The Theory In theory, when a thread tries to lock a mutex and it does not succeed, because the mutex is already locked, it will go to sleep, immediately allowing another thread to run. It will continue to sleep until being woken up, which will be the case once the mutex is being unlocked by … Read more
I want to make sure this is out there, because it’s so hard to get right: using System.Runtime.InteropServices; //GuidAttribute using System.Reflection; //Assembly using System.Threading; //Mutex using System.Security.AccessControl; //MutexAccessRule using System.Security.Principal; //SecurityIdentifier static void Main(string[] args) { // get application GUID as defined in AssemblyInfo.cs string appGuid = ((GuidAttribute)Assembly.GetExecutingAssembly(). GetCustomAttributes(typeof(GuidAttribute), false). GetValue(0)).Value.ToString(); // unique id for … Read more
A lock allows only one thread to enter the part that’s locked and the lock is not shared with any other processes. A mutex is the same as a lock but it can be system wide (shared by multiple processes). A semaphore does the same as a mutex but allows x number of threads to … Read more
Here is a very good article regarding the Mutex solution. The approach described by the article is advantageous for two reasons. First, it does not require a dependency on the Microsoft.VisualBasic assembly. If my project already had a dependency on that assembly, I would probably advocate using the approach shown in another answer. But as … Read more
When I am having a big heated discussion at work, I use a rubber chicken which I keep in my desk for just such occasions. The person holding the chicken is the only person who is allowed to talk. If you don’t hold the chicken you cannot speak. You can only indicate that you want … Read more
They are NOT the same thing. They are used for different purposes! While both types of semaphores have a full/empty state and use the same API, their usage is very different. Mutual Exclusion Semaphores Mutual Exclusion semaphores are used to protect shared resources (data structure, file, etc..). A Mutex semaphore is “owned” by the task … Read more