On windows especially i/o is usually async, the sync apis serialize all the i/o on the file object(even across threads). It has weird consequences, e.g. you ca

On windows especially i/o is usually async, the sync apis serialize all the i/o on the file object(even across threads). It has weird consequences, e.g. you can't use a named pipe in 2 threads doing read, write separately(without doing protcol level coordination say in a proxy). You need to use asynchornous i/o to get it right.