Java

Media publications

• A Proposal for Fixing the Java Programming Language's Threading Problems - Java's threading model is entirely inadequate for programs of realistic complexity and isn't in the least bit object oriented. (Published 2000.10.10)
• Achieve Strong Performance With Threads, Part 1 - Gives an introduction to threads and explores the Thread class and runnables. (Published 2002.05.00)
• Achieve Strong Performance With Threads, Part 2 - Explains synchronization, Java's synchronization mechanism, and two problems that arise when developers fail to use that mechanism correctly. (Published 2002.06.00)
• Achieve Strong Performance With Threads, Part 3 - Explains how priority relates to thread scheduling and how to use the wait/notify mechanism to coordinate the activities of multiple threads. (Published 2002.07.00)
• Achieve Strong Performance With Threads, Part 4 - Focuses on thread groups, volatility, thread-local variables, timers, and the ThreadDeath class. Also describes how various thread concepts combine to finalize objects. (Published 2002.08.00)
• Avoid Synchronization Deadlocks - Explains how to apply consistent rules for acquiring multiple locks simultaneously, to reduce the likelihood of synchronization deadlocks. (Published 2001.10.00)
• Can Double-Checked Locking be Fixed? - In this article, Brian Goetz looks at some of the commonly proposed fixes and shows how each of them fails to render the DCL idiom thread-safe under the Java Memory Model. (Published 2001.05.00)
• Can ThreadLocal Solve the Double-checked Locking Problem? - Explains how to fix the double-checked locking idiom by using thread-local variables and takes a look at its performance. (Published 2001.11.00)
• Double-checked Locking and the Singleton Pattern - Examines the roots of the double-checked locking idiom, why it was developed, and why it doesn't work. (Published 2002.05.00)
• Double-Checked Locking: Clever, but Broken - Though many Java books and articles recommend double-checked locking, unfortunately, it is not guaranteed to work in Java. (Published 2001.02.00)
• Ease Your Multithreaded Application Programming - Takes a look at one of the most-used constructs in multithreaded programming: the producer-consumer scenario. Also shows a Consumer class which facilitates code reuse and simplifies debugging and maintenance in some multithreaded applications. (Published 2002.02.00)
• Going Atomic - Explains how the new atomic variable classes in JDK 5.0 enable the development of highly scalable nonblocking algorithms in the Java language. (Published 2004.11.23)
• Hey, where'd my thread go? - If you're not careful, threads can disappear from server applications without a (stack) trace. In this article, threading expert Brian Goetz offers some techniques for both prevention and detection of threads going AWOL. (Published 2002.09.00)
• Multithreading in Java - The article discusses how to pull off multithreading in Java. It is excerpted from chapter 10 of the book Java Demystified, written by Jim Keogh. (Published 2005.08.04)
• Programming Java Threads in the Real World, Part 1 - Discusses the things you need to know to program threads in the real world. This article assumes you understand the language-level support for threads and focuses on the legion of problems that arise when you try to use these language features. (Published 1998.09.00)
• Programming Java Threads in the Real World, Part 2 - Discusses the perils that can arise when you approach multithreading in a naive way. (Published 1998.10.00)
• Programming Java Threads in the Real World, Part 3 - Looks at how and why you might want to roll your own exclusion semaphores, and presents a lock manager that will help you safely acquire multiple semaphores. (Published 1998.11.00)
• Programming Java Threads in the Real world, Part 4 - A condition variable adds to wait the ability to not wait when the condition you're waiting for has already taken place; and a counting semaphore lets you control a pool of resources without sucking up machine cycles in polling loops. (Published 1998.12.00)
• Programming Java Threads in the Real World, Part 5 - Timers let you perform fixed-interval operations, such as animation refreshes. (Published 1999.02.00)
• Programming Java Threads in the Real World, Part 6 - How to implement the Observer pattern (used by AWT/Swing for its event model) in a multithreaded environment. (Published 1999.03.00)
• Programming Java Threads in the Real World, Part 7 - Reader/writer locks let multiple threads safely access a shared resource in an efficient way. (Published 1999.04.00)
• Programming Java Threads in the Real World, Part 8 - Discusses architectural solutions to threading problems. Takes a look at threads from the perspective of an object-oriented designer, and at how to implement threads in an object-oriented environment, focusing on the implementation of asynchronous methods. (Published 1999.05.00)
• Programming Java Threads in the Real World, Part 9 - Discussion of two more architectural solutions to threading problems: a synchronous dispatcher (or 'reactor') and an asynchronous dispatcher (or 'active object'). (Published 1999.06.00)
• Safe construction techniques - Concurrent programming in Java applications is more complicated than it looks: there are several subtle (and not so subtle) ways to create data races and other concurrency hazards in Java programs. In this article, Brian Goetz looks at a common threading hazard: allowing the this reference to escape during construction. (Published 2002.06.00)
• Singletons with Needles and Thread - Presents two approaches to creating thread-safe singletons. (Published 2002.01.25)
• Thread Pools and Work Queues - Explores the motivations for thread pools, some basic implementation and tuning techniques, and some common hazards to avoid. (Published 2002.07.00)
• Threading Lightly: Exploiting ThreadLocal to Enhance Scalability - Examines ThreadLocal and offers tips for exploiting its power. By Brian Goetz. (Published 2001.10.16)
• Threading Lightly: Reducing Contention - Explains why contended synchronization is a problem and then explores several techniques for reducing contention, and hence improving scalability. (Published 2001.09.05)
• Threading Lightly: Synchronization is not the Enemy - Takes a look at the semantics and the performance penalty of Java's synchronized keyword. By Brian Goetz. (Published 2001.07.17)
• Warning! Threading in a Multiprocessor World - 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. (Published 2001.02.00)
• Writing Multithreaded Java Applications - Introduces the Java Thread API, outlines issues involved in multithreading, and offers solutions to common problems. By Alex Roetter. (Published 2001.02.01)

	The "Double-Checked Locking is Broken" Declaration URL: http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html ODP description: 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.
	Thread Synchronization in Java URL: http://www.sws.bfh.ch/~fischli/threads/ ODP description: Producer Consumer, Dining Philosophers, Reader Writer problems. Applet demonstration, design diagram. Source code accessible by e-mail request. Page title: Thread Synchronization
	Simple Java Thread Management Library (SJT.Mgmt) URL: http://simplethread.sourceforge.net/ ODP description: An easy to use library for adding thread management in Java applications. The library comes from early experience with JServ's lack of thread management, and recent posts to the java developer forums. [Open source] Page title: index
	Thread Synchronization in Java (Sources) URL: http://devcentral.iticentral.com/articles/Java/thread_sync/code.html ODP description: Introduces basic concurrency problems and shows how to solve them by using builtin Java synchronization primitives. (Only sources free accessed without registration) Page title: DevCentral - - Thread Synchronization in Java Code
	Implementing Read-Write Locks in Java URL: http://www.asingh.net/technical/rwlocks.html ODP description: Read-write locks allow multiple threads to acquire a read lock provided no other thread currently has a write lock on the same object. A thread can acquire a write lock if no other thread owns either a read lock or a write lock. Page title: Read/Write Locks in Java by Amandeep Singh
	Extending Java to Support Shared Resource Protection and Deadlock Detection in Threads Programming URL: http://www.acm.org/crossroads/xrds4-2/dynac.html ODP description: The current Java thread specification does not adequately provide for the protection of shared resources or for deadlock detection. A model is introduced and implemented that can provides shared resource protection and deadlock detection. (ACM Crossroads) Page description: Extension of Java threads for shared resource protection and deadlock detection; ACM Crossroads 4-2
	Concurrent Programming with Java Lab URL: http://astha.8m.net/CPwJ/index.html ODP description: Lab. manual by Astha Ekadiyanto. Page title: Concurrent Programming with Java Lab-Manual
	Seminar: Concurrent Programming in Java URL: http://www.angelikalanger.com/Courses/ConcurrentJava.htm ODP description: A course covering all aspects of multi-thread programming in Java from plain synchronization over Java 5.0 concurrency utilities to memory model issues. Page title: Concurrent Java