From d3f3ee16d8adaef681afed67f236e3bb14e7cdc0 Mon Sep 17 00:00:00 2001
From: Joel Grunbaum <joelgrun@gmail.com>
Date: Wed, 21 Oct 2020 13:05:26 +0000
Subject: [PATCH] change artifact name and added penalty for failed connections
---
main.c | 97 ++++++++++++++++++++++++++++++++++++------------
1 files changed, 72 insertions(+), 25 deletions(-)
diff --git a/main.c b/main.c
index 3db7eee..5fb4cf2 100644
--- a/main.c
+++ b/main.c
@@ -1,29 +1,43 @@
+/**
+ * A basic dns benchmark testing program
+ * Tests servers in parallel so reasonably fast
+ * Tried to only use POSIX functions to ensure cross platform compatibility
+ **/
+
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <time.h>
+#include <pthread.h>
#include "dns.h"
#include "servers.h"
#include "slist.h"
#define NUM_TESTS 10
-int test_dns(struct dns_list *dnss, struct hosts_list *hosts, int num_hosts, int num_tests);
-struct timespec test_server(struct dns_list *dns, struct hosts_list *hosts, int num_hosts, int num_tests);
+int test_dns(void);
+void *test_server(void *in);
+void *print_progress(void *in);
+
+// All global variables as passing to threads in structs caused corruption
+// Variables are only modified before threads are created and as such are thread-safe
+// tests_done is modified to provide a rough count of number of tests being completed for progress measurement
+int tests_done = 0, num_tests = NUM_TESTS, num_servers = NUM_DNS, num_hosts = 0;
+struct hosts_list *hosts = NULL;
+struct dns_list *servers = NULL;
int main(int argc, char** argv)
{
- int option, num_hosts = 0, added_hosts = 0, num_tests = NUM_TESTS;
- struct hosts_list *servers_hosts = NULL;
- struct dns_list *servers_dns = NULL;
+ int option, added_hosts = 0;
while((option = getopt(argc, argv, "s:h:t:n:")) != -1) {
switch (option) {
case 's': //server to use
- add_dns_server(&servers_dns, optarg);
+ add_dns_server(&servers, optarg);
+ num_servers++;
break;
case 'h': //hostname to search
- add_hosts_server(&servers_hosts, optarg);
+ add_hosts_server(&hosts, optarg);
added_hosts++;
break;
case 't': //set number of hosts to test
@@ -35,8 +49,8 @@
case '?':
default:
printf("Error: invalid option -%c\n", optopt);
- free_dns_list(&servers_dns);
- free_hosts_list(&servers_hosts);
+ free_dns_list(&servers);
+ free_hosts_list(&hosts);
exit(1);
}
}
@@ -44,52 +58,85 @@
num_hosts = NUM_HOSTNAMES + added_hosts;
}
for (int i = added_hosts; i < num_hosts; i++) {
- add_hosts_server(&servers_hosts, HOSTNAMES[i-added_hosts]);
+ add_hosts_server(&hosts, HOSTNAMES[i-added_hosts]);
}
for (int i = 0; i < NUM_DNS; i++) {
- add_dns_server(&servers_dns, DNS_SERVERS[i]);
+ add_dns_server(&servers, DNS_SERVERS[i]);
}
- test_dns(servers_dns, servers_hosts, num_hosts, num_tests);
- sort_servers(&servers_dns);
- print_servers(servers_dns);
- free_dns_list(&servers_dns);
- free_hosts_list(&servers_hosts);
+ test_dns();
+ sort_servers(&servers);
+ print_servers(servers);
+ free_dns_list(&servers);
+ free_hosts_list(&hosts);
return 0;
}
-int test_dns(struct dns_list *dnss, struct hosts_list *hosts, int num_hosts, int num_tests)
+// Test each dns server individually
+// Each test runs in its own thread and results are written to the respective dns_list
+int test_dns(void)
{
- struct dns_list *curr = dnss;
+ struct dns_list *curr = servers;
+ int i = 0;
+ pthread_t *threads = malloc(num_servers*sizeof(pthread_t));
+ pthread_t progress;
+ pthread_create(&progress, NULL, print_progress, NULL);
while (curr) {
- test_server(curr, hosts, num_hosts, num_tests);
+ pthread_create(&threads[i], NULL, test_server, (void*)curr);
curr = curr->next;
+ i++;
}
+ for (int i = 0; i < num_servers; i++) {
+ pthread_join(threads[i], NULL);
+ }
+ pthread_cancel(progress);
+ printf("\r100.00%% done\n");
+ free(threads);
return 0;
}
-struct timespec test_server(struct dns_list *dns, struct hosts_list *hosts, int num_hosts, int num_tests)
+// Tests an individual dns server with all the hostnames configured
+void *test_server(void *in)
{
unsigned long long avg_nsec = 0;
+ struct dns_list *dns = (struct dns_list *)in;
dns->time.tv_sec = 0; dns->time.tv_nsec = 0;
for (int i = 0; i < num_tests; i++) {
struct hosts_list *curr = hosts;
while (curr) {
struct timespec run;
+ run.tv_sec = -1; run.tv_nsec = 0;
unsigned char buf[65536];
- run = resolve(buf, curr->server, dns->server, T_A);
- if (run.tv_sec == -1)
- continue;
+ for (int i = 0; i < 3 && run.tv_sec == -1; i++) {
+ run = resolve(buf, curr->server, dns->server, T_A);
+ }
+ if (run.tv_sec == -1) //if test has failed 3 times, set time taken to 3s as penalty
+ run.tv_sec = 3;
dns->time.tv_sec += run.tv_sec;
dns->time.tv_nsec += run.tv_nsec;
- if (dns->time.tv_nsec >= 1000000000) {
+ if (dns->time.tv_nsec >= 1000000000) { //nanoseconds have overflowed into seconds
dns->time.tv_sec += 1;
dns->time.tv_nsec -= 1000000000;
}
+ tests_done++;
curr = curr->next;
}
}
avg_nsec = 1000000000*(dns->time.tv_sec%(num_hosts*num_tests))+dns->time.tv_nsec;
dns->time.tv_sec = dns->time.tv_sec/(num_hosts*num_tests);
dns->time.tv_nsec = avg_nsec/(num_hosts*num_tests);
- return dns->time;
+ return NULL;
+}
+
+// Prints the progress every 0.1s for an indication of speed
+// tests_done is being written to in parallel, so may be overwritten but serves as a decent estimate of the progress
+void *print_progress(void *in)
+{
+ struct timespec s;
+ s.tv_sec = 0; s.tv_nsec = 100000000;
+ while (1) {
+ printf("\r%.2f%% done", ((float)tests_done)/(num_servers*num_hosts*num_tests) * 100);
+ fflush(stdout);
+ nanosleep(&s, NULL);
+ }
+ return NULL;
}
--
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