Time Travel Debugging

Greg Law

⏱ 90 minute session

beginner

intermediate

advanced

16:00-17:30, Friday, 19th April 2024

Everyone knows that debugging is twice as hard as writing the code in the first place. At some point your program, which did billions of things per second, has diverged from your expectations and you need to figure out where. Time travel debugging is incredibly powerful: it allows you to rewind your program's execution to any line of code that executed and see any piece of program state at any time. Setting a watchpoint (aka data breakpoint) on a suspicious-looking data and winding back to the line of code that last changed that data is particularly helpful.

For decades time travel debuggers have been toys, but now they're here for real. The latest breed (RR, TTD LiveRecorder and others), have good performance and scale well to real-world, complex code. This talk will show demos of different tools on different platforms and get "under the hood" to explain how they work so that you can choose the best one for you and get the most out of it.

🏷 debugging

🏷 tools

Greg Law

Greg is the founder of undo.io. He is a coder at heart, but likes to bridge the gap between the business and software worlds.

Greg has 25 years’ experience in the software industry and has held development and management roles at companies including the pioneering British computer firm Acorn, as well as fast-growing start ups, NexWave and Solarflare. It was at Acorn that Greg met Julian and on evenings and weekends, they invented the time-travel technology that would become the basis of Undo that is used today by developers at the world's leading tech companies to help them understand and root cause the most complex bugs -- as well as the day-to-day stuff.

Greg lives in Cambridge, UK with his wife, two teenagers, two dogs and two cats. In his spare time, he catches up on email.