QT: sqlite and qlist issue - c++

Question

I have a multithread application which accesses a DB from multiple thread, and randomically I fall in this error (not the same query)...
__GI___libc_free (mem=0x7fff00042660) at /build/glibc-vjB4T1/glibc-2.28/malloc/malloc.c:3093
QList<_RData>::node_destruct (this=0x7fffebffce08, from=0x7fffe4037fc0, to=0x7fffe4037fd8) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qlist.h:494
QList<_RData>::dealloc (this=0x7fffebffce08, data=0x7fffe4037fb0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qlist.h:865
QList<_RData>::~QList (this=0x7fffebffce08) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qlist.h:827
QList<_RData>::operator= (this=0x55555565cd68, other=#0x7fffebffd880: {<QListSpecialMethods<_RoomData>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7ffff6ff76c0 <QListData::shared_null>}, d = 0x7ffff6ff76c0 <QListData::shared_null>}}) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qlist.h:159
AMProcess::doActionAM (this=0x55555565cc30) at /smart/software/AudioIO/AMProcess.cpp:453
QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, void (AMProcess::*)()>::call(void (AMProcess::*)(), AMProcess*, void**) (f=(void (AMProcess::*)(AMProcess * const)) 0x5555555b943c <AMProcess::doActionAM()>, o=0x55555565cc30, arg=0x7fffebffee40) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:134
QtPrivate::FunctionPointer<void (AMProcess::*)()>::call<QtPrivate::List<>, void>(void (AMProcess::*)(), AMProcess*, void**) (f=(void (AMProcess::*)(AMProcess * const)) 0x5555555b943c <AMProcess::doActionAM()>, o=0x55555565cc30, arg=0x7fffebffee40) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:167
QtPrivate::QSlotObject<void (AMProcess::*)(), QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) (which=1, this_=0x555555661cf0, r=0x55555565cc30, a=0x7fffebffee40, ret=0x0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:396
QMetaObject::activate(QObject*, int, int, void**) () at null:
QThread::started(QThread::QPrivateSignal) () at null:
?? () at null:
start_thread (arg=<optimized out>) at /build/glibc-vjB4T1/glibc-2.28/nptl/pthread_create.c:486
clone () at /build/glibc-vjB4T1/glibc-2.28/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:95
This is some snippets of my code
rData = DBRManager::ReadRData("R", m_connName);
if (rData.size() > 0) {
}
...and this is the query
QList<_RData> DBRManager::ReadRData(QString tbName, QString dbName)
{
QList<_RData> records;
QSqlQuery query(QSqlDatabase::database(dbName));
query.setForwardOnly(true);
query.exec("DSQLITE_THREADSAFE=2");
query.exec("SELECT * FROM " + tbName);
while (query.next()) {
_RData data;
data.id = query.value("id").toInt();
data.type = query.value("type").toInt();
records.append(data);
}
query.finish();
return records;
}