Thread-local locale settings, fixes #244

Include/LiveTraffic.h

@@ -42,7 +42,10 @@
 #include <cstring>
 #include <ctime>
 #include <cassert>
-#include <clocale>
+#include <locale>
+#if APL
+#include <xlocale.h>
+#endif
 
 // Windows
 #if IBM
@@ -398,6 +401,26 @@ inline struct tm *localtime_s(struct tm * result, const time_t * time)
 
 #endif
 
+#if IBM
+#define locale_t         _locale_t
+#define freelocale       _free_locale
+
+#define LC_GLOBAL_LOCALE ((locale_t)-1)
+#define LC_ALL_MASK      LC_ALL
+#define LC_COLLATE_MASK  LC_COLLATE
+#define LC_CTYPE_MASK    LC_CTYPE
+#define LC_MONETARY_MASK LC_MONETARY
+#define LC_NUMERIC_MASK  LC_NUMERIC
+#define LC_TIME_MASK     LC_TIME
+
+// Base locale is ignored and mixing of masks is not supported
+#define newlocale(mask, locale, base) _create_locale(mask, locale)
+
+/// @brief Simulation of Linux' `uselocale()` function on Windows
+/// @see https://stackoverflow.com/a/17173977
+locale_t uselocale(locale_t new_locale);
+#endif
+
 /// Simpler access to strncpy_s if dest is a char array (not a pointer!)
 #define STRCPY_S(dest,src) strncpy_s(dest,sizeof(dest),src,sizeof(dest)-1)
 #define STRCPY_ATMOST(dest,src) strncpy_s(dest,sizeof(dest),strAtMost(src,sizeof(dest)-1).c_str(),sizeof(dest)-1)
@@ -411,18 +434,27 @@ inline int strerror_s( char *buf, size_t bufsz, int errnum )
 { strerror_r(errnum, buf, bufsz); return 0; }
 #endif
 
-// MARK: Thread names
-#ifdef DEBUG
-// This might not work on older Windows version, which is why we don't publish it in release builds
-#if IBM
-#define SET_THREAD_NAME(sName) SetThreadDescription(GetCurrentThread(), L##sName)
-#elif APL
-#define SET_THREAD_NAME(sName) pthread_setname_np(sName)
-#elif LIN
-#define SET_THREAD_NAME(sName) pthread_setname_np(pthread_self(),sName)
-#endif
-#else
-#define SET_THREAD_NAME(sName)
-#endif
+// MARK: Thread and Locale
+
+/// Begin a thread and set a thread-local locale
+/// @details In the communication with servers we must use internal standards,
+///          ie. C locale, so that for example the decimal point is `.`
+///          Hence we set a thread-local locale in all threads as they deal with communication.
+///          See https://stackoverflow.com/a/17173977
+class ThreadSettings {
+protected:
+    locale_t threadLocale = locale_t(0);
+    locale_t prevLocale = locale_t(0);
+public:
+    /// @brief Defines thread's name and sets the thread's locale
+    /// @param sThreadName Thread's name, max 16 chars
+    /// @param localeMask One of the LC_*_MASK constants. If `0` then locale is not changed.
+    /// @param sLocaleName New locale to set
+    ThreadSettings (const char* sThreadName,
+                    int localeMask = 0,
+                    const char* sLocaleName = "C");
+    /// Restores and cleans up locale
+    ~ThreadSettings();
+};
 
 #endif /* LiveTraffic_h */

Src/LTADSBEx.cpp

@@ -55,12 +55,7 @@ std::string ADSBExchangeConnection::GetURL (const positionTy& pos)
     else
         snprintf(url, sizeof(url), ADSBEX_URL, pos.lat(), pos.lon(),
                  dataRefs.GetFdStdDistance_nm());
-    std::string sUrl(url);
-
-    // If the locale is not set to using a decimal point we might end up with a comma in the coordinates, which OpenSky doesn't like
-    str_correctDecimalPt(sUrl, sUrl.find("/lat/"));
-
-    return sUrl;
+    return std::string(url);
 }
 
 // update shared flight data structures with received flight data
@@ -617,8 +612,8 @@ bool ADSBExchangeConnection::TestADSBExAPIKeyResult (bool& bIsKeyValid)
 // actual test, blocks, should by called via std::async
 bool ADSBExchangeConnection::DoTestADSBExAPIKey (const std::string newKey)
 {
-    // This is a thread main function, set thread's name
-    SET_THREAD_NAME("LT_TestADSBEx");
+    // This is a communication thread's main function, set thread's name and C locale
+    ThreadSettings("LT_TestADSBEx", LC_ALL_MASK);
 
     bool bResult = false;
     char curl_errtxt[CURL_ERROR_SIZE];

Src/LTApt.cpp

@@ -2378,8 +2378,8 @@ void AsyncReadApt (positionTy ctr, double radius)
 {
     static size_t lenSceneryLnBegin = strlen(APTDAT_SCENERY_LN_BEGIN);
 
-    // This is a thread main function, set thread's name
-    SET_THREAD_NAME("LT_ReadApt");
+    // This is a thread's main function, set thread's name and C locale
+    ThreadSettings("LT_ReadApt", LC_ALL_MASK);
 
     // To avoid costly distance calculations we define a bounding box
     // just by calculating lat/lon values north/east/south/west of given pos

Src/LTChannel.cpp

@@ -694,9 +694,9 @@ void LTFlightDataStop()
 // and it runs in a loop until LTFlightDataHideAircraft stops it
 void LTFlightDataSelectAc ()
 {
-    // This is a thread main function, set thread's name
-    SET_THREAD_NAME("LT_Channels");
-
+    // This is a communication thread's main function, set thread's name and C locale
+    ThreadSettings("LT_Channels", LC_ALL_MASK);
+    
     while ( !bFDMainStop )
     {
         // basis for determining when to be called next
@@ -774,6 +774,8 @@ void LTFlightDataSelectAc ()
             lk.unlock();
         }
     }
+
+    // Restore previous locale and clean up
 }
 
 // called from main thread to start showing aircraft

Src/LTFlightData.cpp

@@ -1316,8 +1316,8 @@ dequeKeyTimeTy dequeKeyPosCalc;
 // the CalcNextPos function on the respective flight data objects
 void LTFlightData::CalcNextPosMain ()
 {
-    // This is a thread main function, set thread's name
-    SET_THREAD_NAME("LT_CalcPos");
+    // This is a thread's main function, set thread's name and C locale
+    ThreadSettings("LT_CalcPos", LC_ALL_MASK);
 
     // loop till said to stop
     while ( !bFDMainStop ) {

Src/LTForeFlight.cpp

@@ -110,8 +110,8 @@ bool ForeFlightSender::StopConnection ()
 // thread main function
 void ForeFlightSender::udpSend()
 {
-    // This is a thread main function, set thread's name
-    SET_THREAD_NAME("LT_ForeFlight");
+    // This is a communication thread's main function, set thread's name and C locale
+    ThreadSettings("LT_ForeFlight", LC_ALL_MASK);
 
     //
     // *** open the UDP socket ***

Src/LTMain.cpp

@@ -329,7 +329,7 @@ bool str_correctDecimalPt (std::string& str, size_t start_pos)
     // If the locale is not set to using a decimal point we might end up with a comma in the coordinates, which OpenSky doesn't like
     // Setting the locale is no option due to immediate impact on all threads,
     // so we retrospectively replace the wrong delimiter
-    const std::lconv* pL = localeconv();
+    const lconv* pL = localeconv();
     if (pL && pL->decimal_point && std::strcmp(pL->decimal_point, "."))
     {
         str_replaceAll(str, pL->decimal_point, ".", start_pos);
@@ -680,6 +680,78 @@ bool dequal ( const double d1, const double d2 )
     ((d1 + epsilon) > d2);
 }
 
+//
+// MARK: Thread Handling
+//
+
+#if IBM
+// Simulation of Linux' `uselocale()` function on Windows
+locale_t uselocale(locale_t new_locale)
+{
+    // Retrieve the current per thread locale setting
+    bool bIsPerThread = (_configthreadlocale(0) == _ENABLE_PER_THREAD_LOCALE);
+
+    // Retrieve the current thread-specific locale
+    locale_t old_locale = bIsPerThread ? _get_current_locale() : LC_GLOBAL_LOCALE;
+
+    if(new_locale == LC_GLOBAL_LOCALE)
+    {
+        // Restore the global locale
+        _configthreadlocale(_DISABLE_PER_THREAD_LOCALE);
+    }
+    else if(new_locale != NULL)
+    {
+        // Configure the thread to set the locale only for this thread
+        _configthreadlocale(_ENABLE_PER_THREAD_LOCALE);
+
+        // Set all locale categories
+        for(int i = LC_MIN; i <= LC_MAX; i++)
+            setlocale(i, new_locale->locinfo->lc_category[i].locale);
+    }
+
+    return old_locale;
+}
+#endif
+
+// Defines thread's name and sets the thread's locale
+ThreadSettings::ThreadSettings ([[maybe_unused]] const char* sThreadName,
+                                int localeMask,
+                                const char* sLocaleName)
+{
+    // --- Set thread's name ---
+#if IBM
+    // This might not work on older Windows version, which is why we don't publish it in release builds
+#ifdef DEBUG
+    wchar_t swThreadName[100];
+    std::mbstowcs(swThreadName, sThreadName, sizeof(swThreadName));
+    SetThreadDescription(GetCurrentThread(), swThreadName);
+#endif
+
+#elif APL
+    pthread_setname_np(sThreadName);
+#elif LIN
+    pthread_setname_np(pthread_self(),sThreadName);
+#endif
+
+    // --- Set thread's locale ---
+    if (localeMask && sLocaleName)
+    {
+        threadLocale = newlocale(localeMask, sLocaleName, NULL);
+        prevLocale = uselocale(threadLocale);
+    }
+}
+
+// Restores and cleans up locale
+ThreadSettings::~ThreadSettings()
+{
+    if (prevLocale)
+        uselocale(prevLocale);
+    if (threadLocale) {
+        freelocale(threadLocale);
+        threadLocale = locale_t(0);
+    }
+}
+
 //
 //MARK: Callbacks
 //

Src/LTOpenGlider.cpp

@@ -151,10 +151,7 @@ std::string OpenGliderConnection::GetURL (const positionTy& pos)
                  box.se.lat(),              // lamin
                  box.se.lon(),              // lomax
                  box.nw.lon());             // lomin
-        std::string sUrl(url);
-        // If the locale is not set to using a decimal point we might end up with a comma in the coordinates, which OpenSky doesn't like
-        str_correctDecimalPt(sUrl, sUrl.find('?'));
-        return sUrl;
+        return std::string(url);
     } else {
         // otherwise (and by default) we are to use the direct APRS connection
         APRSStartUpdate(pos, (unsigned)dataRefs.GetFdStdDistance_km());
@@ -335,9 +332,9 @@ std::string OpenGliderConnection::GetStatusText () const
 // Main function for APRS connection, expected to be started in a thread
 void OpenGliderConnection::APRSMain (const positionTy& pos, unsigned dist_km)
 {
-    // This is a thread main function, set thread's name
-    SET_THREAD_NAME("LT_OGN_APRS");
-    
+    // This is a communication thread's main function, set thread's name and C locale
+    ThreadSettings("LT_OGN_APRS", LC_ALL_MASK);
+
     try {
         // open a TCP connection to APRS.glidernet.org
         aprsLastData = NAN;
@@ -904,9 +901,9 @@ static size_t OGNAcListNetwCB(char *ptr, size_t, size_t nmemb, void* userdata)
 /// @see http://ddb.glidernet.org/download/
 static bool OGNAcListDoDownload ()
 {
-    // This is a thread main function, set thread's name
-    SET_THREAD_NAME("LT_OGNAcList");
-    
+    // This is a communication thread's main function, set thread's name and C locale
+    ThreadSettings("LT_OGNAcList", LC_ALL_MASK);
+
     bool bRet = false;
     try {
         char curl_errtxt[CURL_ERROR_SIZE];

Src/LTOpenSky.cpp

@@ -125,12 +125,7 @@ std::string OpenSkyConnection::GetURL (const positionTy& pos)
              box.nw.lon(),              // lomin
              box.nw.lat(),              // lamax
              box.se.lon() );            // lomax
-    std::string sUrl(url);
-
-    // If the locale is not set to using a decimal point we might end up with a comma in the coordinates, which OpenSky doesn't like
-    str_correctDecimalPt(sUrl, sUrl.find('?'));
-
-    return sUrl;
+    return std::string(url);
 }
 
 // update shared flight data structures with received flight data

Src/LTRealTraffic.cpp

@@ -352,8 +352,8 @@ bool RealTrafficConnection::StopConnections()
 
 void RealTrafficConnection::tcpConnection ()
 {
-    // This is a thread main function, set thread's name
-    SET_THREAD_NAME("LT_RT_TCP");
+    // This is a communication thread's main function, set thread's name and C locale
+    ThreadSettings("LT_RT_TCP", LC_ALL_MASK);
 
     // sanity check: return in case of wrong status
     if (!IsConnecting()) {
@@ -471,8 +471,8 @@ void RealTrafficConnection::SendUsersPlanePos()
 // forwards that to the flight data
 void RealTrafficConnection::udpListen ()
 {
-    // This is a thread main function, set thread's name
-    SET_THREAD_NAME("LT_RT_UDP");
+    // This is a communication thread's main function, set thread's name and C locale
+    ThreadSettings("LT_RT_UDP", LC_ALL_MASK);
 
     // sanity check: return in case of wrong status
     if (!IsConnecting()) {

Src/LTVersion.cpp

@@ -183,8 +183,8 @@ size_t FetchVersionCB(char *ptr, size_t, size_t nmemb, void* userdata)
 // This function would block. Idea is to call it in a thread like with std::async
 bool FetchXPlaneOrgVersion ()
 {
-    // This is a thread main function, set thread's name
-    SET_THREAD_NAME("LT_Version");
+    // This is a communication thread's main function, set thread's name and C locale
+    ThreadSettings("LT_Version", LC_ALL_MASK);
 
     char curl_errtxt[CURL_ERROR_SIZE];
     std::string readBuf;

Src/LTWeather.cpp

@@ -187,9 +187,9 @@ size_t WeatherFetchCB(char *ptr, size_t, size_t nmemb, void* userdata)
 // This function would block. Idea is to call it in a thread like with std::async
 bool WeatherFetch (float _lat, float _lon, float _radius_nm)
 {
-    // This is a thread main function, set thread's name
-    SET_THREAD_NAME("LT_Weather");
-    
+    // This is a communication thread's main function, set thread's name and C locale
+    ThreadSettings("LT_Weather", LC_ALL_MASK);
+
     bool bRet = false;
     try {
         char curl_errtxt[CURL_ERROR_SIZE];

docs/readme.html

@@ -148,6 +148,11 @@ <h3>v3.1.2</h3>
             refresh rate above a configured height AGL works no matter
             which "Live Data Refresh" is configured.
         </li>
+        <li>
+            Fixed <a href="https://github.com/TwinFan/LiveTraffic/issues/244">#244</a>,
+            making all network communications resistent to locales
+            specifying a non-dot decimal point, an issue that surfaced with XP12 only.
+        </li>
     </ul>
 
     <h3>v3.1.1</h3>