add queue demo

Author: JanHuang

examples/queue.php

@@ -0,0 +1,29 @@
+<?php
+/**
+ * @author    jan huang <bboyjanhuang@gmail.com>
+ * @copyright 2016
+ *
+ * @link      https://www.github.com/janhuang
+ * @link      http://www.fast-d.cn/
+ */
+
+include __DIR__ . '/../vendor/autoload.php';
+
+$queue = new \FastD\Swoole\Queue(function ($worker) {
+    while (true) {
+        $recv = $worker->pop();
+        echo "From Master: $recv\n";
+    }
+});
+
+$queue->start();
+
+while (true) {
+    $queue->push('hello');
+    sleep(1);
+}
+
+
+$queue->wait(function ($ret) {
+    echo 'PID: ' . $ret['pid'];
+});