void char_ready_handler(int signo, siginfo_t* siginfo, void *dummy) {
char answer;
Tmeas *temp = (Tmeas*)(((struct aiocb*)siginfo->si_value.sival_ptr)->aio_buf);
int ptemp = ((struct aiocb*)siginfo->si_value.sival_ptr) - &aiocb[0];
int intemp = (int)(((struct aiocb*)siginfo->si_value.sival_ptr)->aio_fildes);
if (aio_error(((struct aiocb*)siginfo->si_value.sival_ptr)) != 0)
printf("ERROR\n");
if( signo == SIGIO ) {
/* printf("i/o complete signal is received. Char was %d \n",
*((struct Tmeas*)(((struct aiocb*)siginfo->si_value.sival_ptr)->aio_buf)))->value;
//start a new read*/
clock_gettime(CLOCK_REALTIME, ¤t_time);
lag = diff_timespec(¤t_time, &temp->moment );
printf("# Measurement value of %d sensor is %d, it took %d\n",
ptemp+1, temp->value, lag.tv_nsec);
increment_timespec(&total_lag, &lag);
if (aio_return(((struct aiocb*)siginfo->si_value.sival_ptr)) > 0 )
aio_read(((struct aiocb*)siginfo->si_value.sival_ptr));
else
printf("-------------EOF in sensor #%d, %d remaining--------------------\n", ptemp+1, --NSENS);
}
}
int main(void) {
int retval = -1;
fd_set rfds;
int fdmax = 0;
int n = 0;
int i = 0;
int k = 0;
struct timespec sumOfDelays;
struct timespec delay;
struct timespec timeNow;
int sensorDescriptors[10];
Tmeas measurement;
int eofArray[10];
int eofCount = 0;
int counter = 0;
// Initialize struct timespec variables
memset(&sumOfDelays, 0, sizeof(sumOfDelays));
for (i = 0; i < 10; i++) {
eofArray[i] = 1;
}
// Specify 5 values per sensor
if (StartSimulator(sensorDescriptors, 5) < 0) {
fprintf(stderr, "Error: Cannot initialize sensor simulator\n");
exit(EXIT_FAILURE);
}
fdmax = findMaxFileDescriptor(sensorDescriptors, 10);
do {
FD_ZERO(&rfds);
for (i = 0; i < 10; i++) {
if (eofArray[i] != 0) // Add file descriptors that haven't reached EOF to the set
FD_SET(sensorDescriptors[i], &rfds);
}
n = select(fdmax+1, &rfds, NULL, NULL, NULL);
if (n > 0) {
for (i = 0; i < 10; i++) {
if (FD_ISSET(sensorDescriptors[i], &rfds)) {
k++;
/*
* Sensor descriptor is ready, but it is also ready on EOF
* So check for EOF condition, if EOF, then don't read it
*/
if (eofArray[i] == 0) // 0 indicates EOF condition
break;
else {
retval = read(sensorDescriptors[i], &measurement, sizeof(Tmeas));
if (retval == 0) {
eofArray[i] = 0;
eofCount++;
} else {
counter++;
}
if (clock_gettime(CLOCK_REALTIME, &timeNow) == -1) {
perror("clock gettime");
exit(EXIT_FAILURE);
}
delay = diff_timespec(&measurement.moment, &timeNow);
increment_timespec(&sumOfDelays, &delay);
}
}
// All ready file descriptors have been processed
// So it's not necessary for looping to the end of loop
if (k == n)
break;
}
k = 0;
}
} while (eofCount != 10);
// Display the total delay
printf("Sum of delay %ld s %ld ns\n", sumOfDelays.tv_sec, sumOfDelays.tv_nsec);
printf("counter %d\n", counter);
return EXIT_SUCCESS;
}
