Re: thread pool

From:
=?windows-1252?Q?Arne_Vajh=F8j?= <arne@vajhoej.dk>
Newsgroups:
comp.lang.java.programmer
Date:
Sat, 10 Jan 2015 22:20:16 -0500
Message-ID:
<54b1ebf4$0$288$14726298@news.sunsite.dk>
On 1/8/2015 8:46 AM, Philipp Kraus wrote:

Hello,

I'm not firm with Java 1.7 / 1.8 thread pool structure, so I need a
little help:

I have got a Collection of Collections of Runnables, so the Collections
must be processed in a sequential order, but the Runnable objects can be
processed in parallel. The next collection can be proccess if the
collection before is finished (join-wait structure). All collections
should be processed in a infinity loop, but the loop should be paused
after or before all collections been processed. In pseudo code:

class MainThread extends Thread
{
     threadpool p;

     void run()
     {
            while (true)
            {

                  thread can be paused

                  foreach collection c
                  {

                     p.add(c);
                     p.wait_until_all_finished();

                  }

                  thread can be paused

            }
    }
}

My question is, which thread structure can I used for this problem and
in which way can I create the main thread. The main thread can created
on program startup and shutdown on program shutdown. I have got around
100 of runnable collections and more than 10.000 elements on each
runnable collection. IMHO a normal thread object for my master thread
should be okay and a WorkStealingPool for the inner loop, but how I can
use this in the correct way?


If you have a:

List<List<Runnable>> tasks

then I think the easiest way to execute as specified is:

for(List<Runnable> tsklst : tasks)
tsklst.parallelStream().forEach(action -> action.run());

I am assuming Java 8.

Arne

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