1) Implement a counting semaphore using binary semaphores.

Hint: Use two binary semaphores and an integer variable: use the integer

variable as the integer variable in the counting semaphore; use the first

binary semaphore as a mutex lock while updating the integer variable; use

the second binary semaphore to block/unblock the process depending on

the integer variable value

* Binary semaphore: A binary semaphore acts like a mutex lock. Its

definition is shown below.

wait(S){

while(S<=0)

; // busy wait

S;

}

signal(S){

if(S==0)

S++;

}