Chapter 1. Introduction to Threads
This is a book about using threads in the Java programming language
and the Java virtual machine. The topic of threads is very important
in Java梥o important that many features of the threading system
are built into the Java language itself while other features of the
threading system are required by the Java virtual machine. Threading
is an integral part of using Java.
The concept of threads is not a new one: for some time, many
operating systems have had libraries that provide the C programmer a
mechanism to create threads. Other languages, such as Ada, have
support for threads embedded into the language, much as support for
threads is built into the Java language. Nonetheless, until Java came
along, the topic of threads was usually considered a peripheral
programming topic, one that was only needed in special programming
cases.
With Java, things are different: it is impossible to write any but
the simplest Java program without introducing the topic of threads.
And the popularity of Java ensures that many developers, who might
never have considered learning about threading possibilities in a
language such as C or C++, need to become fluent in threaded
programming.
Futhermore, the Java platform has matured throughout the years. In
Java 2 Standard Edition Version 5.0 (J2SE 5.0), the classes available
for thread-related programming rival many professional threading
packages, mitigating the need to use any commercial library (as was
somewhat common in previous releases of Java). So Java developers not
only need to become knowledgeable in threaded programming to write
basic applications but will want to learn the complete, rich set of
classes available for writing complex, commercial-grade applications.
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