int init(void) /* initialize the simulator */
{
int i;
float sum, avg;
float jimsrand();
printf("----- Stop and Wait Network Simulator Version 1.1 -------- \n\n");
printf("Enter the number of messages to simulate: ");
scanf_s("%d",&nsimmax);
printf("Enter packet loss probability [enter 0.0 for no loss]:");
scanf_s("%f",&lossprob);
printf("Enter packet corruption probability [0.0 for no corruption]:");
scanf_s("%f",&corruptprob);
printf("Enter average time between messages from sender's layer5 [ > 0.0]:");
scanf_s("%f",&lambda);
printf("Enter TRACE:");
scanf_s("%d",&TRACE);
srand(9999); /* init random number generator */
sum = 0.0; /* test random number generator for students */
for (i=0; i<1000; i++)
sum=sum+jimsrand(); /* jimsrand() should be uniform in [0,1] */
avg = (float)(sum/1000.0);
if (avg < 0.25 || avg > 0.75) {
printf("It is likely that random number generation on your machine\n" );
printf("is different from what this emulator expects. Please take\n");
printf("a look at the routine jimsrand() in the emulator code. Sorry. \n");
return -9;
}
ntolayer3 = 0;
nlost = 0;
ncorrupt = 0;
time=0.0; /* initialize time to 0.0 */
generate_next_arrival(); /* initialize event list */
return 0;
}
int main()
{
struct event *eventptr;
struct msg msg2give;
struct pkt pkt2give;
int i,j;
init();
A_init();
B_init();
while (1) {
eventptr = evlist; /* get next event to simulate */
if (eventptr==NULL)
goto terminate;
evlist = evlist->next; /* remove this event from event list */
if (evlist!=NULL)
evlist->prev=NULL;
if (TRACE>=2) {
printf("\nEVENT time: %f,",eventptr->evtime);
printf(" type: %d",eventptr->evtype);
if (eventptr->evtype==0)
printf(", timerinterrupt ");
else if (eventptr->evtype==1)
printf(", fromlayer5 ");
else
printf(", fromlayer3 ");
printf(" entity: %d\n",eventptr->eventity);
}
time = eventptr->evtime; /* update time to next event time */
//if (nsim==nsimmax)
//break; /* all done with simulation */
if (eventptr->evtype == FROM_LAYER5 ) {
if(nsim < nsimmax -1)
generate_next_arrival(); /* set up future arrival */
/* fill in msg to give with string of same letter */
j = nsim % 26;
for (i=0; i<20; i++)
msg2give.data[i] = 97 + j;
if (TRACE>2) {
printf(" MAINLOOP: data given to student: ");
for (i=0; i<20; i++)
printf("%c", msg2give.data[i]);
printf("\n");
}
nsim++;
if (eventptr->eventity == A)
A_rdtsend(msg2give);
else
B_rdtsend(msg2give);
}
else if (eventptr->evtype == FROM_LAYER3) {
pkt2give.seqnum = eventptr->pktptr->seqnum;
pkt2give.acknum = eventptr->pktptr->acknum;
pkt2give.checksum = eventptr->pktptr->checksum;
for (i=0; i<20; i++)
pkt2give.payload[i] = eventptr->pktptr->payload[i];
if (eventptr->eventity ==A) /* deliver packet by calling */
A_rdtrcv(pkt2give); /* appropriate entity */
else
B_rdtrcv(pkt2give);
free(eventptr->pktptr); /* free the memory for packet */
}
else if (eventptr->evtype == TIMER_INTERRUPT) {
if (eventptr->eventity == A)
A_timerinterrupt();
else
B_timerinterrupt();
}
else {
printf("INTERNAL PANIC: unknown event type \n");
}
free(eventptr);
}
terminate:
printf(" Simulator terminated at time %f\n after sending %d msgs from layer5\n",time,nsim);
return 0;
}
int main(int argc, char **argv)
{
struct event *eventptr;
struct msg msg2give;
struct pkt pkt2give;
int i,j;
char c;
int opt;
int seed;
//Check for number of arguments
if(argc != 5){
fprintf(stderr, "Missing arguments\n");
printf("Usage: %s -s SEED -w WINDOWSIZE\n", argv[0]);
return -1;
}
/*
* Parse the arguments
* http://www.gnu.org/software/libc/manual/html_node/Example-of-Getopt.html
*/
while((opt = getopt(argc, argv,"s:w:")) != -1){
switch (opt){
case 's': if(!isNumber(optarg)){
fprintf(stderr, "Invalid value for -s\n");
return -1;
}
seed = atoi(optarg);
break;
case 'w': if(!isNumber(optarg)){
fprintf(stderr, "Invalid value for -w\n");
return -1;
}
WINSIZE = atoi(optarg);
break;
case '?': break;
default: printf("Usage: %s -s SEED -w WINDOWSIZE\n", argv[0]);
return -1;
}
}
init(seed);
A_init();
B_init();
while (1) {
eventptr = evlist; /* get next event to simulate */
if (eventptr==NULL)
goto terminate;
evlist = evlist->next; /* remove this event from event list */
if (evlist!=NULL)
evlist->prev=NULL;
if (TRACE>=2) {
printf("\nEVENT time: %f,",eventptr->evtime);
printf(" type: %d",eventptr->evtype);
if (eventptr->evtype==0)
printf(", timerinterrupt ");
else if (eventptr->evtype==1)
printf(", fromlayer5 ");
else
printf(", fromlayer3 ");
printf(" entity: %d\n",eventptr->eventity);
}
time_local = eventptr->evtime; /* update time to next event time */
if (nsim==nsimmax)
break; /* all done with simulation */
if (eventptr->evtype == FROM_LAYER5 ) {
generate_next_arrival(); /* set up future arrival */
/* fill in msg to give with string of same letter */
j = nsim % 26;
for (i=0; i<20; i++)
msg2give.data[i] = 97 + j;
if (TRACE>2) {
printf(" MAINLOOP: data given to student: ");
for (i=0; i<20; i++)
printf("%c", msg2give.data[i]);
printf("\n");
}
nsim++;
if (eventptr->eventity == A)
A_output(msg2give);
else
B_output(msg2give);
}
else if (eventptr->evtype == FROM_LAYER3) {
pkt2give.seqnum = eventptr->pktptr->seqnum;
pkt2give.acknum = eventptr->pktptr->acknum;
pkt2give.checksum = eventptr->pktptr->checksum;
for (i=0; i<20; i++)
pkt2give.payload[i] = eventptr->pktptr->payload[i];
if (eventptr->eventity ==A) /* deliver packet by calling */
A_input(pkt2give); /* appropriate entity */
else
B_input(pkt2give);
free(eventptr->pktptr); /* free the memory for packet */
}
else if (eventptr->evtype == TIMER_INTERRUPT) {
if (eventptr->eventity == A)
A_timerinterrupt();
else
B_timerinterrupt();
}
else {
printf("INTERNAL PANIC: unknown event type \n");
}
free(eventptr);
}
terminate:
//Do NOT change any of the following printfs
printf(" Simulator terminated at time %f\n after sending %d msgs from layer5\n",time_local,
nsim);
printf("\n");
printf("Protocol: GBN\n");
printf("[PA2]%d packets sent from the Application Layer of Sender A[/PA2]\n", A_application);
printf("[PA2]%d packets sent from the Transport Layer of Sender A[/PA2]\n", A_transport);
printf("[PA2]%d packets received at the Transport layer of Receiver B[/PA2]\n", B_transport);
printf("[PA2]%d packets received at the Application layer of Receiver B[/PA2]\n",
B_application);
printf("[PA2]Total time: %f time units[/PA2]\n", time_local);
printf("[PA2]Throughput: %f packets/time units[/PA2]\n", B_application/time_local);
return 0;
}
