{"id":762,"date":"2023-03-06T15:30:55","date_gmt":"2023-03-06T08:30:55","guid":{"rendered":"https:\/\/csharptutorial.net\/?page_id=762"},"modified":"2023-03-20T13:45:59","modified_gmt":"2023-03-20T06:45:59","slug":"csharp-thread","status":"publish","type":"page","link":"https:\/\/www.csharptutorial.net\/csharp-concurrency\/csharp-thread\/","title":{"rendered":"C# Thread"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you’ll learn how to use the C# Thread<\/code> class to develop multi-threaded programs.<\/p>\n\n\n\n

Introduction to the C# Thread class<\/h2>\n\n\n\n

We’ll start by creating a simple program:<\/p>\n\n\n

using<\/span> System.Diagnostics;\nusing<\/span> static<\/span> System.Console;\n\n\nstatic<\/span> void<\/span> DoWork<\/span>(<\/span>)<\/span>\n{\n    WriteLine(\"Doing the work...\"<\/span>);\n    Thread.Sleep(1000<\/span>);\n    WriteLine(\"done\"<\/span>);\n}\n\nvar<\/span> watch = Stopwatch.StartNew();\n\nDoWork();\nDoWork();\n\n\nwatch.Stop();\nWriteLine($\"It took {watch.Elapsed.Seconds}<\/span> second(s) to complete.\"<\/span>);<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
Doing the work...\ndone\nDoing the work...\ndone\nIt took 2<\/span> second(s) to complete.<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
How it works.<\/p>\n\n\n\n
First, define the DoWork()<\/code> method that takes one second to run. The DoWork()<\/code> method uses the Sleep()<\/code> static method of the Thread<\/code> class to delay for one second.<\/p>\n\n\n\n
Second, use the Stopwatch<\/code> object to measure the running time of the program. The Startnew()<\/code> method of the Stopwatch<\/code> class initializes a Stopwatch<\/code> object, resets the elapsed time to zero, and starts measuring the time.<\/p>\n\n\n\n
Third, call the DoWork()<\/code> method twice.<\/p>\n\n\n\n
Finally, stop measuring the elapsed time and print out the time that it took to run.<\/p>\n\n\n\n
Because each DoWork()<\/code> method takes one second to complete, the whole program takes about 2 seconds which is as expected.<\/p>\n\n\n\n
Using the C# Thread class<\/h3>\n\n\n\n
To make the above program multi-threaded, you use the Thread<\/code> class. The steps for using the Thread<\/code> class are as follows:<\/p>\n\n\n\n
First, create a new instance of the Thread<\/code> class and pass a method to its constructor:<\/p>\n\n\n
var<\/span> t = new<\/span> Thread(method);<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
Second, call the Start()<\/code> method to start the execution of the thread:<\/p>\n\n\n
t.Start()<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
Third, call the Join()<\/code> method to wait for the thread to complete:<\/p>\n\n\n
t.Join()<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
The following example shows how to use the Thread<\/code> class to create a multithreaded program:<\/p>\n\n\n
using<\/span> System.Diagnostics;\nusing<\/span> static<\/span> System.Console;\n\n\nstatic<\/span> void<\/span> DoWork<\/span>(<\/span>)<\/span>\n{\n    WriteLine(\"Doing the work...\"<\/span>);\n    Thread.Sleep(1000<\/span>);\n    WriteLine(\"done\"<\/span>);\n}\n\nvar<\/span> watch = Stopwatch.StartNew();\n\nvar<\/span> t1 = new<\/span> Thread(DoWork);\nvar<\/span> t2 = new<\/span> Thread(DoWork);\n\n\n\/\/ start both threads<\/span>\nt1.Start();\nt2.Start();\n\n\/\/ wait for both threads completed<\/span>\nt1.Join();\nt2.Join();\n\n\nwatch.Stop();\nWriteLine($\"It took {watch.Elapsed.Seconds}<\/span> second(s) to complete.\"<\/span>);<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
Doing the work...\nDoing the work...\ndone\ndone\nIt took 1<\/span> second(s) to complete.<\/code><\/span>Code language:<\/span> C#<\/span> (<\/span>cs<\/span>)<\/span><\/small><\/pre>\n\n\n
In this example, the program took only one second to complete even though it calls the DoWork()<\/code> method twice. In other words, its speed is double in comparison with the program that uses a single thread.<\/p>\n\n\n\n
Passing arguments to the threads<\/h2>\n\n\n\n
To pass arguments to threads, you can:<\/p>\n\n\n\n