Updated

EonaCat.DnsTester/Helpers/UrlHelper.cs

@@ -4,6 +4,7 @@ using System.Linq;
 using System.Net;
 using System.Security.Cryptography;
 using System.Text.RegularExpressions;
+using System.Threading.Tasks;
 
 namespace EonaCat.DnsTester.Helpers
 {
@@ -12,7 +13,7 @@ namespace EonaCat.DnsTester.Helpers
         private static readonly RandomNumberGenerator _randomNumberGenerator = RandomNumberGenerator.Create();
         public static event EventHandler<string> Log;
 
-        public static void GetRandomUrls(ref List<string> urlList, int totalUrls)
+        private static async Task<List<string>> GetRandomUrls(int totalUrls)
         {
             var letters = GetRandomLetters();
 
@@ -30,8 +31,7 @@ namespace EonaCat.DnsTester.Helpers
 
             Random rand = new Random();
 
-            List<string> urls = urlList;
+            List<string> urls = new List<string>();
-
             while (urls.Count < totalUrls)
             {
                 int index = rand.Next(searchEngineUrls.Count);
@@ -73,6 +73,8 @@ namespace EonaCat.DnsTester.Helpers
                             }
                         }
                     }
+
+                    await Task.Delay(100);
                 }
                 catch (Exception ex)
                 {
@@ -85,9 +87,27 @@ namespace EonaCat.DnsTester.Helpers
                 }
             }
 
-            urlList = urls;
+            var urlText = "url" + (urls.Count > 1 ? "'s" : string.Empty);
-            var urlText = "url" + (urlList.Count > 1 ? "'s" : string.Empty);
+            SetStatus($"{urls.Count} random {urlText} found");
-            SetStatus($"{urlList.Count} random {urlText} found");
+            return urls;
+        }
+
+        public static async Task<List<string>> RetrieveUrls(int numThreads, int numUrlsPerThread)
+        {
+            Task[] tasks = new Task[numThreads];
+
+            List<string> urlList = new List<string>();
+
+            // start each thread to retrieve a subset of unique URLs
+            for (int i = 0; i < numThreads; i++)
+            {
+                tasks[i] = Task.Run(async () => urlList.AddRange(await GetRandomUrls(numUrlsPerThread)));
+            }
+
+            // wait for all threads to complete
+            await Task.WhenAll(tasks);
+
+            return urlList;
         }
 
         private static string GetRandomLetters()

EonaCat.DnsTester/MainForm.Designer.cs

@@ -60,10 +60,13 @@
             txtResolveIP = new System.Windows.Forms.TextBox();
             label5 = new System.Windows.Forms.Label();
             label1 = new System.Windows.Forms.Label();
+            label2 = new System.Windows.Forms.Label();
+            numericUpDown2 = new System.Windows.Forms.NumericUpDown();
             panel1.SuspendLayout();
             ((System.ComponentModel.ISupportInitialize)numericUpDown1).BeginInit();
             panel2.SuspendLayout();
             panel3.SuspendLayout();
+            ((System.ComponentModel.ISupportInitialize)numericUpDown2).BeginInit();
             SuspendLayout();
             // 
             // RunTest
@@ -81,6 +84,8 @@
             // panel1
             // 
             panel1.BackColor = System.Drawing.SystemColors.ControlLight;
+            panel1.Controls.Add(numericUpDown2);
+            panel1.Controls.Add(label2);
             panel1.Controls.Add(comboBox1);
             panel1.Controls.Add(numericUpDown1);
             panel1.Controls.Add(label3);
@@ -380,6 +385,25 @@
             label1.TabIndex = 66;
             label1.Text = "Resolve ip address:";
             // 
+            // label2
+            // 
+            label2.AutoSize = true;
+            label2.Location = new System.Drawing.Point(566, 228);
+            label2.Name = "label2";
+            label2.Size = new System.Drawing.Size(201, 41);
+            label2.TabIndex = 60;
+            label2.Text = "Total Threads:";
+            // 
+            // numericUpDown2
+            // 
+            numericUpDown2.Location = new System.Drawing.Point(804, 228);
+            numericUpDown2.Maximum = new decimal(new int[] { 1000000000, 0, 0, 0 });
+            numericUpDown2.Minimum = new decimal(new int[] { 1, 0, 0, 0 });
+            numericUpDown2.Name = "numericUpDown2";
+            numericUpDown2.Size = new System.Drawing.Size(120, 47);
+            numericUpDown2.TabIndex = 61;
+            numericUpDown2.Value = new decimal(new int[] { 5, 0, 0, 0 });
+            // 
             // MainForm
             // 
             AutoScaleDimensions = new System.Drawing.SizeF(240F, 240F);
@@ -404,6 +428,7 @@
             panel2.ResumeLayout(false);
             panel3.ResumeLayout(false);
             panel3.PerformLayout();
+            ((System.ComponentModel.ISupportInitialize)numericUpDown2).EndInit();
             ResumeLayout(false);
         }
 
@@ -439,6 +464,8 @@
         private System.Windows.Forms.TextBox txtResolveIP;
         private System.Windows.Forms.Label label5;
         private System.Windows.Forms.Label label1;
+        private System.Windows.Forms.NumericUpDown numericUpDown2;
+        private System.Windows.Forms.Label label2;
     }
 }
 

EonaCat.DnsTester/MainForm.cs

@@ -46,10 +46,13 @@ namespace EonaCat.DnsTester
             List<string> urls = new List<string>();
             SetupView();
 
-            await Task.Run(() =>
+
-            {
+            int numThreads = (int)numericUpDown2.Value; // number of concurrent threads to use
-                UrlHelper.GetRandomUrls(ref urls, (int)numericUpDown1.Value);
+            int maxUrls = (int)numericUpDown1.Value; // maximum number of unique URLs to retrieve
-            });
+            int numUrlsPerThread = maxUrls / numThreads;
+
+
+            urls = await UrlHelper.RetrieveUrls(numThreads, numUrlsPerThread);
             AddUrlToView(urls);
 
 
@@ -195,13 +198,15 @@ namespace EonaCat.DnsTester
             DnsHelper.OnLog += DnsHelper_OnLog;
 
             for (int i = 0; i < urlsTotal; i++)
+            {
+                await Task.Run(async () =>
                 {
                     var currentUrl = urls[i];
 
                     await ExecuteDns1(recordType, dnsAddress1, currentUrl, dnsId1, i);
-                if (!chkDns2.Checked) continue;
+                    if (!chkDns2.Checked) return;
                     await ExecuteDns2(recordType, dnsAddress2, currentUrl, dnsId2, i);
-
+                });
                 await Task.Delay(100);
             }
         }
@@ -279,7 +284,8 @@ namespace EonaCat.DnsTester
                     $"ResourceRecord: Name: {answer.Name} : Type : {answer.Type} : Data :  {answer.Data}");
             }
 
-
+            ResultView.Invoke(() =>
+            {
                 for (int i = 0; i < ResultView.Items.Count; i++)
                 {
                     foreach (var answer in dnsResponse.Answers)
@@ -318,6 +324,7 @@ namespace EonaCat.DnsTester
                         }
                     }
                 }
+            });
         }
 
         private async void btnResolveIP_Click(object sender, EventArgs e)