[Lazarus] Threads in Lazarus code base
pascaldragon at googlemail.com
Mon Sep 20 16:09:50 CEST 2010
Am 20.09.2010 15:22, schrieb Dariusz Mazur:
> W dniu 2010-09-20 13:55, Mattias Gärtner pisze:
>> Zitat von Dariusz Mazur <darekm at emadar.com>:
>>>> Before using multi threading, try to use a better single threaded
>>>> algorithm. And when comparing multi with single threading speed, you
>>>> must not compare a multi threaded algorithm running single threaded,
>>>> a multi threaded algorithm with a good single threaded algorithm.
>>> I don;t talk about best solution of fibbonaci computing. But about
>>> possibility do deal with some class of task using multithreading.
>>> Its easy imagine task, which is hard to resolve with loops.
>> Of course.
>> I think, we both agree that CILK is a nice approach.
> Nice to hear this.
>> I just said, that there are not many multi threading examples that are
>> easy to read and are practical at the same time. Computing Fibonacci
>> numbers does not need multi threading.
> Most of programs are huge count of simple computing. There are many
> places, that things may run parallel without pain. But very often this
> places are computing short, thus very often overhead of starting thread
> is bigger than using second core.
You are aware that for using a second core you need a thread (no matter
how fancy a syntax construct hides it)? Thus for reducing the overhead
of creating a thread at least one thread per core must be created before
the first call of a "spawned" function/procedure.
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