[xml] multithreading issue?

[<oliverst online de>]

I recognised, that some functions in the libxml2 are calling
xmlInitParser(). Isn't this function supposed to be called before the
parser is being used? And wouldn't there be a multithreading issue with
it, because xmlInitParser() isn't reentrant? 
Think of a multithreaded program, that calls multiple function witha
xmlInitParser() from differnet threads. It would surely call
xmlInitParser() more than once.