Revision control locking: Is the jury still out?

Question

When I\'m online it seems that everyone has agreed that using the exclusive locking workflow in source control is a Bad Thing. All the new revision control systems I see app

Answer 1

Exclusive locking is the best you can do in a worst-case scenario, so its presence always tells me that there are bigger problems.

One of those bigger problems is bad organization of code. On one of my consulting gigs for a major telecomm, eight out of thirty team members were constantly working on the same source file (a VB.NET "god" form). We would wait for someone else to finish their work and release the exclusive lock (VSS), then the next person in the pecking order would immediately lock the file to apply their changes. This took forever because they had to reintegrate all their work into the new code that they could see only just then. Since I was the new guy, I was on the bottom of the pecking order and I NEVER was allowed to check in my code changes. I eventually went to the project manager/director and suggested that I be tasked with another part of the application functionality. This project eventually self-destructed, but most of us left as we realized that inevitability. Note that the use of VSS integration was a crucial part of this failure, too, since it forces early acquisitions of that precious file lock.

So, a well-organized project should almost never result in two people working on the same part of the same source file at the same time. Therefore, no need for exclusive locking.

Another of those bigger problems is putting binary files into source control. Source control tools are not designed to handle binaries, and that is a good thing. Binaries require different treatment, and source control tools cannot support that special treatment. Binaries must be managed as a whole, not as parts (lines). Binaries tend to be far more stable/unchanging. Binaries tend to need explicit versioning different from source control versioning, often with multiple versions available simultaneously. Binaries are often generated from source, so only the source needs to be controlled (and the generation scripts). See Maven repositories for a binary-friendly storage design (but please don't use Maven itself, use Apache Ivy).