background_process.cs

private ManualResetEvent mre = new ManualResetEvent(false);

void startBW() {
	BW = new BW(); //BW is BackgroundWorker class
	BW.RunWorkerCompleted += BW_RunWorkerCompleted;
	BW.ProgressChanged += BW_ProgressChanged;
	BW.RunWorkerAsync();

	//wait until it finishes
	mre.WaitOne();
}

void BW_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
	//if cancellation is pending in this thread, notify the child BW
	if (CancellationPending)
	{
		BW.CancelAsync();
	}
}

void BW_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
	//when everyting is set, raise flag so that execution will continue.
	mre.Set();
}