LadybirdBrowser/ladybird
1
1
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2024-11-13 11:42:38 +03:00
Code Issues Packages Projects Releases Wiki Activity

ntpquery: Make a few variable names more descriptive

Browse Source
This commit is contained in:
Nico Weber 2020-10-16 15:57:34 -04:00 committed by Andreas Kling
parent 6fbced6f4f
commit 019788a150
Notes: sideshowbarker 2024-07-19 01:52:58 +09:00 
Author: https://github.com/nico
Commit: https://github.com/SerenityOS/serenity/commit/019788a1505
Pull-request: https://github.com/SerenityOS/serenity/pull/3786
1 changed files with 11 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
Userland/ntpquery.cpp
View File

@ -168,9 +168,9 @@ int main(int argc, char** argv)
packet.li_vn_mode = (4 << 3) | 3; // Version 4, client connection.
// The server will copy the transmit_timestamp to origin_timestamp in the reply.
timeval t;
gettimeofday(&t, nullptr);
packet.transmit_timestamp = htobe64(ntp_timestamp_from_timeval(t));
timeval local_transmit_time;
gettimeofday(&local_transmit_time, nullptr);
packet.transmit_timestamp = htobe64(ntp_timestamp_from_timeval(local_transmit_time));
ssize_t rc;
rc = sendto(fd, &packet, sizeof(packet), 0, (const struct sockaddr*)&peer_address, sizeof(peer_address));
@ -191,7 +191,8 @@ int main(int argc, char** argv)
perror("recvmsg");
return 1;
}
gettimeofday(&t, nullptr);
timeval userspace_receive_time;
gettimeofday(&userspace_receive_time, nullptr);
if ((size_t)rc < sizeof(packet)) {
fprintf(stderr, "incomplete packet recv\n");
return 1;
@ -201,15 +202,16 @@ int main(int argc, char** argv)
ASSERT(cmsg->cmsg_level == SOL_SOCKET);
ASSERT(cmsg->cmsg_type == SCM_TIMESTAMP);
ASSERT(!CMSG_NXTHDR(&msg, cmsg));
timeval packet_t;
memcpy(&packet_t, CMSG_DATA(cmsg), sizeof(packet_t));
timeval kernel_receive_time;
memcpy(&kernel_receive_time, CMSG_DATA(cmsg), sizeof(kernel_receive_time));
NtpTimestamp origin_timestamp = be64toh(packet.origin_timestamp);
NtpTimestamp receive_timestamp = be64toh(packet.receive_timestamp);
NtpTimestamp transmit_timestamp = be64toh(packet.transmit_timestamp);
NtpTimestamp destination_timestamp = ntp_timestamp_from_timeval(packet_t);
NtpTimestamp destination_timestamp = ntp_timestamp_from_timeval(kernel_receive_time);
timersub(&t, &packet_t, &t);
timeval kernel_to_userspace_latency;
timersub(&userspace_receive_time, &kernel_receive_time, &kernel_to_userspace_latency);
if (set_time) {
// FIXME: Do all the time filtering described in 5905, or at least correct for time of flight.
@ -239,7 +241,7 @@ int main(int argc, char** argv)
// When the system isn't under load, user-space t and packet_t are identical. If a shell with `yes` is running, it can be as high as 30ms in this program,
// which gets user-space time immediately after the recvmsg() call. In programs that have an event loop reading from multiple sockets, it could be higher.
printf("Receive latency: %lld.%06d s\n", t.tv_sec, t.tv_usec);
printf("Receive latency: %lld.%06d s\n", kernel_to_userspace_latency.tv_sec, kernel_to_userspace_latency.tv_usec);
}
// Parts of the "Clock Filter" computations, https://tools.ietf.org/html/rfc5905#section-10