The code below contains a proposal solution to the Producer-Consumer-Problem. Assume that full is initialized to 0, and empty is initialized to the number of slots in the buffer.

a) Why does this proposed solution use 2 semaphores, empty and full, rather than just one (call it count)?

b) It is a problem if we switch the order of the two lines wait (empty) and wait (mutex) in the producer process? Justify your answer.