Deadlock in Unit Tests

[jzampieron]

I am able to get unit tests which use the wrapper to deadlock on startup.

It seems to be worse on x86-64 and somehow seems to work on aarch64, but this could be a timing thing.

Best I can tell the rust test execution runtime is violating the libxml2 initialization requirement.

Reference:

• https://dev.w3.org/XInclude-Test-Suite/libxml2-2.4.24/libxml2-2.4.24/doc/threads.html
• A new thread is created for each test even if --test-threads=1 rust-lang/rust#104053

Uncertain if this is even fixable in rust-libxml or just needs to be a known issue and documented.

I'm still new-enough to Rust that IDK if replacing INIT_LIBXML_PARSER with a OnceLock instead of a Once would do it.

[dginev]

What are the conditions to reproduce the deadlock? I am on a x86-64 system and the latest master seems to pass tests without issues over here with both stable and nightly Rust.

[jzampieron]

Sorry for the pretty thin bug report. Was late yesterday. I'll try to work up a minimum reproduce code example (can't post the actual for proprietary reasons) with directions for use.

May take a couple days.

[jzampieron]

Here's a full reproduction on my Mac Host.

https://github.com/jzampieron/rust-libxml-190

Code using the library. Example XML test files and steps to reproduce inside a docker container.