PROCESS SYNCHRONIZATION

Experiment Number 1 : Counting Semaphores



Algorithm

• Step 1: Let entity access a critical condition.


• Step 2: Entity executes wait (P) in binary semaphore.


• Step 3: Semaphore checks integer value

If integer value=0, Semaphore places entity in Semaphore’s queue.

Entity waits and then Semaphore provides access unit to entity.

If integer value!=0, Semaphore decrements integer value by one.

Then Semaphore provides access unit to entity.


• Step 4: Entity access critical section & executes on it.


• Step 5: Entity executes signal(V) in binary semaphore.


• Step 6: Entity leaves critical section.