Since I found no message mentioning thread-safety, here some hints:

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Warning: about 15% of the recipes functions are not thread-safe
this means they will produce incorrect results when used in a multithread environment, or even lead to execution errors/core dumps.
not thread-safe: static variables
not thread-safe: global variables (defined outside of function body, eventually referenced by external declarations)
sometimes you may not need thread-safety, as perhaps might be the case with the random number generators "ran1..4".
If you need thread-safety in these cases, you will have to rewrite the functions.
it would be nice if in future a thread-safe version of the NR would be offered.
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