diff options
author | Nico Weber <thakis@chromium.org> | 2020-10-16 15:57:34 -0400 |
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committer | Andreas Kling <kling@serenityos.org> | 2020-10-17 23:19:14 +0200 |
commit | 019788a1505430be54843f54926e581d1e6efd8b (patch) | |
tree | 433dbcc33c9076d5987c62fa5be1379749200b3b /Userland/ntpquery.cpp | |
parent | 6fbced6f4f690f60385edb2bd28e62fc08019606 (diff) | |
download | serenity-019788a1505430be54843f54926e581d1e6efd8b.zip |
ntpquery: Make a few variable names more descriptive
Diffstat (limited to 'Userland/ntpquery.cpp')
-rw-r--r-- | Userland/ntpquery.cpp | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/Userland/ntpquery.cpp b/Userland/ntpquery.cpp index 4ee6e9250e..2836676089 100644 --- a/Userland/ntpquery.cpp +++ b/Userland/ntpquery.cpp @@ -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 |