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Re: Parallelhashlist was updated to version 1.41 ...

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Hello,


I have done some scalability tests on parallelhashlist 1.41
on an Intel Core 2 Quad Q6600..

Using 4 threads on 4 cores using the find()  method i had a perfect scaling 
of 4X .

Using 4 threads on 4 cores using the Add()  method i had a scaling of 3.4X



Regards,
Amine Moulay Ramdane.



"aminer" <aminer@videotron.ca> wrote in message 
news:jq67al$4i9$1@dont-email.me...
>
> Hello all,
>
>
> I have updated parallelhashlist to version 1.41..
>
>
> I have modified parallelhashlist to use 128 locks, but you
> have to use a hashsize in power of 2 and greater to 1000,
> how do you pass a hashsize in power of 2  to the constructor?
> by using shl operation like this
>
>
> trait:=TCaseinsensitiveTraits.create;;
> hash1:=TParallelHashList.create(trait,1 shl 25);
>
>
> Why do you have to use a power of 2 ?
>
>
> Please read this:
>
>
> Power-of-Two Hash Table Size
>
>
> "Any data structures 101 book will say choose a prime for the
> number of buckets, so that the bucket's index can easily be computed
> by h(k) = k mod m, where k is the key value and m is the bucket size.
> While this approach is straight-forward, there are a number of issues
> with it, including slow modulo performance. ConcurrentHashMap instead
> uses a power-of-two rule"
>
> http://work.tinou.com/2008/09/performance-optimization-in-concurrenthashmap.html
>
>
>
> I am using modulo functions inside parallelhashlist, and using a number of 
> locks
> in power of 2, so you have to use hashsize in power of 2 ,  this will make 
> the
> modulo function of the delphi and freepascal compilers 10X faster.
>
>
> You can download parallelhashlist version 1.41 from:
>
> http://pages.videotron.com/aminer/
>
>
>
>
> Thank you.
>
> Amine Moulay Ramdane.
>
>
>
> 

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Parallelhashlist was updated to version 1.41 ... "aminer" <aminer@videotron.ca> - 2012-05-30 18:34 -0500
  Re: Parallelhashlist was updated to version 1.41 ... "aminer" <aminer@videotron.ca> - 2012-05-30 18:38 -0500
  Re: Parallelhashlist was updated to version 1.41 ... "aminer" <aminer@videotron.ca> - 2012-05-30 18:46 -0500
  Re: Parallelhashlist was updated to version 1.41 ... "aminer" <aminer@videotron.ca> - 2012-06-02 18:38 -0500
    Re: Parallelhashlist was updated to version 1.41 ... "aminer" <aminer@videotron.ca> - 2012-06-02 18:52 -0500
      Re: Parallelhashlist was updated to version 1.41 ... "aminer" <aminer@videotron.ca> - 2012-06-02 18:56 -0500
  Re: Parallelhashlist was updated to version 1.41 ... "aminer" <aminer@videotron.ca> - 2012-06-02 18:40 -0500

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