Author: Daniel Shawul
Date: 07:49:10 11/09/04
Go up one level in this thread
On November 09, 2004 at 09:47:07, Anthony Cozzie wrote:
>On November 09, 2004 at 01:32:53, Daniel Shawul wrote:
>
>>hi
>>i don't know anything about multi threading,but i
>>have plan to make my engine a parallel searcher.
>>few basic questions
>>
>> 1.Can I program on a single CPU computer?or Do i need at least a dual?
>>
>> 2.if (1) is possible,can i be sure it works on a dual.
>>
>> 3.Do i need to write different code for different OS(windows and linux).
>> Or is it part of the C Language.
>> 4. Last but very important, where can i get a good tutorial(basic) on multi-
>> threading in c/c+=, or a good book.
>>
>>thanks in advance
>>daniel
>
>I am not sure I want to see a parallel DanChess, but here goes :)
Don't worry my plan is to make a ParDan 4x slower than normal;)
>
>The problem with parallel programming is all the race conditions: two cpus try
>to do something at the same time; who wins? In theory, I believe that the task
>switching of the OS will simulate 2 processors, but it will take WAY longer, so
>in practice you need a dual. The good news is that they are very cheap
>nowadays; just buy a P4 with HT.
>
That's what i had in mind.some kind of simulation for programming purpose
only. Well at least i can experiment with SMP theory in general, with out seeing
any result.
>For parallel programming most people use pthreads on linux or the windows api
>(beginthread/Createthread, EnterCriticalSection, etc) on windows.
I prefer writing windows only for now since i have no experience with
other OS.
> However, you
>will have to write spinlocks, because you don't want the OS to swap you out.
>You either write your own (its not that hard, and rather fun), or you can copy
>Crafty's; I believe Bob stole his from the linux kernel. Zappa uses CMPXCHG
>rather than XCHG (merely for amusement, read Herlihy's paper on wait-free
>synchronization), but its of course up to you.
>
>Lastly, i recommended ABDADA, simply because it is the easiest to implement.
I guess i will go on with ABDADA after i finish my threaded input polling
while pondering.
It
>doesn't give very good performance for large numbers of processors, but who has
>access to lots of processors anyway :) I did a full DTS implementation in Zappa
>to prove my manliness, but it still doesn't work on >2 procs, was a lot of work,
>and split-anywhere is only a few % faster than a Crafty style splitting
>algorithm, which is probably only a few % faster than ABDADA. I may get better
>results when I improve my move-ordering; we shall see.
>
>Good luck! If you have problems, you can always ask me, or Bob has about 500
Thanks very much. I will certainly do.
best wishes
daniel
>years of experience doing this :)
>
>anthony
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