Question

Even if use

spl_register_autoload( function( $class )
{
    $file = '/path/to/lib/' . $class;
    require_once( $file );
    return class_exists( $class, false );
} );

xdebug shows that total self cost for this closure (19%) is a little less than its inclusive cost (25%). And it’s 10 times higher then PDO’s execute() (2%).

Why does it takes so much time?

Answer 1

Seems xdebug takes included file’s code as closure’s code. That’s why are such results.
I’ve found it out when modified included files.
As I ‘m using APC, execution time has been increased. It has affected closure’s self cost.