Code and execution state Strong mobility - Migration mechanisms management Reactive Remote cloning— Proactive Reactive Weak mobility Code shipping Stand-alone Synchronous Asynchronous-Immediate Deferred Code Synchronous Code fetchin Stand-alone code Synchronous synchronous-TImmedlate ragment Synchronous Asynchronous Immediate ata spa ding removal management Network reference By copy By move 2021/24 Institute of Computer Software, Nanjing University 152021/2/4 Institute of Computer Software, Nanjing University 15