Writings by Allen Holub
This page contains writing by Allen Holub. Some items
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Java
Deadlock
This
article describes deadlock in Java. (A situation where
two threads are both suspended, waiting for the other to do something.)
It presents the usual sequence-related deadlock scenarios, but also
discusses a wait()-related scenario that you may not have
considered.
Two-Phase Handshakes
This article demonstrates a technique for synchronizing two threads that need to wait for each other. For example:
- A thread might create a bunch of auxiliary threads and need to wait for all of them to be up and running before continuing.
- An AWT/Swing application needs to be sure that a control is actually active on the screen before it waits for the user to enter input into the control.
- You need to write a "co-routine" that suspends a second thread between calls. [e.g. you need to shut down a SAX XML parser between calls to get_next_element()].
OO Design
The Bank-of-Allen Project
The Bank-of-Allen Project describes the object-oriented design process from requirements gathering through to use-case analysis. It discusses formal problem statements, what comprises a use case and how to organize one, and UML activity diagrams, all in the context of a real-world example.
This document started out life as a series of articles on the IBM DeveloperWorks site. Unfortunately, IBM has removed some of the articles from its site, so I've provided the full version, here. I'm fiddling with this article constantly, so the version presented here is a bit different than the original.
Design Patterns Quick Reference, Creational Patterns
This .pdf file contains the first draft of my Design-Patterns Quick Reference. This document is a two-facing-page-per-pattern reference to the complete set of Gang-of-Four design patterns. The final version of this document will be an Appendix from a forthcoming book, tentatively titled Applying Design Patterns in Java (to be published by Apress). I will be updating this document periodically; newsletter subscribers will be notified about updates.
Miscelleny
Read Andrew Schulman's review of Compiler Design in C.