BackgroundWorker and ManualResetEvent

Question

The task.

I have one method which runs two long-time functions inside.

Im not talking about locking objects here. These funcs are independent, only have same parameter which used in readonly.

I want one func to run inside thread.

private static ManualResetEvent mre = new ManualResetEvent(false);
private Result result;

{
 BackgroundWorker bw = new BackgroundWorker();
 bw.DoWork += new DoWorkEventHandler(bw_DoWork);
 bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bw_RunWorkerCompleted);
 bw.RunWorkerAsync(new BackgroundWorkerArgument(bitmap, image));

Rectangle rectangle = DetectRectangle(bitmapClone));
mre.WaitOne();
mre.Reset();

<another code, dont bother>
}

void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        result= (Result)e.Result;
    }

    void bw_DoWork(object sender, DoWorkEventArgs e)
    {
        BackgroundWorkerArgument argument = (BackgroundWorkerArgument)e.Argument;
        e.Result = CreateResult(argument.Bitmap, argument.Image);
        mre.Set();
    }

The problem.

<another code, dont bother> runs immediately after i do Set(). Its ok.

But bw_RunWorkerCompleted runs after that. This means result variable has null, but i want it contains the result of thread's function.

How to rework my code - result= (Result)e.Result must runs before next line to WaitOne() ?

If its not possible with BackgroundWorker maybe i need to use threads ? I'm using .NET 2.0.

Why are you using a `BackgroundWorker` if you're blocking your thread with `ManualResetEvent.WaitOut`? You're missing the point of `BackgroundWorker` — Peter Ritchie, Mar 19 '13 at 14:53
`bw_RunWorkerCompleted` tells you when the BGW is done, just do "" in there... — Peter Ritchie, Mar 19 '13 at 14:54
I just want to separate two functions to win about 10seconds. The results of both functions are used in the next code, so i cant go it without both functions completed — Alexander, Mar 19 '13 at 14:56
One func takes about 8 secs to run. Another - 10sec. 10+8=18 secs in main thread. I want to run 8 in main thread, and 10 in the another. so general process should be faster. — Alexander, Mar 19 '13 at 14:57
So i really think maybe BackgroundWorker is not the solution because RunWorkerCompleted runs in main thread and no guarantee it will run before another code in main thread. — Alexander, Mar 19 '13 at 15:01
ok, can you please show me the example how to run thread with parameters and return the result ? — Alexander, Mar 19 '13 at 15:08
if this isn't the question you want to ask, close it and ask another. — Peter Ritchie, Mar 19 '13 at 15:10

BackgroundWorker and ManualResetEvent

0 Answers0