We've released new versions of both LID and LIA today. These releases include many changes that we've been testing with customers over the last couple of months and mainly deal with fixing hangs during the shutdown of managed applications when they are run under the tools and performance improvements when running on target processes which use a large number of locks and create a large number of lock acquisition sequences.

In addition we've fixed some bugs with TryEnterCriticalSection() where we were incorrectly reporting lock inversions when a call to TryEnterCriticalSection() returned FALSE and added a few extra command line switches so that you can show progress during lock inversion detection after the target process completes.

You can download the latest version of LID from here and all customers are being contacted via email with details of how to download the latest release of LIA.

Do continue to get in touch with comments and suggestions and any problems that you have.

Back in September 2005 I wrote a tool to help me find a deadlock in a complex multi-threaded server that I was building for a client. The tool monitored all lock acquisitions that the target program made and could indicate where lock inversions were occurring. Since any of the lock inversions could become a deadlock given the right thread interaction it was an effective deadlock detector which could report on deadlocks before they happened.

Every so often I'd pull out this tool, use it to locate a deadlock, improve it slightly and then get back to my 'real work' of building complex server systems. The tool evolved and each time that I used it to locate a deadlock, in minutes rather than days, I thought to myself that I should package it up as a product and sell it. There were always other things on the list of things to do and so it has taken until 2011 for me to launch LockExplorer.com and make the tools that I've been working on over the years available to others.

One thing that I've found amazingly useful is the ability to run my deadlock detection tools as part of my pre-release test cycle. The original deadlock detection tool took a long time to process all of the data that it was gathering about the target application's lock usage, but various performance improvements that I've made over the years now mean that I can run these tools to test high performance client/server systems without affecting the performance of the system under test that much. I then split the tool into three, a Lock Inversion Detector which runs very fast but simply tells you if there are any lock inversions detected, and a Lock Inversion Analyser which tells you exactly which lines of code are the cause of your lock inversions and the full featured Lock Explorer which allows you to navigate all of the data that the tools gather and drill down to explore how your code uses its locks.

The Lock Inversion Detector is available for free, if you run it regularly enough you may never get to the point where you need to purchase the Lock Inversion Analyser to locate your potential deadlocks. Lock Explorer is still in development, but I hope to start the beta test programme soon!