C # Threads error the process can not access the file because that being used in another process

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C # Threads error the process can not access the file because that being used in another process

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#1 by (4 votes)

3

I am working on C # with threads but I can not print them in a txt because the error occurs:

The process can not access the file 'C: \ Users \ wuesi \ Desktop \ Data.txt' because it is being used in another process System.IO.IOException

namespace threads
{
    class Program
    {
        static void Main(string[] args)
        {
            productor hilo_Obj1 = new productor(); 
            productor hilo_Obj2 = new productor();
            productor hilo_Obj3 = new productor();

            Consumidor hilo_obj4 = new Consumidor(); 
            Receprto hilo_obj5 = new Receprto();

            Thread hilo_Uno = new Thread(new ThreadStart(hilo_Obj1.run)); 
            Thread hilo_Dos = new Thread(new ThreadStart(hilo_Obj2.run));
            Thread hilo_Tres = new Thread(new ThreadStart(hilo_Obj3.run));
            Thread hilo_Cuatro = new Thread(new ThreadStart(hilo_obj4.run_C));
            Thread hilo_Cinco = new Thread(new ThreadStart(hilo_obj5.Run_R)); 

            hilo_Uno.Start();  
            hilo_Dos.Start();   
            hilo_Tres.Start();
            hilo_Cuatro.Start();   
            hilo_Cinco.Start();
            Console.ReadLine();
        }
    }


    class productor : Consumidor
    {
        int M,i;
        public double dataqueue_a, dataqueue_i, dataqueue_c;

        public productor()
        {
            M = 5;
            i = 0;
            dataqueue_a = 0;
            dataqueue_c = 0;
            dataqueue_i = 0;
        }

        public void run()
        {
            do
            {
                Random aleatorio_C = new Random();//genero datos entre 97 y 122 para despues imprimirlos con el valor de ascii y generar datos char
                int a;
                for (i = 0; i < M; i++)
                {

                    a = aleatorio_C.Next(97, 122);
                    dataqueue_a = a;

                    if (dataqueue_a != 0)
                    {
                        dataqueue.Enqueue(dataqueue_a);

                    }
                }

                Random aleatorio_I = new Random();
                int b;
                for (i = 0; i < M; i++)
                {

                    b = aleatorio_I.Next(1, 50);
                    dataqueue_i = b;
                    if (dataqueue_i != 0)
                    {
                        dataqueue.Enqueue(dataqueue_i);
                    }
                }

                Random aleatorio_F = new Random();
                double c;
                for (i = 0; i < M; i++)
                {

                    c = aleatorio_F.NextDouble();
                    dataqueue_c = c;
                    if (dataqueue_c != 0)
                    {
                        dataqueue.Enqueue(dataqueue_c);
                    }
                }
            } while (dataqueue.Count == 45);

                semaforo = "Done";
                run_C();


        }        
 }



    class Consumidor:Receprto
    {
        public String semaforo;
        public Queue dataqueue = new Queue();

        public void run_C()
        {            
                while (dataqueue.Count > 0)
                {
                    if (sem == true)
                    {
                        sem = false;
                        str = (double)dataqueue.Dequeue();
                        Run_R();
                          sem = true;
                      }
                }

        }
    }
}

class Receprto
{
    public double str;
    public bool sem=true;
    StreamWriter sw = new StreamWriter("C:\Users\wuesi\Desktop\Datos.txt");

    public async void Run_R()
    {
        if (str != null)
        {
            Console.WriteLine(str);
            sw.Write(str);
        }
        sw.Close();
    }
}

c# hilos

asked by itsvan moreno 03.06.2018 в 00:20

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1 answer

Display data from a DataGridView column in float Duplicate data - Double inner join

score 4 · Accepted Answer

You have a career condition. When you initialize the threads, only one at a time can open StreamWriter and write to the file, otherwise it throws an error where there is another process that is using the file.

Try using lock . In essence, a lock blocks access to a certain algorithm if it detects that another process is accessing the 'locked' object :

class Receprto
{
    public double str;
    public bool sem=true;


    // objeto que servira como indicador si esta siendo accedido por otro hilo
    private static object _lockObject = new object();
    public async void Run_R()
    {
           lock(_lockObject)
           {
              StreamWriter sw = new StreamWriter("C:\Users\wuesi\Desktop\Datos.txt");
              // este codigo se ejecutara siempre y cuando
              // el objecto _lockObject este marcado como libre por el lock

              if (str != null)
              {
                Console.WriteLine(str);
                sw.Write(str);
              }
              sw.Close();
           }
    }
}

What it does is that it locks the input to the initialization of StreamWriter if another thread is accessing the block lock and when it ends, then the waiting thread enters the lock .