CODEWITHSUNDEEP
c#multithreading
Petr
Petr

Reputation: 183

c# Create various number of threads

I have a method which creates different number of requests according to user's input. For each input I have to create an instance of an object and run method from that object in new thread. It means I never know, how many threads I will need. And later I will have to access data from each instance that I created before.

So the question is: How can I create different number of requests (and for each request one thread) according to user's input?

An example:

userInput = [start, end, start2, end2, start3, end3]

//for each pair Start-end create instance with unique name or make it other way accessible
Request req1 = new Request('start', 'end')
Request req2 = new Request('start2', 'end2')
Request req3 = new Request('start3', 'end3')

//create thread for each instance
Thread t1 = new Thread(new ThreadStart(req1.GetResponse));
t1.Start();
Thread t2 = new Thread(new ThreadStart(req2.GetResponse));
t2.Start();
Thread t3 = new Thread(new ThreadStart(req3.GetResponse));
t3.Start();

//get data from each instance
string a = req1.result
string b = req2.result
string c = req3.result

Upvotes: 0

Views: 658

Answers (3)

ebb
ebb

Reputation: 9387

You should NOT create a new thread per Request. Instead take advantage of the ThreadPool, either by using TPL, PLINQ or ThreadPool.QueueUserWorkItem.

An example of how you could do it with PLINQ:

public static class Extensions
{
    public static IEnumerable<Tuple<string, string>> Pair(this string[] source)
    {
        for (int i = 0; i < source.Length; i += 2)
        {
            yield return Tuple.Create(source[i], source[i + 1]);
        }
    }
}

class Program
{
    static void Main(string[] args)
    {
        var userinput = "start, end, start2, end2, start3, end3, start4, end4";

        var responses = userinput 
                        .Replace(" ", string.Empty)
                        .Split(',')
                        .Pair()
                        .AsParallel()
                        .Select(x => new Request(x.Item1, x.Item2).GetResponse());

        foreach (var r in responses)
        {
            // do something with the response
        }

        Console.ReadKey();
    }
}

Upvotes: 1

Reed Copsey
Reed Copsey

Reputation: 564811

In .NET 4, this could be done via Task<T>. Instead of making a thread, you'd write this as something like:

Request req1 = new Request("start", "end");
Task<string> task1 = req1.GetResponseAsync(); // Make GetResponse return Task<string>

// Later, when you need the results:
string a = task1.Result; // This will block until it's completed.

You'd then write the GetRepsonseAsync method something like:

public Task<string> GetRepsonseAsync()
{
     return Task.Factory.StartNew( () =>
     {
          return this.GetResponse(); // calls the synchronous version
     });
}

Upvotes: 2

Darin Dimitrov
Darin Dimitrov

Reputation: 1039398

If you are using .NET 3.5 or lower you could use the ThreadPool.QueueUserWorkItem method and if you are using .NET 4.0 use the TPL.

Upvotes: 1

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