//code from lecture slides
const int numReaders = 10;
const int numWriters = 5;
const int M = 3;
semaphore z, turn, mutex1, mutex2, lock;
semaphore lag;
int readers, writers;

void reader(int x){
	while(1){
		wait(z);
		wait(lag);//added delay
		wait(turn);
		wait(mutex1);
		readers++;
		if(readers == 1){
			wait(lock);
		}
		signal(mutex1);
		signal(turn);
		signal(lag);//added delay
		signal(z);
		cout <<"Reader # "<< x <<" reading\n";
		wait(mutex1);
		readers--;
		if(readers==0){
			signal(lock);
		}
		signal(mutex1);
	}
}

void writer(int y){
	while(1){
		wait(mutex2);
		writers++;
		if(writers==1){
			wait(turn);
		}
		signal(mutex2);
		wait(lock);
		cout <<"Writer # "<< y <<" writing\n";
		signal(lock);
		wait(mutex2);
		writers--;
		if (writers==0){
			signal(turn);
		}
		signal(mutex2);
	}
}

void main(){
	int i;
	initialsem(z,1);
	initialsem(mutex1,1);
	initialsem(mutex2,1);
	initialsem(lock,1);
	initialsem(turn,1);
	initialsem(lag,M);
	readers = 0;
	writers = 0;
	cobegin	{
		for (i = 1; i <=numWriters ; i ++){
			reader(i);
			writer(i);
		}
		for( i = numReaders - numWriters +1 ; i <=numReaders ; i++)
			reader(i);
	}
}