is executed in a thread, and the order of execution of continuously queued requests basically is unpredictable. For instance, the following piece of code is incorrect.

Example #1 Incorrect requests

  <?php
 // Request to create symlink of $filename to $link
 eio_symlink ( $filename ,  $link );

 // Request to move $filename to $new_filename
 eio_rename ( $filename ,  $new_filename );

 // Process requests
 eio_event_loop ();
 ?>

In the example above eio_rename() request may finish before eio_symlink() . To fix it you might call eio_rename() in the callback of eio_symlink() :

Example #2 Calling request from a request callback

  <?php
 function  my_symlink_done ( $filename ,  $result ) {
  // Request to move $filename to $new_filename
  eio_rename ( $filename ,  "/path/to/new-name" );

  // Process requests
  eio_event_loop ();
}

 // Request to create symlink of $filename to $link
 eio_symlink ( $filename ,  $link ,  EIO_PRI_DEFAULT ,  "my_symlink_done" ,  $filename );

 // Process requests
 eio_event_loop ();
 ?>

Alternatively, you might want to create a request group:

Example #3 Calling request from a request callback

  <?php
 
 function  my_grp_done ( $data ,  $result ) {
  // ...
 }

function  my_symlink_done ( $filename ,  $result ) {
  // Create eio_rename request and add it to the group
  $req  =  eio_rename ( $filename ,  "/path/to/new-name" );
  eio_grp_add ( $grp ,  $req );
  // You might want to add more requests...
 }

 // Create a request group
 $grp  =  eio_grp ( "my_grp_done" ,  "my_grp_data" );

 // Create eio_symlink request and add it to the group
// Pass $filename to the callback
 $req  =  eio_symlink ( $filename ,  $link ,
   EIO_PRI_DEFAULT ,  "my_symlink_done" ,  $filename );
 eio_grp_add ( $grp ,  $req );

 // Process requests
 eio_event_loop ();
 ?>

Group is a special kind of request that could accumulate a set of regular eio requests. This could be used to create a complex request that opens, reads and closes a file.

Since version 0.3.0 alpha, a variable used in communications with libeio internally, could be retrieved with eio_get_event_stream() . The variable could be used to bind to an event loop supported by some other extension. You might organize a simple event loop where eio and libevent work together:

Example #4 Using eio with libevent

  <?php
 function  my_eio_poll ( $fd ,  $events ,  $arg ) {
     
     if ( eio_nreqs ()) {
         eio_poll ();
    }
     
 }

function  my_res_cb ( $d ,  $r ) {
     var_dump ( $r );  var_dump ( $d );
}

 $base  =  event_base_new ();
 $event  =  event_new ();

 // This stream is used to bind with libevent
 $fd  =  eio_get_event_stream ();

 eio_nop ( EIO_PRI_DEFAULT ,  "my_res_cb" ,  "nop data" );
 eio_mkdir ( "/tmp/abc-eio-temp" ,  0750 ,  EIO_PRI_DEFAULT ,  "my_res_cb" ,  "mkdir data" );
 


// set event flags
 event_set ( $event ,  $fd ,  EV_READ   ,  "my_eio_poll" , array( $event ,  $base ));

 // set event base 
 event_base_set ( $event ,  $base );

 // enable event
 event_add ( $event );

 // start event loop
 event_base_loop ( $base );

 
 ?>