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POExecuting a function that accesses global array on multiple threads
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  1. POExecuting a function that accesses global array on multiple threads
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    copied!<p>I have a function 'graph1' that calls another function as shown below. When I call </p> <pre><code>graph1threader(copy, date); </code></pre> <p>I get the answer I want, however this takes upwards of 30 seconds, so I tried using multithreading. However when I use</p> <pre><code>thread[copy] = new Thread(() =&gt; graph1threader(copy, date));//pass date,copy thread[copy].Start(); </code></pre> <p>I get no result i.e. the global variables hold only 0. Why is this? And how may I rectify this?</p> <pre><code>void graph1() { chart1.ChartAreas[0].AxisX.MajorGrid.Enabled = false; chart1.ChartAreas[0].AxisY.MajorGrid.Enabled = false; for (int k = 0; k &lt; 5; k++) { int copy = k; DateTime date = G.AddDays(copy); refValues[copy] = 0; threshValues[copy] = 0; y_Values[copy] = 0; y__Values[copy] = 0; yValues[copy] = 0; //task[copy] = new Task(() =&gt; graph1threader(copy, date));//pass date,copy //ask[copy].Start(); graph1threader(copy, date); } for (int j = 0; j &lt; 5; j++) { DateTime temp = G.AddDays(j); string temper = temp.ToShortDateString(); y__Values[j] = y__Values[j] - y_Values[j]; xNames[j] = temper; } chart1.Series[1].Points.DataBindXY(xNames, y_Values); chart1.Series[2].Points.DataBindXY(xNames, y__Values); chart1.Series[3].Points.DataBindXY(xNames, refValues); chart1.Series[4].Points.DataBindXY(xNames, threshValues); chart1.Series[5].Points.DataBindXY(xNames, yValues); } void graph1threader(int x, DateTime date) { DBConnect A = new DBConnect(); List&lt;string&gt;[] list = new List&lt;string&gt;[4]; list = A.mandetselect(); int numberofmen = A.Countmandet(); string[] man_name = list[0].ToArray(); string[] trade = list[1].ToArray(); string[] license = list[2].ToArray(); string[] training = list[3].ToArray(); string[] display_status = list[4].ToArray(); //string abc; List&lt;string&gt;[] lista = new List&lt;string&gt;[5]; List&lt;string&gt;[] listc = new List&lt;string&gt;[14]; for (int j = 0; j &lt; numberofmen; j++) { int flag = 0; if (!display_status[j].Equals("NO") &amp;&amp; (selection == "ALL" || (selection == "LAE" &amp;&amp; license[j] != "") || (selection == "NON LAE" &amp;&amp; license[j] == "") || (selection == "ALL AVIONICS" &amp;&amp; trade[j] == "Avionics") || (selection == "NON LAE AVIONICS" &amp;&amp; trade[j] == "Avionics" &amp;&amp; license[j] == "") || (selection == "LAE AVIONICS" &amp;&amp; trade[j] == "Avionics" &amp;&amp; license[j] != "") || (selection == "ALL AIRFRAMES" &amp;&amp; trade[j] == "Airframes") || (selection == "NON LAE AIRFRAMES" &amp;&amp; trade[j] == "Airframes" &amp;&amp; license[j] == "") || (selection == "LAE AIRFRAMES" &amp;&amp; trade[j] == "Airframes" &amp;&amp; license[j] != ""))) { refValues[x]++; threshValues[x] = 0.8 * refValues[x]; string abc = man_name[j].Replace(" ", "_"); int no_of_proj = A.Countproj(abc);//required lista = A.manprojselect(abc);//required string[] projname = lista[0].ToArray(); string[] country = lista[2].ToArray(); string[] startofproj = lista[3].ToArray(); string[] endofproj = lista[4].ToArray(); string Status = ""; listc = A.Select(); int numberc = A.Count();//number of projects, not required string[] nameofproj = listc[0].ToArray(); string[] status = listc[13].ToArray(); for (int l = 0; l &lt; A.Countproj(abc); l++) { for (int m = 0; m &lt; numberc; m++) { if (nameofproj[m] == projname[l]) { Status = status[m]; } } DateTime shuru = DateTime.ParseExact(startofproj[l], "dd-MM-yyyy hh:mm:ss", CultureInfo.InvariantCulture); DateTime anth = DateTime.ParseExact(endofproj[l], "dd-MM-yyyy hh:mm:ss", CultureInfo.InvariantCulture); if (date &gt;= shuru &amp;&amp; date &lt;= anth) { if (Status != "PLANNED" &amp;&amp; Status != "LO" &amp;&amp; flag == 0) { y_Values[x]++;//BASIC UTILISATION flag = 1; } if (Status == "IP" || Status == "OTD") y__Values[x]++;//EXCESS if (Status == "PLANNED") { yValues[x]++;//UNUTILISED } } } } } } </code></pre> <p>I came across multi-threading only recently. So excuse me if the code doesn't look very good. <code>threshValue[]</code>,<code>refValues[]</code>,<code>y_Values[]</code>, <code>y__Values[]</code>, <code>yValues[]</code> are all global variables</p>
 

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