Change almost all other uses of qrand() to QRandomGenerator

The vast majority is actually switched to QRandomGenerator::bounded(),
which gives a mostly uniform distribution over the [0, bound)
range. There are very few floating point cases left, as many of those
that did use floating point did not need to, after all. (I did leave
some that were too ugly for me to understand)

This commit also found a couple of calls to rand() instead of qrand().

This commit does not include changes to SSL code that continues to use
qrand() (job for someone else):
  src/network/ssl/qsslkey_qt.cpp
  src/network/ssl/qsslsocket_mac.cpp
  tests/auto/network/ssl/qsslsocket/tst_qsslsocket.cpp

Change-Id: Icd0e0d4b27cb4e5eb892fffd14b5285d43f4afbf
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

7 files changed, 14 insertions, 17 deletions

diff --git a/tests/auto/corelib/io/largefile/tst_largefile.cpp b/tests/auto/corelib/io/largefile/tst_largefile.cpp
index 5975303ca6..2d13e6166d 100644
--- a/tests/auto/corelib/io/largefile/tst_largefile.cpp
+++ b/tests/auto/corelib/io/largefile/tst_largefile.cpp
@@ -31,6 +31,7 @@
 #include <QtAlgorithms>
 #include <QFile>
 #include <QFileInfo>
+#include <QRandomGenerator>
 #include <qplatformdefs.h>
 
 #include <QDebug>
@@ -174,8 +175,7 @@ static inline QByteArray generateDataBlock(int blockSize, QString text, qint64 u
 
     static qint64 counter = 0;
 
-    qint64 randomBits = ((qint64)qrand() << 32)
-            | ((qint64)qrand() & 0x00000000ffffffff);
+    qint64 randomBits = QRandomGenerator::global()->generate64();
 
     appendRaw(block, randomBits);
     appendRaw(block, userBits);
diff --git a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
index 3a52c684d0..5ecdd92228 100644
--- a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
+++ b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
@@ -2362,8 +2362,8 @@ void tst_QObject::testUserData()
 
     // Randomize the table a bit
     for (int i=0; i<100; ++i) {
-        int p1 = rand() % USER_DATA_COUNT;
-        int p2 = rand() % USER_DATA_COUNT;
+        int p1 = QRandomGenerator::global()->bounded(USER_DATA_COUNT);
+        int p2 = QRandomGenerator::global()->bounded(USER_DATA_COUNT);
 
         int tmp = user_data_ids[p1];
         user_data_ids[p1] = user_data_ids[p2];
diff --git a/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp b/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
index 8a46bc1c55..8883b6360f 100644
--- a/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
+++ b/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
@@ -115,7 +115,6 @@ Q_CONSTRUCTOR_FUNCTION(initializeLang)
 
 static QString seedAndTemplate()
 {
-    qsrand(QDateTime::currentSecsSinceEpoch());
     return QDir::tempPath() + "/tst_qmimedatabase-XXXXXX";
 }
 
diff --git a/tests/auto/corelib/plugin/quuid/testProcessUniqueness/main.cpp b/tests/auto/corelib/plugin/quuid/testProcessUniqueness/main.cpp
index daf9b1579a..d1e138d8eb 100644
--- a/tests/auto/corelib/plugin/quuid/testProcessUniqueness/main.cpp
+++ b/tests/auto/corelib/plugin/quuid/testProcessUniqueness/main.cpp
@@ -35,9 +35,6 @@ int main(int argc, char **argv)
     Q_UNUSED(argc)
     Q_UNUSED(argv)
 
-    // First, break QUuid.
-    qrand();
-
     // Now print a few uuids.
     printf("%s", qPrintable(QUuid::createUuid().toString()));
     printf("%s", qPrintable(QUuid::createUuid().toString()));
diff --git a/tests/auto/corelib/thread/qfuture/tst_qfuture.cpp b/tests/auto/corelib/thread/qfuture/tst_qfuture.cpp
index 37b052bf1d..58bebe19ac 100644
--- a/tests/auto/corelib/thread/qfuture/tst_qfuture.cpp
+++ b/tests/auto/corelib/thread/qfuture/tst_qfuture.cpp
@@ -36,6 +36,7 @@
 #include <qresultstore.h>
 #include <qthreadpool.h>
 #include <qexception.h>
+#include <qrandom.h>
 #include <private/qfutureinterface_p.h>
 
 // COM interface macro.
@@ -1456,7 +1457,7 @@ void tst_QFuture::nonGlobalThreadPool()
 
         void run() Q_DECL_OVERRIDE
         {
-            const int ms = 100 + (qrand() % 100 - 100/2);
+            const int ms = 100 + (QRandomGenerator::global()->bounded(100) - 100/2);
             QThread::msleep(ms);
             reportResult(Answer);
             reportFinished();
diff --git a/tests/auto/corelib/tools/qalgorithms/tst_qalgorithms.cpp b/tests/auto/corelib/tools/qalgorithms/tst_qalgorithms.cpp
index e13c2894af..72299402f0 100644
--- a/tests/auto/corelib/tools/qalgorithms/tst_qalgorithms.cpp
+++ b/tests/auto/corelib/tools/qalgorithms/tst_qalgorithms.cpp
@@ -37,6 +37,7 @@
 #include <qalgorithms.h>
 #include <QStringList>
 #include <QString>
+#include <QRandomGenerator>
 #include <QVector>
 
 #define Q_TEST_PERFORMANCE 0
@@ -133,7 +134,7 @@ QVector<DataType> generateData(QString dataSetType, const int length)
     QVector<DataType> container;
     if (dataSetType == "Random") {
         for (int i = 0; i < length; ++i)
-            container.append(rand());
+            container.append(QRandomGenerator::global()->generate());
     } else if (dataSetType == "Ascending") {
         for (int i = 0; i < length; ++i)
             container.append(i);
@@ -1082,12 +1083,12 @@ void tst_QAlgorithms::popCount_data_impl(size_t sizeof_T_Int)
     // and some random ones:
     if (sizeof_T_Int >= 8)
         for (size_t i = 0; i < 1000; ++i) {
-            const quint64 input = quint64(qrand()) << 32 | quint32(qrand());
+            const quint64 input = QRandomGenerator::global()->generate64();
             QTest::addRow("0x%016llx", input) << input << bitsSetInInt64(input);
         }
         else if (sizeof_T_Int >= 2)
             for (size_t i = 0; i < 1000 ; ++i) {
-                const quint32 input = qrand();
+                const quint32 input = QRandomGenerator::global()->generate();
                 if (sizeof_T_Int >= 4)
                     QTest::addRow("0x%08x", input) << quint64(input) << bitsSetInInt(input);
                 else
@@ -1129,7 +1130,7 @@ void tst_QAlgorithms::countTrailing_data_impl(size_t sizeof_T_Int)
     // and some random ones:
     for (uint i = 0; i < sizeof_T_Int*8; ++i) {
         for (uint j = 0; j < sizeof_T_Int*3; ++j) {  // 3 is arbitrary
-            const quint64 r = quint64(qrand()) << 32 | quint32(qrand());
+            const quint64 r = QRandomGenerator::global()->generate64();
             const quint64 b = Q_UINT64_C(1) << i;
             const quint64 mask = ((~(b-1)) ^ b) & type_mask;
             const quint64 input = (r&mask) | b;
@@ -1166,7 +1167,7 @@ void tst_QAlgorithms::countLeading_data_impl(size_t sizeof_T_Int)
     // and some random ones:
     for (uint i = 0; i < sizeof_T_Int*8; ++i) {
         for (uint j = 0; j < sizeof_T_Int*3; ++j) {  // 3 is arbitrary
-            const quint64 r = quint64(qrand()) << 32 | quint32(qrand());
+            const quint64 r = QRandomGenerator::global()->generate64();
             const quint64 b = Q_UINT64_C(1) << i;
             const quint64 mask = b-1;
             const quint64 input = (r&mask) | b;
diff --git a/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp b/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
index 442d4d089c..e1dcdb8407 100644
--- a/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
+++ b/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
@@ -1884,7 +1884,7 @@ class StrongThread: public QThread
 protected:
     void run()
     {
-        usleep(rand() % 2000);
+        usleep(QRandomGenerator::global()->bounded(2000));
         ptr->ref();
         ptr.clear();
     }
@@ -1897,7 +1897,7 @@ class WeakThread: public QThread
 protected:
     void run()
     {
-        usleep(rand() % 2000);
+        usleep(QRandomGenerator::global()->bounded(2000));
         QSharedPointer<ThreadData> ptr = weak;
         if (ptr)
             ptr->ref();
@@ -1959,7 +1959,6 @@ void tst_QSharedPointer::threadStressTest()
 
         base.clear();
 
-        srand(time(NULL));
         // start threads
         for (int i = 0; i < allThreads.count(); ++i)
             if (allThreads[i]) allThreads[i]->start();