php中的并行性

Question

I want to optimize part of my code to improve performance.Since my application make use of commandline tool , i think it would certainly improve performance to execute lines of code in parallel rather than executing code sequentially

<?php
$value = exec("command goes here"); //this takes time
/* Some instructions here that don't depend on $value */
/* Some instructions here that don't depend on $value */

$result = $value*2 ; //this is just a dumb example

?>  

I want to execute the codes that don't depend on value at the same time as $value so that the whole script execute faster rather that waiting for exec() to complete

Answer 1

Unfortunately PHP always despond you in parallelism, concurrent programming, .... And I never know that why PHP doesn't support these important things and WHEN PHP WANT TO SUPPORT THESE.

But maybe you want to use Fork in php (if you know the problems AND Troubles in Fork )

http://php.net/manual/en/function.pcntl-fork.php

https://codereview.stackexchange.com/questions/22919/how-to-fork-with-php-4-different-approaches