Solution for P/C using Semaphores

• Producer

• repeat

• produce item v;

• MUTEX.wait();

• b[in] = v;

• in = in + 1;

• MUTEX.signal();

• forever;

• What if Producer is slow or late?

• Consumer

• repeat

• while (in <= out) nop;

• MUTEX.wait();

• w = b[out];

• out = out + 1;

• MUTEX.signal();

• consume w;

• forever;

• Ans: Consumer will busy-wait at the while statement.

Previous slide

Next slide

Back to first slide

View graphic version