Pass arguments through NIO_Selector_synchronized() as an on-stack array
Pass arguments through NIO_Selector_synchronized() as an on-stack array

NIO_Selector_synchronized() takes a callback to a C function to be
called with the selector mutex held. Previously I was passing arguments
through this function in the form of garbage collected Ruby arrays.
Gross!

The new implementation uses on-stack C arrays. Muuch better!

frsyuki/nio4r,celluloid/nio4r,celluloid/nio4r,marshall-lee/nio4r,marshall-lee/nio4r,celluloid/nio4r,frsyuki/nio4r,tpetchel/nio4r,tpetchel/nio4r,tpetchel/nio4r,frsyuki/nio4r,marshall-lee/nio4r