线程vs计时器vs服务

Question

I was reading this blog Easy Background Tasks about the badge system of some page called stackoverflow :P, so, in a comment says that they ended with a service that perform the task, but for example:

User performs action in time T1 This action depends of X number of users After time T2, you need to execute some db query and notify user(email or whatever)

I say this because of the real time experience, so the question here is, if you use threads, lets say you have 1000 users that perform actions, you will have 1000 waiting threads, so in some time, there will be reciclyng, or if the server shutsdown for some reason, you will lose all this tasks. Using a timer will end in the same situation

If you use a service you will lose the real time experience, for example in an online game.

So, how to deal with this kind of stuff?

Answer 1

You should be careful when using threads and signaling. The solution depends to the details of the scenario, but one of the scalable solutions is polling .

Based on your scenario, signaling between threads is not efficient as there's always a limited number of available threads in the threadpool. However, if you know the maximum number of users who will hold a thread ( depending on the game design ) , you can use signaling using WaitHandles ( AutoResetEvent and/or ManualResetEvent) to signal between threads. But make sure that you have increased the number of available threads in the pool in the Application_Start event handler of the Global.asax

            int availableThreads;

            int availablePorts;

            ThreadPool.GetAvailableThreads(out availableThreads, out availablePorts);

            ThreadPool.SetMinThreads(availableThreads, availablePorts);

Hope it helps.