Comment 7 for bug 856072

(In reply to Patrick McManus from comment #5)
> > I don't see a way to skip that
>
> One thing we could do would be to cache the contents of the file in ram in a
> read-only threadsafe buffer. Update it under lock for the same conditions we
> call res_ninit() right now.
>
> A slightly uglier approach would be to just put a lock around
> _files_get_addrinfo. If STDIO is really not threadsafe (independent of file)
> couldn't either of these still have races against the content process saving
> a download, for instance? Or is the issue that all the threads are reading
> /etc/hosts?

Hm, good point; actually stdio is not thread-safe in general :(

There might be other race conditions, but the one I found happens when allocating FILE handles: (the netbsd code had locks but they were removed in the android fork; boo)
https://github.com/android/platform_bionic/blob/master/libc/stdio/findfp.c#L95

So in theory, even if we lock getaddrinfo, we could race against other stdio usages.

> Either way means pretty much importing the c file you referenced and calling
> that version of getaddrinfo on android < honeycomb, but that actually looks
> relatively easy to do to me. (almost everything in there is static, so just
> drag it along and make the necessary changes).

Thanks for the ideas!