concurrent-collections

I am trying to re-write some code using Dictionary to use ConcurrentDictionary. I have reviewed some examples but I am still having trouble implementing the AddOrUpdate function. This is the original code: dynamic a = HttpContext; Dictionary<int, string> userDic = this.HttpContext.Application["UserSessionList"] as Dictionary<int, String>; if (userDic != null) { if (useDic.ContainsKey(authUser.UserId)) { userDic.Remove(authUser.UserId); } } else { userDic = new Dictionary<int,string>(); } userDic.Add(authUser.UserId, a.Session.SessionID.ToString()); this.HttpContext.Application["UserDic"] =

Before I started a project, I wrote a simple test to compare the performance of ConcurrentBag from (System.Collections.Concurrent) relative to locking & lists. I am extremely surprised that ConcurrentBag is over 10 times slower than locking with a simple List. From what I understand, the ConcurrentBag works best when the reader and writer is the same thread. However, I hadn't thought it's performance would be so much worse than traditional locks. I have run a test with two Parallel for loops writing to and reading from a list/bag. However, the write by itself shows a huge difference: private

I am trying to figure out what the best way of working with a queue will be. I have a process that returns a DataTable. Each DataTable, in turn, is merged with the previous DataTable. There is one problem, too many records to hold until the final BulkCopy (OutOfMemory). So, I have determined that I should process each incoming DataTable immediately. Thinking about the ConcurrentQueue<T> ...but I don't see how the WriteQueuedData() method would know to dequeue a table and write it to the database. For instance: public class TableTransporter { private ConcurrentQueue<DataTable> tableQueue = new

How does SynchronizedCollection<T> and the concurrent collections in the System.Collections.Concurrent namespace differ from each other, apart from Concurrent Collections being a namespace and SynchronizedCollection<T> being a class? SynchronizedCollection<T> and all of the classes in Concurrent Collections provide thread-safe collections. How do I decide when to use one over the other, and why? The SynchronizedCollection<T> class was introduced first in .NET 2.0 to provide a thread-safe collection class. It does this via locking so that you essentially have a List<T> where every access is