PHP7 Builder

Creational/Pool/StringReverseWorker.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace DesignPatterns\Creational\Pool;
+
+class Worker
+{
+    public function __construct()
+    {
+        // let's say that constuctor does really expensive work...
+        // for example creates "thread"
+    }
+
+    public function run($image, array $callback)
+    {
+        // do something with $image...
+        // and when it's done, execute callback
+        call_user_func($callback, $this);
+    }
+}