This section describes processes of multi-tasking operating systems and threads of multi-threading applications. Java is a programming language that allows you write multi-threading applications.
What is a thread? What is a process? Answers are in the following explanations:
There are 3 levels of executions of computer instructions on a computer system:
CPU Level: There is only one flow of execution on the
central processing unit (CPU), that is the operating system (OS).
OS Level: For a multi-tasking OS, multiple application programs
can be managed to be executed simultaneously. Here, a flow of execution is called
a process.
Application Level: For a well written application program, multiple
sections of codes can be managed to be executed simultaneously. Here, a flow of
execution is called a thread. A program that can manage multiple threads
is called a multi-threading program.
A good example of multi-threading programs are computer games that simulate
real time activities of multiple human characters and/or moving objects.
Under the Java architecture, the Java virtual machine (JVM) will provide
all the help you need to create and manage multiple threads in your Java applications.
Read subsequent sections for tutorial examples.
