}
}
-static void
+/*
+ * This function contains the main program loop, listening for replies to pings
+ * sent from the signal-driven pinger().
+ */
+void
get_response(void)
{
- fd_set rfds;
- int retval, maxd = -1;
- struct host_entry * p;
-
- while (1) {
- p = first_host_in_list;
+ while (true) {
+ fd_set rfds;
FD_ZERO(&rfds);
- while (p) {
- if (p->socket != -1) {
- if (p->socket > maxd) maxd = p->socket;
- FD_SET(p->socket, &rfds);
- }
- p = p->next;
+
+ assert(first_host_in_list);
+ struct host_entry * host = first_host_in_list;
+
+ int max_fd = -1;
+ while (host) {
+ if (host->socket > max_fd) max_fd = host->socket;
+ FD_SET(host->socket, &rfds);
+ host = host->next;
}
- retval = select(maxd+1, &rfds, NULL, NULL, NULL);
- if (retval < 0) {
- /* Intentionally empty. We arrive here when interrupted by a signal. No action should be taken. */
- } else {
- if (retval > 0) {
- p = first_host_in_list;
- while (p) {
- if (p->socket!=-1 && FD_ISSET(p->socket, &rfds)) read_icmp_data(p);
- p = p->next;
- }
- } else {
- /* TODO: How to handle this error? */
+ int retval;
+ if ((retval = select(max_fd+1, &rfds, NULL, NULL, NULL)) > 0) {
+ assert(first_host_in_list);
+ host = first_host_in_list;
+ while (host) {
+ if (FD_ISSET(host->socket, &rfds)) read_icmp_data(host);
+ host = host->next;
}
+ } else {
+ /* An error or interruption occurred. */
+ /* We can't do anything about it, so loop and try again. */
}
}
}