Introduces the Java Thread API, outlines issues involved in multithreading, and offers solutions to common problems. By Alex Roetter.

Many authors advocate the double-checked locking idiom to access a Singleton object in an intuitively thread-safe way. Unfortunately, for counterintuitive reasons, double-checked locking doesn't work in Java.

Takes a look at the semantics and the performance penalty of Java's synchronized keyword. By Brian Goetz.

Explains why contended synchronization is a problem and then explores several techniques for reducing contention, and hence improving scalability.

Examines ThreadLocal and offers tips for exploiting its power. By Brian Goetz.

Introduces basic concurrency problems and shows how to solve them by using builtin Java synchronization primitives. (Only sources free accessed without registration)

Producer Consumer, Dining Philosophers, Reader Writer problems. Applet demonstration, design diagram. Source code accessible by e-mail request.

Explores the motivations for thread pools, some basic implementation and tuning techniques, and some common hazards to avoid.

Details on the reasons - some very subtle - why double-checked locking cannot be relied upon to be safe. Signed by a number of experts, including Sun engineers.

Presents two approaches to creating thread-safe singletons.