[Interest] how to run 21 threads concurrently

[Samuel Rødal]

On 10/04/2012 03:21 PM, Sujan Dasmahapatra wrote:
> I am not able to run my threads concurrently please help.
> How can I  run 21 threads concurrently and get the job done by 8 cpus
> what I have in my machine.
>
> I am doing like this
> [code]
>
> std::vector<QFuture<void> > Threads;
> QFuture<void> Th;
>
> for(int z=0; z<21; z++)
> {
> Th = QtConcurrent::run(this,&UnrstParser,z);
> Thraeds.push_back(Th);
> }
> for(int th=0; th<Threads.size(); th++)
> {
>   if(Threads[th].isRunning())
> Threads[th].waitForFinished();
> Threads[th].cancel();
> }
> Threads.clear();
> [/code]
>
> With this first few threads are probably running but not all the
> threads. As it's supposed to generate some files by each thread which is
> not being generated. Please help.

My guess is that not all the threads will have started yet when you hit 
the loop, and so when you do if (Threads[th].isRunning()) it returns 
false and then you do Threads[th].cancel() which probably means it will 
never run. Just do Threads[th].waitForFinished() in the loop and nothing 
else.

--
Samuel