Chapter 8. Threads and Collection Classes
In this chapter, we'll look at how threads interact
with the collection classes provided by Java. We'll
examine some synchronization issues and how they affect our choice
and usage of collection classes.
The collection classes comprise many of the classes in the
java.util package (and, in J2SE 5.0, some of the
classes in the java.util.concurrent package).
Collection classes are used to store objects in some data structure:
a hashtable, an array, a queue, and so on. Collection classes
interact with Java threads in a few areas:
Collection classes may or may not be threadsafe, so threads that use
those classes must understand their synchronization requirements. Not all collections have the same performance with regard to thread
synchronization, so threads that use them must understand the
conditions in which they can be used optimally. Newer collection classes automatically provide some threading
semantics (such as using thread notification when their data
changes). Threads commonly use collection classes to share data.
We begin this chapter with an overview of the collection classes; the
overview addresses the thread-safety of the various classes. Next, we
show how some of the newer collection classes interact with threads.
And finally, we show a common design pattern in which multiple
threads use the collections: the
producer-consumer model.
|
