Join validations for Mac OS

Worker.php

@@ -2148,13 +2148,13 @@ class Worker
         $backtrace                = \debug_backtrace();
         $this->_autoloadRootPath = \dirname($backtrace[0]['file']);
 
-        if (static::$_OS === OS_TYPE_LINUX && version_compare(PHP_VERSION,'7.0.0', 'ge')) {
-            $php_uname = strtolower(php_uname('s'));
         // If not Mac OS then turn reusePort on.
-            if ($php_uname !== 'darwin') {
+        if (static::$_OS === OS_TYPE_LINUX 
+                            && version_compare(PHP_VERSION,'7.0.0', 'ge')
+                            && strtolower(php_uname('s')) !== 'darwin') {
+
             $this->reusePort = true;
         }
-        }
 
         // Context for socket.
         if ($socket_name) {