Multi-Threading by Implementing Runnable Interface

     I have shared enough theory on Multi-Threading in my previous post. Now, it is time to share code for Multi-Threaded programs by implementing runnable interface.

Multithreading by Extending Thread Class

Multi-threading is a topic, that I found most difficult to understand. First thing that needs to be understood is the distinction between a Thread and a Program. Thread is the smallest unit of execution. A program may contain more than one thread that executes concurrently. Let me tell you that saying concurrent execution is not correct, a computer processor can execute only one process at a time (single core processors), and if a process involves more than one Thread, only one Thread, would execute at a time, when a Thread gets paused, then and then only, any other Thread can start executing. If you ask what exactly is the advantage of multi-threading, then the advantage of multi-threading is that you can assign different tasks to Threads, for example, As in Android, Image Retrieval from database is time consuming and processor intensive task, so it is preferred to implement image retrieval mechanism on a separate thread.