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/* check that the delay we setup is respected */
#include "common.h"
#include "../utils.h"
#include <poll.h>
static unsigned test_num = 0;
static int udp_socks[2] = { -1, -1 };
static const char payload_id[8] = "DELAY\0\0";
typedef struct {
char id[8];
unsigned test_num;
uint64_t time;
} test_payload;
static void
wait_reply(int sock, test_payload *payload)
{
struct pollfd fds[1];
for (;;) {
// wait a packet or bail out on timeout
fds[0].fd = sock;
fds[0].events = POLLIN;
fds[0].revents = 0;
int res = poll(fds, 1, 1000);
assert(res == 1);
// check packet received is what we expect
if (recv(sock, payload, sizeof(*payload), MSG_TRUNC) != sizeof(*payload))
continue;
if (memcmp(payload->id, payload_id, sizeof(payload->id)) != 0)
continue;
if (payload->test_num != test_num)
continue;
// got it!
return;
}
}
static void
test_latency(unsigned latency)
{
++test_num;
// launch program with given latency
launch_latency("%u 100M", latency);
create_udp_pair(udp_socks);
// send some payload and wait
int i;
unsigned count = 0, total_delay = 0;
for (i = 0; i < 4; ++i) {
uint64_t time = get_time_us();
test_payload payload;
memcpy(payload.id, payload_id, sizeof(payload.id));
payload.test_num = test_num;
payload.time = time + latency * 1000;
send(udp_socks[i&1], &payload, sizeof(payload), MSG_NOSIGNAL);
wait_reply(udp_socks[1 - (i&1)], &payload);
// check the time is more or less what we expect
time = get_time_us();
assert(time > payload.time);
if (time - payload.time > 4000) {
fprintf(stderr, "Expected time %" PRIu64 " current %" PRIu64 " elapsed %" PRIu64"\n",
payload.time, time, time - payload.time);
exit(1);
}
++count;
total_delay += (unsigned) (time - payload.time);
}
if (total_delay / count > 1500) {
fprintf(stderr, "Average delay %u > 1500\n", total_delay / count);
exit(1);
}
close_udp_pair(udp_socks);
kill_latency();
}
int main(void)
{
printf("Testing delay introduced is correct\n");
test_latency(10);
test_latency(100);
test_latency(200);
test_latency(280);
return 0;
}
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