non-blocking read/write

[ssfrr]

Currently reading or writing from a LibSndFile stream blocks all of Julia because it uses libsndfile's read and write functions. If we could do the read/write in a separate thread and then notify an AsyncCondition condition, the Julia Task could just wait on the condition. Not sure if that could be done in pure Julia or if I'd need a little C shim, but that wouldn't be so bad...

[ssfrr]

It seems that @threadcall is designed for exactly this use-case.

edit: Whoops, according to stefan it looks like as of Julia 1.3 @spawn is the way to go.