Question

Placing a data item into the buffer takes 10 ms when executed in isolation. Similarly, the removal of a data item takes 10 ms. (Assume that the quantum Q is much smaller than the time to execute the CS.)

1)
When the producer and the consumer run concurrently on one CPU and the producer begins filling the buffer at time t, the consumer will finish emptying the buffer at time _____.
t + 10
t + 20
t + 40

Answer 1

Running concurrently, if the buffer holds one item, the consumer will finish emptying it at time t + 20 ms after one cycle, provided that placing and removing take 10 ms each and strictly alternate.

Step-by-step explanation:

When the producer and the consumer run concurrently on one CPU, and considering that placing and removing a data item each takes 10 ms, the total time for the consumer to finish emptying the buffer when the producer begins filling it at time t depends on the context of the buffer's capacity and the rates of production and consumption. If the buffer can hold only one item, and the producer and consumer are strictly alternating their operations due to concurrent execution, the consumer will finish one cycle of emptying right after the producer finishes one cycle of filling, which would take 20 ms in total (10 ms for producing and 10 ms for consuming).

Thus, if the buffer starts empty and we are only considering one cycle of production and consumption, the consumer will finish emptying the buffer at time t + 20 ms. However, without additional information about how many cycles of production and consumption need to be completed or the buffer capacity, we cannot accurately extend this to multiple cycles. If there are multiple cycles, and if the consumer is able to start consuming right after the producer fills the buffer, then after each cycle, there would be an additional 20 ms added for each cycle completed.