I’m developing an application multi-thread that needs to connect to an Informix DB.
I’m working with the CSDK 4.50 and c++ libraries.

I’m encountering issues with the connection. I didn’t find the way in which initialize a different connection for every thread.

here a simple snippet of code for replicate my issues

int main(int argc, char *argv[])
    {
        const constexpr int nthreads = 10;
        std::thread t[nthreads];

        for (int i = 0; i < nthreads; ++i) {
            t[i] = std::thread(printArt, conn, dbinfo, i);
        }

        for (int i = 0; i < nthreads; ++i) {
            t[i].join();
        }

        return 0;
    }

    void printArt(int i)
    {
        std::random_device rd; // obtain a random number from hardware
        std::mt19937 gen(rd()); // seed the generator
        std::uniform_int_distribution<> distr(2000, 5000); // define the range

        vector<string> result;

        ITDBInfo dbinfo;
        dbinfo.SetDatabase("eda");
        
        ITConnection conn;
        conn.Open(dbinfo)
        
        if (conn.Error()) {
            return;
        }

        conn.SetTransaction(ITConnection::Begin)
        
        ITCursor cursor(conn);
        
        if (!cursor.Prepare("select first 1 * from a_table;")) {
            conn.SetTransaction(ITConnection::ABORT);
            return;
        }

        if (!cursor.Open()) {
            conn.SetTransaction(ITConnection::ABORT);
            return;
        }

        std::this_thread::sleep_for(std::chrono::milliseconds(distr(gen)));

        ITRow* row = nullptr;
        while ((row = cursor.NextRow()) != nullptr) {
            string col0 = row->Column(0)->Printable().Data();
            string col1 = row->Column(1)->Printable().Data();

            cout << "[" << i << "] " << col0 << " | " << col1 << endl;

            row->Release();
        }

        conn.SetTransaction(ITConnection::Commit)

        conn.Close();

        return;
    }

The result of this execution is undefined, sometimes it goes ahead until the end, sometimes it crash with a core dumped.
When the program doesn’t crash it seems that only one query has result and print it. The expected result is to see 1 line printed from every query (thread).

I’ve linked the th prefixed libraries as suggested in this answer, the result is always the one described above.

Where is my mistake?