(PECL eio >= 0.0.1dev)
eio_custom — Execute custom request like any other eio_* call.
   eio_custom() executes custom function specified by
   execute processing it just like any other eio_* call.
  
executeSpecifies the request function that should match the following prototype:
      mixed execute(mixed data);
      callback is event completion callback that should match the following
      prototype:
      
      void callback(mixed data, mixed result);
      data is the data passed to
     execute via data argument
      without modifications
      result value returned by execute
     
    priThe request priority: EIO_PRI_DEFAULT, EIO_PRI_MIN, EIO_PRI_MAX, or NULL.
If NULL passed, pri internally is set to
EIO_PRI_DEFAULT.
callback
callback function is called when the request is done.
It should match the following prototype: 
void callback(mixed $data, int $result[, resource $req]);
datais custom data passed to the request.
resultrequest-specific result value; basically, the value returned by corresponding system call.
reqis optional request resource which can be used with functions like eio_get_last_error()
data
     Arbitrary variable passed to callback.
     
   eio_custom() returns request resource on success or FALSE on error.
  
Example #1 eio_custom() example
<?php
/* Callback for the custom callback */
function my_custom_callback($data, $result) {
    var_dump($data);
    var_dump(count($result));
    var_dump($result['data_modified']);
    var_dump($result['result']);
}
/* The custom request */
function my_custom($data) {
    var_dump($data);
    $result  = array(
        'result'        => 1001,
        'data_modified' => "my custom data",
    );
    return $result;
}
$data = "my_custom_data";
$req = eio_custom("my_custom", EIO_PRI_DEFAULT, "my_custom_callback", $data);
var_dump($req);
eio_event_loop();
?>
The above example will output something similar to:
resource(4) of type (EIO Request Descriptor) string(14) "my_custom_data" string(14) "my_custom_data" int(2) string(14) "my custom data" int(1001)