I wrap code that changes things within a call to atomic,
which prevents the thread from switching in the middle of it. That solves the problem of two threads trying to modify an object at the same time. I don't add any protections against e.g. the host machine's power being shut off in the middle of writing a file, though maybe MzScheme does.
The answer to your specific question, though, is that I wouldn't try. News isn't written like banking software.
The answer to your specific question, though, is that I wouldn't try. News isn't written like banking software.