Consider the following two threads, to be run concurrently in a shared memory (all variables are shared between the two threads). Thread A Thread B for i = 1 to 5 do for j = 1 to 5 do x = x + 1; x = x - 1;

Initially, x = 5. Assume that the code runs on a single-processor system on which load and store instructions are atomic. Also, x must first be loaded into a register before being incremented and stored back to memory afterwards.

Q: Enumerate all the possible values for x after both threads have completed? Explain your reasoning and show example sequences of instruction executions that would produce the result in your answer.