C FIFO Queue

I was looking up info on implementing a FIFO queue in C and came across this code from a published book: http://www.cs.sunysb.edu/~skiena/392/programs/queue.c

Isn't this thing going to fail after you've queued QUEUESIZE times, regardless of dequeuing?

no, it sounds just like the letter Q. For example, "Johnny Dumbass needs to go back to school, and when he got there, he entered the QUEUE of people waiting to register."