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-rw-r--r--src/ClockTAI.cpp306
-rw-r--r--src/ClockTAI.h36
-rw-r--r--src/DabMultiplexer.cpp4
3 files changed, 272 insertions, 74 deletions
diff --git a/src/ClockTAI.cpp b/src/ClockTAI.cpp
index 5e89d9f..e38eca1 100644
--- a/src/ClockTAI.cpp
+++ b/src/ClockTAI.cpp
@@ -3,7 +3,7 @@
2011, 2012 Her Majesty the Queen in Right of Canada (Communications
Research Center Canada)
- Copyright (C) 2016
+ Copyright (C) 2017
Matthias P. Braendli, matthias.braendli@mpb.li
http://www.opendigitalradio.org
@@ -25,11 +25,13 @@
along with ODR-DabMux. If not, see <http://www.gnu.org/licenses/>.
*/
-/* This file downloads the TAI-UTC bulletin from the USNO servers, parses
- * it so that correct time can be communicated in EDI timestamps.
+/* This file downloads the TAI-UTC bulletins from the USNO servers and/or
+ * from IETF and parses them so that correct time can be communicated in EDI
+ * timestamps.
*
* This file contains self-test code that can be executed by running
- * g++ -g -Wall -DTEST -DHAVE_CURL -std=c++11 -lcurl -lboost_regex ClockTAI.cpp Log.cpp -o taitest && ./taitest
+ * g++ -g -Wall -DTEST -DHAVE_CURL -std=c++11 -lcurl -lboost_regex -pthread \
+ * ClockTAI.cpp Log.cpp -o taitest && ./taitest
*/
#ifdef HAVE_CONFIG_H
@@ -54,39 +56,169 @@
#include <algorithm>
#include <boost/regex.hpp>
-/* Last two lines from bulletin, example:
+#ifdef TEST
+static bool wait_longer = true;
+#endif
+
+// leap seconds insertion bulletin is available at
+static const char* tai_ietf_url =
+ "http://www.ietf.org/timezones/data/leap-seconds.list";
+// and in the tz distribution
+static const char* tai_tz_url =
+ "https://raw.githubusercontent.com/eggert/tz/master/leap-seconds.list";
+// leap-seconds.list has a different format from the USNO one
+
+static const char* tai_usno_url1 =
+ "http://maia.usno.navy.mil/ser7/tai-utc.dat";
+static const char* tai_usno_url2 =
+ "http://toshi.nofs.navy.mil/ser7/tai-utc.dat";
+/* Last two lines from USNO bulletin, example:
2015 JUL 1 =JD 2457204.5 TAI-UTC= 36.0 S + (MJD - 41317.) X 0.0 S
2017 JAN 1 =JD 2457754.5 TAI-UTC= 37.0 S + (MJD - 41317.) X 0.0
*/
-ClockTAI::ClockTAI()
+int ClockTAI::download_offset_task()
{
- m_offset = 0;
+ int offset = 0;
+ bool offset_valid = false;
+
+ // Clear the bulletin
+ std::stringstream new_bulletin;
+ m_bulletin.swap(new_bulletin);
+
+ try {
+ download_tai_utc_bulletin(tai_ietf_url);
+ offset = parse_ietf_bulletin();
+ offset_valid = true;
+ }
+ catch (std::runtime_error& e)
+ {
+ etiLog.level(warn) <<
+ "TAI-UTC offset from IETF could not be retrieved: " <<
+ e.what();
+ }
+
+ if (not offset_valid) {
+ try {
+ download_tai_utc_bulletin(tai_tz_url);
+ offset = parse_ietf_bulletin();
+ offset_valid = true;
+ }
+ catch (std::runtime_error& e)
+ {
+ etiLog.level(warn) <<
+ "TAI-UTC offset from TZ distribution could not be retrieved: " <<
+ e.what();
+ }
+ }
+
+ if (not offset_valid) {
+ try {
+ download_tai_utc_bulletin(tai_usno_url1);
+ offset = parse_usno_bulletin();
+ offset_valid = true;
+ }
+ catch (std::runtime_error& e)
+ {
+ etiLog.level(warn) <<
+ "TAI-UTC offset from USNO server #1 could not be retrieved: " <<
+ e.what();
+ }
+ }
+
+ if (not offset_valid) {
+ try {
+ download_tai_utc_bulletin(tai_usno_url2);
+ offset = parse_usno_bulletin();
+ offset_valid = true;
+ }
+ catch (std::runtime_error& e)
+ {
+ etiLog.level(warn) <<
+ "TAI-UTC offset from USNO server #2 could not be retrieved: " <<
+ e.what();
+ }
+ }
+
+ if (offset_valid) {
+ // With the current evolution of the offset, we're probably going
+ // to reach 500 long after DAB gets replaced by another standard.
+ if (offset < 0 or offset > 500) {
+ std::stringstream ss;
+ ss << "TAI offset " << offset << " out of range";
+ throw std::range_error(ss.str());
+ }
+
+ return offset;
+ }
+ else {
+ // Try again in 1 hour
+ m_bulletin_download_time += std::chrono::hours(1);
+
+ throw std::runtime_error("Could not fetch TAI-UTC offset");
+ }
}
+
int ClockTAI::get_offset()
{
auto time_now = std::chrono::system_clock::now();
+ if (not m_offset_valid) {
+#ifdef TEST
+ m_offset = 37; // Valid in early 2017
+ m_offset_valid = true;
+
+ // Simulate requiring a new download
+ m_bulletin_download_time = std::chrono::system_clock::now() -
+ std::chrono::hours(24 * 40);
+#else
+ // First time we run we must block until we know
+ // the offset
+ m_offset = download_offset_task();
+ m_offset_valid = true;
+ m_bulletin_download_time = std::chrono::system_clock::now();
+#endif
+ etiLog.level(info) <<
+ "Initialised TAI-UTC offset to " << m_offset << "s.";
+ }
+
if (time_now - m_bulletin_download_time >
std::chrono::seconds(3600 * 24 * 31)) {
// Refresh if it's older than one month. Leap seconds are
// announced several months in advance
- if (download_tai_utc_bulletin(tai_data_url1) == 0) {
- m_offset = parse_tai_offset();
- }
- else if (download_tai_utc_bulletin(tai_data_url2) == 0) {
- m_offset = parse_tai_offset();
+ if (m_offset_future.valid()) {
+ auto state = m_offset_future.wait_for(std::chrono::seconds(0));
+ switch (state) {
+ case std::future_status::ready:
+ m_offset = m_offset_future.get();
+ m_offset_valid = true;
+ m_bulletin_download_time = std::chrono::system_clock::now();
+
+ etiLog.level(info) <<
+ "Updated TAI-UTC offset to " << m_offset << "s.";
+#ifdef TEST
+ wait_longer = false;
+#endif
+ break;
+
+ case std::future_status::deferred:
+ case std::future_status::timeout:
+ // Not ready yet
+#ifdef TEST
+ etiLog.level(debug) << " async not ready yet";
+#endif
+ break;
+ }
}
else {
- // Try again in 1 hour
- m_bulletin_download_time += std::chrono::hours(1);
-
- throw std::runtime_error("Could not fetch TAI-UTC offset");
+#ifdef TEST
+ etiLog.level(debug) << " Launch async";
+#endif
+ m_offset_future = std::async(std::launch::async,
+ &ClockTAI::download_offset_task, this);
}
-
- etiLog.level(info) << "Updated TAI-UTC offset to " << m_offset << "s.";
}
return m_offset;
@@ -110,15 +242,88 @@ int ClockTAI::update_local_tai_clock(int offset)
}
#endif
-int ClockTAI::parse_tai_offset()
+int ClockTAI::parse_ietf_bulletin()
+{
+ // Example Line:
+ // 3692217600 37 # 1 Jan 2017
+ //
+ // NTP timestamp <TAB> leap seconds <TAB> # some comment
+ // The NTP timestamp starts at epoch 1.1.1900.
+ // The difference between NTP timestamps and unix epoch is 70
+ // years i.e. 2208988800 seconds
+
+ const int64_t ntp_unix_offset = 2208988800L;
+
+ boost::regex regex_bulletin(R"(([0-9]+)\s+([0-9]+)\s+#.*)");
+
+ time_t now = time(nullptr);
+
+ int tai_utc_offset = 0;
+
+ int tai_utc_offset_valid = false;
+
+ /* We cannot just take the last line, because it might
+ * be in the future, announcing an upcoming leap second.
+ *
+ * So we need to look at the current date, and compare it
+ * with the date of the leap second.
+ */
+ for (std::string line; std::getline(m_bulletin, line); ) {
+
+ boost::smatch bulletin_entry;
+
+ bool is_match = boost::regex_search(line, bulletin_entry, regex_bulletin);
+ if (is_match) {
+ if (bulletin_entry.size() != 3) {
+ throw std::runtime_error(
+ "Incorrect number of matched TAI IETF bulletin entries");
+ }
+ const std::string bulletin_ntp_timestamp(bulletin_entry[1]);
+ const std::string bulletin_offset(bulletin_entry[2]);
+
+ const int64_t timestamp_unix =
+ std::atol(bulletin_ntp_timestamp.c_str()) - ntp_unix_offset;
+
+ const int offset = std::atoi(bulletin_offset.c_str());
+#if TEST
+ std::cerr << "Match for line " << line << std::endl;
+ std::cerr << " " << timestamp_unix << " < " << now << std::endl;
+#endif
+ // Ignore entries announcing leap seconds in the future
+ if (timestamp_unix < now) {
+ tai_utc_offset = offset;
+ tai_utc_offset_valid = true;
+ }
+#if TEST
+ else {
+ std::cerr << "IETF Ignoring offset " << bulletin_offset <<
+ " at TS " << bulletin_ntp_timestamp <<
+ " in the future" << std::endl;
+ }
+#endif
+ }
+ }
+
+ if (not tai_utc_offset_valid) {
+ throw std::runtime_error("No data in TAI bulletin");
+ }
+
+ return tai_utc_offset;
+}
+
+int ClockTAI::parse_usno_bulletin()
{
- boost::regex regex_bulletin("([0-9]{4}) ([A-Z]{3}) +([0-9]+) =JD +[0-9.]+ +TAI-UTC= *([0-9.]+)");
- /* regex groups: Year Month Day Julian date Offset */
+ boost::regex regex_bulletin(
+ "([0-9]{4}) ([A-Z]{3}) +([0-9]+) =JD +[0-9.]+ +TAI-UTC= *([0-9.]+)");
+ /* regex groups:
+ * Year Month Day Julian date Offset
+ */
const std::array<std::string, 12> months{"JAN", "FEB", "MAR", "APR", "MAY", "JUN", "JUL", "AUG", "SEP", "OCT", "NOV", "DEC"};
- /* I'm not certain about the format they would use if the day is a two-digit number. Will they keep
- * two spaces after the month? The regex should be resilient enough in that case.
+ /* I'm not certain about the format they would use if the day is a
+ * two-digit number. Will they keep two spaces after the month? The regex
+ * should be resilient enough in that case.
*/
time_t now = time(nullptr);
@@ -133,8 +338,7 @@ int ClockTAI::parse_tai_offset()
int tai_utc_offset = 0;
-
- int linecount = 0;
+ bool tai_utc_offset_valid = false;
/* We cannot just take the last line, because it might
* be in the future, announcing an upcoming leap second.
@@ -143,7 +347,6 @@ int ClockTAI::parse_tai_offset()
* with the date of the leap second.
*/
for (std::string line; std::getline(m_bulletin, line); ) {
- linecount++;
boost::smatch bulletin_entry;
@@ -151,7 +354,8 @@ int ClockTAI::parse_tai_offset()
if (is_match) {
if (bulletin_entry.size() != 5) {
- throw std::runtime_error("Incorrect number of matched TAI bulletin entries");
+ throw std::runtime_error(
+ "Incorrect number of matched USNO TAI bulletin entries");
}
const std::string bulletin_year(bulletin_entry[1]);
const std::string bulletin_month_name(bulletin_entry[2]);
@@ -174,6 +378,7 @@ int ClockTAI::parse_tai_offset()
std::distance(months.begin(), match) == month and
std::atoi(bulletin_day.c_str()) < day) ) {
tai_utc_offset = std::atoi(bulletin_offset.c_str());
+ tai_utc_offset_valid = true;
}
#if TEST
else {
@@ -190,18 +395,10 @@ int ClockTAI::parse_tai_offset()
#endif
}
- if (linecount == 0) {
+ if (not tai_utc_offset_valid) {
throw std::runtime_error("No data in TAI bulletin");
}
- // With the current evolution of the offset, we're probably going
- // to reach 500 long after DAB gets replaced by another standard.
- if (tai_utc_offset < 0 or tai_utc_offset > 500) {
- std::stringstream ss;
- ss << "TAI offset " << tai_utc_offset << " out of range";
- throw std::range_error(ss.str());
- }
-
return tai_utc_offset;
}
@@ -220,10 +417,8 @@ size_t ClockTAI::fill_bulletin_cb(
return ((ClockTAI*)ctx)->fill_bulletin(ptr, size, nmemb);
}
-int ClockTAI::download_tai_utc_bulletin(const char* url)
+void ClockTAI::download_tai_utc_bulletin(const char* url)
{
- int r = 0;
-
#ifdef HAVE_CURL
CURL *curl;
CURLcode res;
@@ -231,30 +426,23 @@ int ClockTAI::download_tai_utc_bulletin(const char* url)
curl = curl_easy_init();
if (curl) {
curl_easy_setopt(curl, CURLOPT_URL, url);
- /* example.com is redirected, so we tell libcurl to follow redirection */
+ /* Tell libcurl to follow redirection */
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, ClockTAI::fill_bulletin_cb);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, this);
res = curl_easy_perform(curl);
- if (res != CURLE_OK) {
- fprintf(stderr, "curl_easy_perform() failed: %s\n",
- curl_easy_strerror(res));
+ /* always cleanup ! */
+ curl_easy_cleanup(curl);
- r = 1;
- }
- else {
- // Save the download time of the bulletin
- m_bulletin_download_time = std::chrono::system_clock::now();
+ if (res != CURLE_OK) {
+ throw std::runtime_error( "TAI-UTC bulletin download failed: " +
+ std::string(curl_easy_strerror(res)));
}
-
- /* always cleanup */
- curl_easy_cleanup(curl);
}
#else
throw std::runtime_error("Cannot download TAI Clock information without cURL");
#endif // HAVE_CURL
- return r;
}
#if 0
@@ -297,11 +485,15 @@ int main(int argc, char **argv)
ClockTAI tai;
- try {
- cerr << "Offset is " << tai.get_offset() << endl;
- }
- catch (std::exception &e) {
- cerr << "Exception " << e.what() << endl;
+ while (wait_longer) {
+ try {
+ cerr << "Offset is " << tai.get_offset() << endl;
+ }
+ catch (std::exception &e) {
+ cerr << "Exception " << e.what() << endl;
+ }
+
+ std::this_thread::sleep_for(std::chrono::seconds(2));
}
return 0;
diff --git a/src/ClockTAI.h b/src/ClockTAI.h
index 499fa56..6ab9ab6 100644
--- a/src/ClockTAI.h
+++ b/src/ClockTAI.h
@@ -3,7 +3,7 @@
2011, 2012 Her Majesty the Queen in Right of Canada (Communications
Research Center Canada)
- Copyright (C) 2016
+ Copyright (C) 2017
Matthias P. Braendli, matthias.braendli@mpb.li
http://www.opendigitalradio.org
@@ -26,18 +26,19 @@
*/
/* The EDI output needs TAI clock, according to ETSI TS 102 693 Annex F
- * "EDI Timestamps". This module sets the local CLOCK_TAI clock by
+ * "EDI Timestamps". This module can set the local CLOCK_TAI clock by
* setting the TAI-UTC offset using adjtimex.
*
- * This functionality requires Linux 3.10 (30 Jun 2013) or newer */
+ * This functionality requires Linux 3.10 (30 Jun 2013) or newer.
+ */
-#ifndef __CLOCK_TAI_H_
-#define __CLOCK_TAI_H_
+#pragma once
#include <stdint.h>
#include <stdlib.h>
#include <sstream>
#include <chrono>
+#include <future>
// EDI needs to know UTC-TAI, but doesn't need the CLOCK_TAI to be set.
// We can keep this code, maybe for future use
@@ -46,8 +47,6 @@
/* Loads, parses and represents TAI-UTC offset information from the USNO bulletin */
class ClockTAI {
public:
- ClockTAI();
-
// Fetch the bulletin from the USNO website and return the current
// TAI-UTC offset.
// Throws runtime_error on failure.
@@ -60,19 +59,26 @@ class ClockTAI {
#endif
private:
- // leap seconds insertion bulletin is available at
- const char* tai_data_url1 = "http://maia.usno.navy.mil/ser7/tai-utc.dat";
- const char* tai_data_url2 = "http://toshi.nofs.navy.mil/ser7/tai-utc.dat";
+ int download_offset_task(void);
+
+ // Download of new bulletin is done asynchronously
+ std::future<int> m_offset_future;
+ // The currently used TAI-UTC offset
int m_offset;
+ int m_offset_valid = false;
+
std::stringstream m_bulletin;
std::chrono::system_clock::time_point m_bulletin_download_time;
- // Load bulletin into m_bulletin, return 0 on success
- int download_tai_utc_bulletin(const char* url);
+ // Load bulletin into m_bulletin
+ void download_tai_utc_bulletin(const char* url);
- // read TAI offset from m_bulletin
- int parse_tai_offset(void);
+ // read TAI offset from m_bulletin in IETF format
+ int parse_ietf_bulletin(void);
+
+ // read TAI offset from m_bulletin in USNO format
+ int parse_usno_bulletin(void);
// callback that receives data from cURL
size_t fill_bulletin(char *ptr, size_t size, size_t nmemb);
@@ -82,5 +88,3 @@ class ClockTAI {
char *ptr, size_t size, size_t nmemb, void *ctx);
};
-#endif // __CLOCK_TAI_H_
-
diff --git a/src/DabMultiplexer.cpp b/src/DabMultiplexer.cpp
index ff35c2f..51a67e7 100644
--- a/src/DabMultiplexer.cpp
+++ b/src/DabMultiplexer.cpp
@@ -640,8 +640,10 @@ void DabMultiplexer::mux_frame(std::vector<std::shared_ptr<DabOutput> >& outputs
bool tist_enabled = m_pt.get("general.tist", false);
if (tist_enabled and edi_conf.enabled()) {
- edi_tagDETI.set_tai_utc_offset(m_clock_tai.get_offset());
edi_tagDETI.set_seconds(edi_time);
+
+ // In case get_offset fails, we still want to update the EDI seconds
+ edi_tagDETI.set_tai_utc_offset(m_clock_tai.get_offset());
}
}