问题
My software will simulate a few hundred hardware devices, each of which will send several thousand reports to a database server.
Trying it without threading did not give very good results, so now it's time to thread.
Since I am load testing the d/b server, some of those transactions will succeed and a few may fail. The GUI of the main program needs to reflect this. How should the threads communicate their results back to the main program? Update global variables? Send a message? Or something lese?
Now, if I update only at the end of each thread then the GUI is going to look rather boring (and I can't tell if the program hung). It might be nice to update the GUI periodically. But that might cause contention, with threads waiting for other threads to update (for instance, if I am writing to global variables, I need a mutex, which will block each thread which is waiting to write).
I'm new to threading. How is this normally done? Perhaps the main program could poll the threads, instead of the threads iforming the main program?
回答1:
One way to organize this is for your threads to add messages to a thread-safe queue (e.g. a ConcurrentQueue) as they get data. To keep things simple you can have a timer thread in your UI that periodically dequeues the queued messages to a private list and then renders them. This design allows your threads to easily queue and forget messages with minimal contention, and for your UI to periodically update itself without blocking your writers too much (i.e. for only the period it takes to dequeue current messages to a private list).
Although you are attempting to simulate the load of hundreds of devices, using thread per device is not the way to model this as you can only run so many threads concurrently anyway.
来源：https://stackoverflow.com/questions/4816839/feedback-from-threads-to-main-program