{"id":849,"date":"2023-03-10T15:31:48","date_gmt":"2023-03-10T08:31:48","guid":{"rendered":"https:\/\/csharptutorial.net\/?page_id=849"},"modified":"2023-03-22T10:40:42","modified_gmt":"2023-03-22T03:40:42","slug":"csharp-lock","status":"publish","type":"page","link":"https:\/\/www.csharptutorial.net\/csharp-concurrency\/csharp-lock\/","title":{"rendered":"C# Lock"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you’ll learn how to use the C# lock<\/code> statement to prevent race conditions and ensure thread safety when multiple threads access shared resources.<\/p>\n\n\n\n

Race conditions<\/h2>\n\n\n\n

Let’s start with a simple program:<\/p>\n\n\n

int<\/span> counter = 0<\/span>;\nvoid<\/span> Increase<\/span>(<\/span>)<\/span>\n{\n    for<\/span> (int<\/span> i = 0<\/span>; i < 1000000<\/span>; i++)\n    {\n        counter++;\n    }\n    Console.WriteLine(\"The counter is \"<\/span> + counter);\n}\n\nTask.Run(() => Increase());\nTask.Run(() => Increase());\n\nConsole.ReadLine();<\/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 a variable counter<\/code> and initialize it to zero.<\/p>\n\n\n\n
Second, define the Increase()<\/code> method that adds one to the counter<\/code> variable 1 million times and displays the final value of the counter to the console.<\/p>\n\n\n\n
Third, create two tasks that run in separate threads<\/a>. Each task executes the Increase()<\/code> method to increase the counter<\/code> variable.<\/p>\n\n\n\n
Because both tasks modify the counter<\/code> variable concurrently, it has a risk of race conditions and synchronization problems.<\/p>\n\n\n\n
When the program increases the variable counter<\/code>, it carries three steps:<\/p>\n\n\n\n