The Java Tutorial Fourth Edition: A Short Course on the Basics

Chapter 12. Concurrency COMPUTER users take it for granted that their systems can do more than one thing at a time. They assume that they can continue to work in a word processor, while other applications download files, manage the print q...

Processes and Threads In concurrent programming, there are two basic units of execution: processes and threads. In the Java programming language, concurrent programming is mostly concerned with threads. However, processes are also important. A co...

Thread Objects Each thread is associated with an instance of the class THRead.[2] There are two basic strategies for using Thread objects to create a concurrent application:[2] docs/api/java/lang/Thread.html To directly control thread creation ...

Synchronization Threads communicate primarily by sharing access to fields and the objects reference fields refer to. This form of communication is extremely efficient, but makes two kinds of errors possible: thread interference and memory consiste...

Liveness A concurrent application's ability to execute in a timely manner is known as its liveness. This section describes the most common kind of liveness problem, deadlock, and goes on to briefly describe two other liveness problems, starvation ...

Guarded Blocks Threads often have to coordinate their actions. The most common coordination idiom is the guarded block. Such a block begins by polling a condition that must be true before the block can proceed. There are a number of steps to follo...

Immutable Objects An object is considered immutable if its state cannot change after it is constructed. Maximum reliance on immutable objects is widely accepted as a sound strategy for creating simple, reliable code. Immutable objects are parti...

High-Level Concurrency Objects So far, this chapter has focused on the low-level APIs that have been part of the Java platform from the very beginning. These APIs are adequate for very basic tasks, but higher-level building blocks are needed for...

For Further Reading Concurrent Programming in Java: Design Principles and Pattern (2nd Edition) by Doug Lea. A comprehensive work by a leading expert, who's also the architect of the Java platform's concurrency framework.Java Concurrency in Practi...

Questions and Exercises: Concurrency Questions Can you pass a Thread object to Executor.execute? Would such an invocation make sense? Exercises 1.Compile and run BadThreads.java:[41][41] tutorial/essential/concurrency/QandE/BadThreads.j...