Introduction
Threads Overview
  Demo 1   Demo 2
Stopping Threads
Multi-Processing
Thread Tasks
Animations
  Demo 3   Demo 4  
  Demo 5
Non-interacting
  Demo 6
Task Splitting
  Demo 7
Exclusivity
  Demo 8
Communicating
  Demo 9
Priority/Scheduling
More Thread
Exercises

    Supplements
Java2D Animation
  Demo 1 
Processor View
More Concurrency
Cloning
  Demo 2  Demo 3 

Threads are sub-processes that run in parallel to the main program. On a single processor, of course, the parallelism is only apparent from the high speed switching of programs in and out of the system. Yet, even in that case threading can provide significant benefits.

For example, perhaps one thread takes care of slow I/O tasks such as downloading a file over the internet. Then while that process is waiting for data, other threads can do useful work.

Java makes the creation and running of a thread quite easy. We will concentrate on the basics of threading in this chapter. However, subtleties and complications arise when using multiple threads must interact and access and modify common resources. Avoiding data race and other interference problems among the threads becomes very important.

The sections here cover the following topics:

• Introduction to threads - a brief overview of threads and the two ways to create threads.
  • Demo 1: Thread subclass
  • Demo 2: Implementing Runnable
    
• Stopping Threads - stopping a thread requires killing the thread process entirely by making it return from its run() method.
  
• Multi-Processing - more about topics related using multiple threads.
  
• Thread Tasks - more about where threads are useful.
• Animations - threads are often used to create animated graphics.
  • Demo 3: Text colors
  • Demo 4: Digital Clock
  • Demo 5: Bouncing ball
• We discuss four basic types of multiple thread programs and include a demo for each:
  
  • Non-interacting - threads run with no interaction among each other.
    
  • Task Splitting - several threads attack different parts of the same problem.
    
  • Exclusivity - multiple threads attempt to access the same data. Synchronization techniques must be applied to avoid interference problems such as data race conditions.
    
  • Communicating - multiple threads access each other and also must synchronize to avoid interference problems.
• Priority/Scheduling issues of threads.
• More about threads - brief discussions of some additional thread topics.
• Exercises

Latest update: Nov. 8, 2004

              Tech
Timers
  Demo 1
Hist. Adapt Range
  Demo 2
Sorting in Java
  Demo 3
Histogram Median
  Demo 4
Refactoring
  Demo 5
Error Bars
  Demo 6
Exercises

           Physics
Least Squares Fit
  Demo 1
Fit to Polynomial
  Demo 2
Fit Hist Errors
  Demo 3
Discretization
  Demo 4
Timing
  Demo 5
Exercises