V. Java Language Threading Features

A. Threads and Runnables

• Two related ways to create threads in Java. 
  • Extend the class java.lang.Thread. 
  • Implement interface java.lang.Runnable, give an instance to a Thread.
• Either way, a run() method executes once the Thread’s start() method is called.
• Keyword synchronized insures block of code, or method, is executed by one thread at a time.
• Method join() is another important synchronization device.

B. Threads – The Conceptual and Semantic Challenge

• A Java Thread object is similar to any instance – 
  • instantiated and managed by the ClassLoader like any other object.
• An OS Thread is an operating system construct 
  • manages the execution of the code in a Java Thread’s run() method.
• After OS Thread termination, Java Thread object remains. 
  • Its accessors can be invoked to retrieve member data.

C. Example:  

Run “multithreading”