Thread Safe Singleton Segmentation Fault

[D_Drmmr]

In GetInstance you access m_DbManager unsynchronized, so to make it thread safe, you should change it to.

ClsSqliteDatabaseManager* ClsSqliteDatabaseManager::GetInstance()
{
    unique_lock<mutex> lock(m_Mutex);
    while (m_DbManager == 0)
    {
        m_CondVar.wait(lock);
    }

    return m_DbManager;
}

However, that still leaves the possibility of a deadlock if CreateInstance is not called. IMO this design is difficult to use correctly.

It's not clear to me how DeleteInstance should be used. Why does it take a parameter?
Also, if you want to explicitly create and delete your singleton, why not create it before any worker threads are created and delete it after all worker threads have finished. That way you don't need any synchronization, at least not for accessing the singleton.