Use synchronous or asynchronous tasks to collect print counters

Question

I am trying to develop a process that performs the collection of some printers counters via SNMP protocol, I thought to use Threads to perform this process, refatorei to use tasks, but I do not know if I should use an async await for this task, in this case I find myself a little confused if I am developing this method in the best way. Follows code of method:

private void timer_Elapsed(object sender, ElapsedEventArgs e)
    {
        using (ImpressoraDAO dao = new ImpressoraDAO())
        {
            var impressoras = dao.Listar().ToList();
            var impressorasTasks = impressoras.Select(impressora =>
            {
                return Task.Factory.StartNew(() =>
                {
                    if (impressora.IsConected())
                    {
                        using (ContadorDAO contadorDao = new ContadorDAO())
                        {
                            var contador = new Contador();
                            contador.Id = DateTime.Now;
                            contador.ImpressoraId = impressora.Id;
                            contador.QuantidadePaginas = Convert.ToInt64(OperacaoSNMP.ObterObjetoOID(IPAddress.Parse(impressora.Ip), OID.CONTADADOR_TOTAL));
                            contadorDao.Adicionar(contador);
                        }
                    }
                });
            }).ToArray();

            Task.WhenAll(impressorasTasks);
        }
    }

How can I improve this code ? Should I let it so or would it be better to use an async await ?

Answer 1

In this case it might be better not to use Task. Tasks work best when Voce has operations I\O asynchronous. Because as the I\O not processed the CPU can continue to do other things.

One thing I noticed is that the method contadorDao.Adicionar(contador) may be poorly implemented. I don’t know what this method does. But if he does a database query then it would make sense for him to be asynchronous. And then Voce should use tasks.

A better approach to current code would be to use the Parallel.ForEach

var impressoras = dao.Listar().ToList();
Parallel.ForEach(impressoras, impressora => {
    if (impressora.IsConected())
    {
        using (ContadorDAO contadorDao = new ContadorDAO())
        {
            var contador = new Contador();
            contador.Id = DateTime.Now;
            contador.ImpressoraId = impressora.Id;
            contador.QuantidadePaginas = Convert.ToInt64(OperacaoSNMP.ObterObjetoOID(IPAddress.Parse(impressora.Ip), OID.CONTADADOR_TOTAL));
            contadorDao.Adicionar(contador);
        }
    }
});

You will ultimately have to resort to profiling techniques to see what the best performing approach is for your scenario.