Implement qsrand() for Symbian OS

After checking the source code of OpenC stdlib, rand and srand are
thread safe (they use Symbian's TLS internally) so the Symbian
implementation mostly follows the Windows one (where this is also true)

Task-number: QTBUG-6372
Reviewed-by: Janne Koskinen

1 files changed, 18 insertions, 13 deletions

diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp
index 62b5409..0c94482 100644
--- a/src/corelib/global/qglobal.cpp
+++ b/src/corelib/global/qglobal.cpp
@@ -77,6 +77,7 @@
 #include <e32def.h>
 #include <e32debug.h>
 #include <f32file.h>
+#include <e32math.h>
 # include "private/qcore_symbian_p.h"
 
 _LIT(qt_S60Filter, "Series60v?.*.sis");
@@ -2493,7 +2494,7 @@ bool qputenv(const char *varName, const QByteArray& value)
 #endif
 }
 
-#if (defined(Q_OS_UNIX) || defined(Q_OS_WIN)) && !defined(QT_NO_THREAD) && !defined(Q_OS_SYMBIAN)
+#if (defined(Q_OS_UNIX) || defined(Q_OS_WIN)) && !defined(QT_NO_THREAD)
 
 #  if defined(Q_OS_INTEGRITY) && defined(__GHS_VERSION_NUMBER) && (__GHS_VERSION_NUMBER < 500)
 // older versions of INTEGRITY used a long instead of a uint for the seed.
@@ -2516,8 +2517,6 @@ Q_GLOBAL_STATIC(SeedStorage, randTLS)  // Thread Local Storage for seed value
     Sets the argument \a seed to be used to generate a new random number sequence of
     pseudo random integers to be returned by qrand().
 
-    If no seed value is provided, qrand() is automatically seeded with a value of 1.
-
     The sequence of random numbers generated is deterministic per thread. For example,
     if two threads call qsrand(1) and subsequently calls qrand(), the threads will get
     the same random number sequence.
@@ -2541,8 +2540,9 @@ void qsrand(uint seed)
         srand(seed);
     }
 #else
-    // On Windows srand() and rand() already use Thread-Local-Storage
+    // On Windows and Symbian srand() and rand() already use Thread-Local-Storage
     // to store the seed between calls
+    // this is also valid for QT_NO_THREAD
     srand(seed);
 #endif
 }
@@ -2558,7 +2558,7 @@ void qsrand(uint seed)
 */
 void qsrand()
 {
-#if (defined(Q_OS_UNIX) || defined(Q_OS_WIN)) && !defined(QT_NO_THREAD) && !defined(Q_OS_SYMBIAN)
+#if (defined(Q_OS_UNIX) || defined(Q_OS_WIN)) && !defined(QT_NO_THREAD)
     SeedStorage *seedStorage = randTLS();
     if (seedStorage) {
         SeedStorageType *pseed = seedStorage->localData();
@@ -2572,24 +2572,28 @@ void qsrand()
         *pseed = QDateTime::currentDateTime().toTime_t()
                  + quintptr(&pseed)
                  + serial.fetchAndAddRelaxed(1);
-#if defined(Q_OS_WIN)
-        // for Windows the srand function must still be called.
+#if defined(Q_OS_WIN) || defined(Q_OS_SYMBIAN)
+        // for Windows and Symbian the srand function must still be called.
         srand(*pseed);
 #endif
     }
 
-#elif defined(Q_OS_WIN)
+//QT_NO_THREAD implementations
+#else
     static unsigned int seed = 0;
 
     if (seed)
         return;
 
+#if defined(Q_OS_SYMBIAN)
+    seed = Math::Random();
+#elif defined(Q_OS_WIN)
     seed = GetTickCount();
-    srand(seed);
 #else
-    // Symbian?
-
-#endif // defined(Q_OS_UNIX) || defined(Q_OS_WIN)) && !defined(QT_NO_THREAD) && !defined(Q_OS_SYMBIAN)
+    seed = quintptr(&seed) + QDateTime::currentDateTime().toTime_t();
+#endif
+    srand(seed);
+#endif // defined(Q_OS_UNIX) || defined(Q_OS_WIN)) && !defined(QT_NO_THREAD)
 }
 
 /*!
@@ -2626,8 +2630,9 @@ int qrand()
         return rand();
     }
 #else
-    // On Windows srand() and rand() already use Thread-Local-Storage
+    // On Windows and Symbian srand() and rand() already use Thread-Local-Storage
     // to store the seed between calls
+    // this is also valid for QT_NO_THREAD
     return rand();
 #endif
 }