Skip to Main Content
Java Threads, 3rd Edition
book

Java Threads, 3rd Edition

by Scott Oaks, Henry Wong
September 2004
Intermediate to advanced content levelIntermediate to advanced
362 pages
11h 24m
English
O'Reilly Media, Inc.
Content preview from Java Threads, 3rd Edition

Chapter 12. Threads and I/O

If you’re not interested in parallel processing, the area where you’re most likely to encounter threads in Java is in dealing with I/O—and particularly in dealing with network I/O. That’s the topic we explore in this chapter.

In early versions of Java, all I/O was blocking. If your program attempted to read data from a socket and no data was present, the read() method would block until at least some data was available. That situation is also true of reading a file. For the most part, delays in reading files aren’t noticeable; you may have to wait a few cycles for the disk to rotate to the correct location and the operating system to transfer data from the disk. In most programs, blocking for that amount of time makes little difference, but in those programs where it does make a difference, the concepts that apply to network I/O are just as relevant to file I/O.

For network I/O, the delay can be quite significant. Networks are subject to delays at various points (particularly if the network involves long distances or slow links). Even if there’s no physical delay on the network lines, network I/O is done in the context of a conversation between two peers, and a peer may not be ready to furnish its output when its partner wants it. A database server reads commands from a user, but the user may take a few minutes to type in the SQL to be executed. Once the SQL has been sent to the database, the user is ready to read back the response, but it may take the database ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Java Performance: The Definitive Guide

Java Performance: The Definitive Guide

Scott Oaks
Java Concurrency, 2/e

Java Concurrency, 2/e

Douglas Schmidt
Java Swing, 2nd Edition

Java Swing, 2nd Edition

Dave Wood, Robert Eckstein, Marc Loy, James Elliott, Brian Cole

Publisher Resources

ISBN: 0596007825Supplemental ContentErrata Page