2 threads are created on 2 different vcpus, one consumer and one producer.

Both threads are pushing and popping concurrently 1,000,000,000 elements,
the producer is pushing a random number between 0 and 7 and consumer pops
those numbers. Both of the threads keeps track on the values they
pushed/popped. per each value, the number of pushed elements
should be equal to the number of popped elements.

 - ring_spsc: 14.8 Mop/s per core