Thread safety is not the issue here...that usually relates to how the library has been implemented (ie using static buffers for multiple threads or relating a buffer to a specific thread)......
Originally posted by Speedy5
I don't think its possible but check your library's documentation. They should be labeled "thread-safe" or "not thread-safe." If they're not labeled at all, best bet on that its not since the developers didn't have threads in mind when making it. Most of the C/C++ library is not-thread safe as they only suggest one thread being executed (UNIX style I guess, one thread per process).