//Global Variables//
semaphore full, full2, full3;

semaphore mutex, mutex2, mutex3;
semaphore IOREQ, reqservice, requestpending, physicalIO, OP_COMPLETE;
semaphore print;

int ID=1, B_ID=0;

int ADDR, B_ADDR=0, D_ADDR=0, seek=0;
int IORQ_ID[5];
int IORQ_ADDR[5];



int k=0, m=0;




void User()
{
int count1;
for(count1=0;count1<10;count1++){
ADDR=random(200);
p(full);
p(mutex);
B_ID=ID;
B_ADDR=ADDR;
v(mutex);
p(print);
cout << "User 1 Executes system call SIO or DOIO" <<endl;
v(print);
v(IOREQ);
p(reqservice);

}

}







void DOIO()
{
//Variables//
int Temp_ID;
int Temp_ADDR;

int buffersize=5;
int count2;


for(count2=0;count2<10;count2++){
p(IOREQ);
p(mutex);
Temp_ID=B_ID;
Temp_ADDR=B_ADDR;
    v(mutex);
    v(full);
p(full2);
p(mutex2);
k=(k+1)%5;
IORQ_ID[k]=Temp_ID;
IORQ_ADDR[k]=Temp_ADDR;
v(mutex2);
p(print);
cout << "DOIO assembles IORB and inserts it in IORQ" << endl;
v(print);
v(requestpending);

}
}











//Consumer
void Driver()
{
//Variables//
int buffersize=5;
int Temp2_ID, Temp2_ADDR;
int count3;

for(count3=0;count3<10;count3++){
p(requestpending);
p(mutex2);
m=(m+1)%5;
Temp2_ID=IORQ_ID[m];
Temp2_ADDR=IORQ_ADDR[m];
v(mutex2);
v(full2);
p(print);
cout << "Driver initiates I/O operation for user 1" << endl;
v(print);

p(full3);
p(mutex3);
D_ADDR=Temp2_ADDR;
    v(mutex3);
    v(physicalIO);
p(OP_COMPLETE);
v(reqservice);

}
}





void Disk()
{
int count4,seek_count;

for(count4=0;count4<10;count4++){
p(physicalIO);
p(mutex3);
seek=D_ADDR;
v(mutex);
v(full3);

for(seek_count=1; seek_count<seek; seek_count++)
{
}

p(print);
cout << "Disk Completes I/O operation (disk does not know what process initiated the I/O operation)" << endl;
v(print);
v(OP_COMPLETE);
p(print);
cout << "Driver signal user 1 (operation complete)" << endl;
v(print);
}
}








void main()
{

    initialsem(mutex,1);
    initialsem(mutex2,1);
    initialsem(mutex3,1);
    initialsem(full,1);
    initialsem(full2,5);
    initialsem(full3,1);
    initialsem(IOREQ,0);
    initialsem(reqservice,1);
    initialsem(requestpending,0);
    initialsem(physicalIO,0);
    initialsem(OP_COMPLETE,1);
    initialsem(print,1);

    cobegin
{

        User();
        DOIO();
        Driver();
        Disk();


}

}