Thread-safe validation disabling

[pabigot]

Thread-safe validation disabling

[pabigot]

PyXB wasn't designed for use in threaded applications. (Nor was it designed to operate without validation; although it turned out it was possible and useful to some people to disable validation, doing so will change the binding content in ways that may not preserve critical information).

As it turns out, though, the practical (untested) answer is yes, this can be done. Look at pyxb.ValidationConfig, which was designed to control validation behavior on a per-class (XML type/element) basis. If you modify this class to use thread-local state instead of private attributes, you can probably make this work as long as you don't create any new namespaces or change the content models while multiple threads are active.

Interesting use case. I'll consider adding thread-local state to that class in a future release, and look into what it might take to make the rest of the system thread-safe.

[pabigot]

A candidate solution is 65a3e6d. Let me know if that works for you; if so, and it survives other testing, I'll put it in the next release.

[pabigot]

On consideration, while 65a3e6d will probably do what you want, it's not really consistent with the pre-existing use of distinct configurations to control validation within the XML space, where changing a validation configuration should affect all threads. It might be possible to make the global configuration thread-local but content-specific ones global, but that could produce some really confusing/non-deterministic behavior.

This gets back to PyXB not being designed for use in a threaded environment. Retro-fitting thread safety is not trivial. At this time I think the final resolution of this issue will be "wontfix" and "don't use PyXB with multiple threads".

[pabigot]

Based on the fact you can use single-threaded execution as PyXB was designed in your commercial application, I'll just close this as "wontfix".