How to wait for a thread to finish execution in C#?

问题

I have a function that is called in rapid succession that has a open database connection. my issue is that before one database connection is closed, another instance of the function is called and i could possibly receive a deadlock in the database.

I have tried:

private static WaitHandle[] waitHandles = new WaitHandle[]
    {
        new AutoResetEvent(false)
    };

protected override void Broadcast(Data data, string updatedBy)
    {
        Action newAction = new Action(() =>
        {
        DataManagerFactory.PerformWithDataManager( 
            dataManager =>
            {
                // Update status and broadcast the changes
                data.UpdateModifiedColumns(dataManager, updatedBy);

                BroadcastManager.Instance().PerformBroadcast(
                    data,
                    BroadcastAction.Update,
                    Feature.None);
            },
            e => m_log.Error(ServerLog.ConfigIdlingRequestHandler_UpdateFailed() + e.Message));
            }
        );

        Thread workerThread = new Thread(new ThreadStart(newAction));
        ThreadPool.QueueUserWorkItem(workerThread.Start, waitHandles[0]);
        WaitHandle.WaitAll(waitHandles);
    }

but i recieve a thread error and the program freezes. It has something to do with the thread start function having no parameters i believe.

Thanks for any help

回答1:

This is how it's done. Create class that does the job:

public class MyAsyncClass
{

    public delegate void NotifyComplete(string message);
    public event NotifyComplete NotifyCompleteEvent;

    //Starts async thread...
    public void Start()
    {
        System.Threading.Thread t = new System.Threading.Thread(new System.Threading.ThreadStart(DoSomeJob));
        t.Start();
    }

    void DoSomeJob()
    {
        //just wait 5 sec for nothing special...
        System.Threading.Thread.Sleep(5000);
        if (NotifyCompleteEvent != null)
        {
            NotifyCompleteEvent("My job is completed!");
        }
    }
}

Now this is code from another class, that calls first one:

 MyAsyncClass myClass = null;


    private void button2_Click(object sender, EventArgs e)
    {
        myClass = new MyAsyncClass();
        myClass.NotifyCompleteEvent += new MyAsyncClass.NotifyComplete(myClass_NotifyCompleteEvent);
        //here I start the job inside working class...
        myClass.Start();
    }

    //here my class is notified from working class when job is completed...
    delegate void myClassDelegate(string message);
    void myClass_NotifyCompleteEvent(string message)
    {
        if (this.InvokeRequired)
        {
            Delegate d = new myClassDelegate(myClass_NotifyCompleteEvent);
            this.Invoke(d, new object[] { message });
        }
        else
        {
            MessageBox.Show(message);
        }
    }

Let me know if I need to explain some details.

Alternative to this is BackgroudWorker:

来源：https://stackoverflow.com/questions/13241888/how-to-wait-for-a-thread-to-finish-execution-in-c

标签

multithreading

concurrency

waithandle