Explain Busy Waiting Semaphores
Weak, Busy-wait Semaphores
a) The simplest way to implement semaphores.
b) Useful while critical sections last for a short time, or we comprise lots of CPUs.
c) S initialized to positive value (to permit someone in at the beginning).
d) S is an integer variable that, aside from initialization, can only be accessed by 2 atomic and mutually exclusive operations:
wait(s):
while (s.value != 0);
s.value--;
signal(s):
s.value++;
All happens atomically that is wrap pre and post protocols.