Question

I am writing tracing class to find the execution time of modules/methods. I have a class like this

public class Trace
    {
        static Dictionary<string, Stopwatch> watches = null;

        static Trace()
        {
            Dictionary<string, Stopwatch> watches = new Dictionary<string, Stopwatch>();
        }

        public static void Start(string key, string losgMessage)
        {
            try
            {
                if (!watches.Keys.Contains(key))
                {
                    Stopwatch watch = new Stopwatch();
                    watch.Start();
                    watches.Add(key, watch);
                }
            }
            catch
            {
            }
        }

        public static void Stop(string key, Object logMessage, string sessionId)
        {
            try
            {

                if (!watches.Keys.Contains(key))
                {
                    Stopwatch watch = watches[key];
                    watch.Stop();
                    //log goes here
                }
            }
            catch
            {
            }
        }
    }

since wcf is multithreaded environment and the ‘watches’ static variable scope is application level, If some one(new rqst from the differnt client) tries to execute the same method with same key i will not consider it and trace it. So what would be the best option in this case. Any suggestion would be helpful.

edit : I am current appending sessionId with key. Cant i resolve this issue without session id

Answer 1

Can’t I resolve this issue without session Id

From the information provided, I would say no. If you have concurrent requests executing the same function call then you are going to get duplicate entries. The only way to avoid this is to ensure all keys are unique. I actually think using the session ID is required anyway, otherwise how can you map the function to the request?

Also, Dictionary isn’t thread-safe (at least for writes), I would recommend using a ConcurrentDictionary.