Threads synchronization

[Logmaster]

Hi,

I am new to C# and have just recently started to use threads.

I would like to create an application that will do the following:
1. Have a form which will act as the main thread.
2. Have additional N threads that will perform the same tasks, on different databases or different data ranges.
3. Once the N threads mentioned in paragraph 2 finish, I would like to to start a new thread which will purge duplicates.
4. Once the "PurgeDuplicates" thread completes, start an additional thread which will perform additional tasks.

I have created a form which executes the N parallel threads mentioned in paragraph 2. Theproblem is that I do not know how to wait until all the threads from paragraph 2 will end before executing the PurgeDuplicates threads. I have tried to use the Waitall() method and a while loop with IsAlive() (This is not my preferred solution since the form will become unresponsive during the update) however I guess that I am doing something wrong.

Can someone please help?

I have attached the code below:
-- Form Code --
ItemsUpdateTH MU1 = new ItemsUpdateTH(sample, 0, 79, 1);
MU1.myThread.Start();

ItemsUpdateTH MU2=new ItemsUpdateTH(sample,80,159,2);
MU2.myThread.Start();

--Item Update Code --
class ItemsUpdateTH
{
// I have removed all the content that is not relevant for this thread
public Thread myThread;
public ItemsUpdateTH (string[,] data, int var1,int var2,int var3)
{
this.var1=var1;
this.var2=var2;
this.data = data;
this.var3=var3;
myThread = new Thread(new ThreadStart(startUpdate));
}


private void startUpdate()
{
// Perform the tasks
}
}

THANKS,
Joe

 

[Aptitude]

Can I clarify exactly what the problem is? You say you tried something like this:

while (MU1.myThread.IsAlive && MU2.myThread.IsAlive)
{
}

Are you saying that:

a. This code failed with an error
b. This code failed to wait until the child threads finished
c. This code waited correctly, but the UI stopped responding

If a: What was the error you got?

If b: That would seem dead strange. Are you sure the treads ran correctly?

If c: The solution is to place a timer on your form and check the .IsAlive flag every time the timer fires.

 

[Logmaster]

Thanks Aptitude.

I found an error in my code. I have also found a detailed page with code samples of 2 ways to do what I want:

http://www.omegacoder.com/?p=35

Thanks Again!!!