I was trying to create an integration test for my service where 100 clients would connect, login, send request, and log all responses for some configurable amount of time.

I was build a class for the client using async sockets and it works fine. I started them all up using Task and Task.Factory, sent the login, and posted receives every time I got data, until the time expired and then I called shutdown on them.

It seems these never really run in parallel. Sometimes I might get 35ish running at once, sometimes a little more. I assume the task scheduler is running them when it seems fit rather than all at once.

Now I understand that I cannot truly have 100 threads running simultaneous, but I want to guarantee that all 100 are started and that the OS is context switching back and forth attempting to execute them all.

In the end, I want to simulate a large number of clients connected to my service all getting a stream of data.

What construct do I use if Task does not work?

Current Attempt:

using System; using System.Collections.Generic; using System.Configuration; using System.Linq; using System.Text; using System.Threading.Tasks;  namespace IntegrationTests {     class Program     {         static void Main(string[] args)         {             string       server            = ConfigurationManager.AppSettings["server"];             int          port              = int.Parse(ConfigurationManager.AppSettings["port"]);             int          numClients        = int.Parse(ConfigurationManager.AppSettings["numberOfClients"]);             TimeSpan     clientLifetime    = TimeSpan.Parse(ConfigurationManager.AppSettings["clientLifetime"]);             TimeSpan     timeout           = TimeSpan.Parse(ConfigurationManager.AppSettings["timeout"]);             TimeSpan     reconnectInterval = TimeSpan.Parse(ConfigurationManager.AppSettings["reconnectInterval"]);             List<string> clientIds         = ConfigurationManager.GetSection("clientIds") as List<string>;              try             {                 // SNIP configure logging                  // Create the specified number of clients, to carry out test operations, each on their own threads                 Task[] tasks = new Task[numClients];                 for(int count = 0; count < numClients; ++count)                 {                     var index = count;                     tasks[count] = Task.Factory.StartNew(() =>                         {                             try                             {                                 // Reuse client Ids, if there are more clients then clientIds.                                 // Keep in mind that tasks are not necessarily started in the order they were created in this loop.                                 // We may see client id 1 be assigned client id 2 if another client was started before it, but we                                 // are using all clientIds                                 string clientId = null;                                 if (numClients < clientIds.Count)                                 {                                     clientId = clientIds[index];                                 }                                 else                                 {                                     clientId = clientIds[index % clientIds.Count];                                 }                                  // Create the actual client                                 Client client = new Client(server, port, clientId, timeout, reconnectInterval);                                 client.Startup();                                  // Will make an sync request issue a recv.                                 // Everytime we get a reponse, it will be logged and another recv will be posted.                                 // This will continue until shutdown is called                                 client.MakeRequest(symbol);                                  System.Threading.Thread.Sleep(clientLifetime);                                  client.Shutdown();                             }                             catch(Exception e)                             {                                 // SNIP - Log it                             }                         });                 }                 Task.WaitAll(tasks);             }             catch (Exception e)             {                 // SNIP - Log it             }         }     } }