True, add_buffer's thread-safety is of little to no consequence as it's not what makes things slow. I'd be interested in what other functions are thread-safe. Your (JustSid's) example is great, but it'd be nice to be able to just use file_load in another thread, for example (as the add_buffer example in the manual shows).
Just for your undrstanding: File_Load only reads a complete file from harddisk and stores it into the memory.. as long as the method does not contain any strange references to engine-functions they should be thread-safe..
And even if not: Just read the file by yourself via fopen/fread/fclose (methods which are threads safe)
