Use thread-safe functions where possible.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@36418 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

diff --git a/docs/latex/wx/datetime.tex b/docs/latex/wx/datetime.tex
index a97e2238f7d52c8df6e3773b7f58e945629f3201..8d85f76d820f45f7e4008f352210c024070ce30b 100644 (file)
--- a/docs/latex/wx/datetime.tex
+++ b/docs/latex/wx/datetime.tex
@@ -547,10 +547,21 @@ Returns the current time.
 
 \membersection{wxDateTime::GetTmNow}\label{wxdatetimegettmnow}
 
-\func{static struct tm *}{GetTmNow}{\void}
+\func{static struct tm *}{GetTmNow}{\param{struct tm *}{tm}}
+
+Returns the current time broken down, uses the buffer whose adress is
+passed to the function via {\it tm} to store the result.
 
-Returns the current time broken down.
+\membersection{wxDateTime::GetTmNow}
+
+\func{static struct tm *}{GetTmNow}{\void}
 
+Returns the current time broken down. Note that this function returns a
+pointer to a static buffer that's reused by calls to this function and
+certain C library functions (e.g. localtime). If there is any chance your
+code might be used in a multi-threaded application, you really should use
+the flavour of function \helpref{wxDateTime::GetTmNow}{wxdatetimegettmnow}
+taking a parameter.
 
 \membersection{wxDateTime::GetWeekDayName}\label{wxdatetimegetweekdayname}
 

diff --git a/include/wx/datetime.h b/include/wx/datetime.h
index 902ee247bf5540eacf247d416c41a591ffe18e63..53da88e61d0a74ed58d70513f852cdebb8f24bd5 100644 (file)
--- a/include/wx/datetime.h
+++ b/include/wx/datetime.h
@@ -52,6 +52,21 @@ class WXDLLIMPEXP_BASE wxDateSpan;
  *   5. wxDateTimeHolidayAuthority for Easter and other christian feasts
  */
 
+/* Two wrapper functions for thread safety */
+#ifdef HAVE_LOCALTIME_R
+#define wxLocaltime_r localtime_r
+#else
+struct tm *wxLocaltime_r(const time_t*, struct tm*)
+#warning using pseudo thread-safe wrapper for localtime to emulate localtime_r
+#endif
+
+#ifdef HAVE_GMTIME_R
+#define wxGmtime_r gmtime_r
+#else
+struct tm *wxGmtime_r(const time_t*, struct tm*)
+#warning using pseudo thread-safe wrapper for gmtime to emulate gmtime_r
+#endif
+
 /*
   The three (main) classes declared in this header represent:
 
@@ -1055,6 +1070,9 @@ public:
         return localtime(&t);
     }
 
+    // get current time using thread-safe function
+    static struct tm *GetTmNow(struct tm *tmstruct);
+
 private:
     // the current country - as it's the same for all program objects (unless
     // it runs on a _really_ big cluster system :-), this is a static member:
@@ -1537,7 +1555,8 @@ inline bool wxDateTime::IsInStdRange() const
 /* static */
 inline wxDateTime wxDateTime::Now()
 {
-    return wxDateTime(*GetTmNow());
+    struct tm tmstruct;
+    return wxDateTime(*GetTmNow(&tmstruct));
 }
 
 /* static */

diff --git a/src/common/datetime.cpp b/src/common/datetime.cpp
index 282fde1baeb6b3ef85c2df0674ec41b19747ea5c..8448eb1a5ed0281778789ad143f1d815bcfab343 100644 (file)
--- a/src/common/datetime.cpp
+++ b/src/common/datetime.cpp
@@ -307,15 +307,16 @@ static int GetTimeZone()
     static bool s_timezoneSet = false;
     static long gmtoffset = LONG_MAX; // invalid timezone
 
-    // ensure that the timezone variable is set by calling localtime
+    // ensure that the timezone variable is set by calling wxLocaltime_r
     if ( !s_timezoneSet )
     {
-        // just call localtime() instead of figuring out whether this system
-        // supports tzset(), _tzset() or something else
+        // just call wxLocaltime_r() instead of figuring out whether this
+        // system supports tzset(), _tzset() or something else
         time_t t = 0;
         struct tm *tm;
+        struct tm tmstruct;
 
-        tm = localtime(&t);
+        tm = wxLocaltime_r(&t, &tmstruct);
         s_timezoneSet = true;
 
         // note that GMT offset is the opposite of time zone and so to return
@@ -430,10 +431,11 @@ static void ReplaceDefaultYearMonthWithCurrent(int *year,
                                                wxDateTime::Month *month)
 {
     struct tm *tmNow = NULL;
+    struct tm tmstruct;
 
     if ( *year == wxDateTime::Inv_Year )
     {
-        tmNow = wxDateTime::GetTmNow();
+        tmNow = wxDateTime::GetTmNow(&tmstruct);
 
         *year = 1900 + tmNow->tm_year;
     }
@@ -441,7 +443,7 @@ static void ReplaceDefaultYearMonthWithCurrent(int *year,
     if ( *month == wxDateTime::Inv_Month )
     {
         if ( !tmNow )
-            tmNow = wxDateTime::GetTmNow();
+            tmNow = wxDateTime::GetTmNow(&tmstruct);
 
         *month = (wxDateTime::Month)tmNow->tm_mon;
     }
@@ -522,6 +524,13 @@ static wxDateTime::WeekDay GetWeekDayFromName(const wxString& name, int flags)
     return wd;
 }
 
+/* static */
+struct tm *wxDateTime::GetTmNow(struct tm *tmstruct)
+{
+    time_t t = GetTimeNow();
+    return wxLocaltime_r(&t, tmstruct);
+}
+
 // scans all digits (but no more than len) and returns the resulting number
 static bool GetNumericToken(size_t len, const wxChar*& p, unsigned long *number)
 {
@@ -988,7 +997,8 @@ wxDateTime::Country wxDateTime::GetCountry()
     {
         // try to guess from the time zone name
         time_t t = time(NULL);
-        struct tm *tm = localtime(&t);
+        struct tm tmstruct;
+        struct tm *tm = wxLocaltime_r(&t, &tmstruct);
 
         wxString tz = CallStrftime(_T("%Z"), tm);
         if ( tz == _T("WET") || tz == _T("WEST") )
@@ -1311,9 +1321,10 @@ wxDateTime& wxDateTime::Set(wxDateTime_t hour,
                       _T("Invalid time in wxDateTime::Set()") );
 
     // get the current date from system
-    struct tm *tm = GetTmNow();
+    struct tm tmstruct;
+    struct tm *tm = GetTmNow(&tmstruct);
 
-    wxDATETIME_CHECK( tm, _T("localtime() failed") );
+    wxDATETIME_CHECK( tm, _T("wxLocaltime_r() failed") );
 
     // make a copy so it isn't clobbered by the call to mktime() below
     struct tm tm1(*tm);
@@ -1479,7 +1490,8 @@ unsigned long wxDateTime::GetAsDOS() const
 {
     unsigned long ddt;
     time_t ticks = GetTicks();
-    struct tm *tm = localtime(&ticks);
+    struct tm tmstruct;
+    struct tm *tm = wxLocaltime_r(&ticks, &tmstruct);
 
     long year = tm->tm_year;
     year -= 80;
@@ -1517,14 +1529,15 @@ wxDateTime::Tm wxDateTime::GetTm(const TimeZone& tz) const
     if ( time != (time_t)-1 )
     {
         // use C RTL functions
+        struct tm tmstruct;
         tm *tm;
         if ( tz.GetOffset() == -GetTimeZone() )
         {
             // we are working with local time
-            tm = localtime(&time);
+            tm = wxLocaltime_r(&time, &tmstruct);
 
             // should never happen
-            wxCHECK_MSG( tm, Tm(), _T("localtime() failed") );
+            wxCHECK_MSG( tm, Tm(), _T("wxLocaltime_r() failed") );
         }
         else
         {
@@ -1536,10 +1549,10 @@ wxDateTime::Tm wxDateTime::GetTm(const TimeZone& tz) const
             if ( time >= 0 )
 #endif
             {
-                tm = gmtime(&time);
+                tm = wxGmtime_r(&time, &tmstruct);
 
                 // should never happen
-                wxCHECK_MSG( tm, Tm(), _T("gmtime() failed") );
+                wxCHECK_MSG( tm, Tm(), _T("wxGmtime_r() failed") );
             }
             else
             {
@@ -2120,9 +2133,10 @@ int wxDateTime::IsDST(wxDateTime::Country country) const
     time_t timet = GetTicks();
     if ( timet != (time_t)-1 )
     {
-        tm *tm = localtime(&timet);
+        struct tm tmstruct;
+        tm *tm = wxLocaltime_r(&timet, &tmstruct);
 
-        wxCHECK_MSG( tm, -1, _T("localtime() failed") );
+        wxCHECK_MSG( tm, -1, _T("wxLocaltime_r() failed") );
 
         return tm->tm_isdst;
     }
@@ -2184,14 +2198,15 @@ wxString wxDateTime::Format(const wxChar *format, const TimeZone& tz) const
     if ( (time != (time_t)-1) && !wxStrstr(format, _T("%l")) )
     {
         // use strftime()
-        tm *tm;
+        struct tm tmstruct;
+        struct tm *tm;
         if ( tz.GetOffset() == -GetTimeZone() )
         {
             // we are working with local time
-            tm = localtime(&time);
+            tm = wxLocaltime_r(&time, &tmstruct);
 
             // should never happen
-            wxCHECK_MSG( tm, wxEmptyString, _T("localtime() failed") );
+            wxCHECK_MSG( tm, wxEmptyString, _T("wxLocaltime_r() failed") );
         }
         else
         {
@@ -2204,10 +2219,10 @@ wxString wxDateTime::Format(const wxChar *format, const TimeZone& tz) const
             if ( time >= 0 )
 #endif
             {
-                tm = gmtime(&time);
+                tm = wxGmtime_r(&time, &tmstruct);
 
                 // should never happen
-                wxCHECK_MSG( tm, wxEmptyString, _T("gmtime() failed") );
+                wxCHECK_MSG( tm, wxEmptyString, _T("wxGmtime_r() failed") );
             }
             else
             {