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Distributed Reader-Writer Mutex 1.1

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Hello,


Distributed Reader-Writer Mutex was updated to version 1.1 , in this new 
version it works both across processes and threads.


Description:

Distributed Reader-Writer Mutex, based on the Dmitry Vyukov C++ Distributed 
Reader-Writer Mutex , that works across processe and threads, I have 
included the following Reader-Writer Mutexes inside this Distributed 
Reader-Writer mutex:

TMREW a light weight MREW lock (multiple-readers-exclusive-writer lock) that 
is very fast and that works across processes and threads and 
TMultiReadExclusiveWrite from JCL and now both of them can scale better, and 
i have modified the Dmitry Vyukov Distributed Reader-Writer Mutex, in the 
first version i have not used GetCurrentProcessor() but i have used 
GetCurrentThreadID(), and i have also provided you with a second version 
that scales better, to be able to use the second version please use the 
version2 inside defines.inc, i have given you a test.pas example for the 
first version and test1.pas for the second version, but don't forget to use 
version2 inside defines.inc, to use the second version just uncomment the 
version2 inside defines.inc and comment version1. I have also done a cache 
line alignement in TOmniMREW, this has allowed Drwlock to scale better.

I have provided you with the source code, please take a look at the source 
code to understand better.The Object Pascal Distributed Reader-Writer Mutex 
is based on the following C++ Distributed Reader-Writer Mutex by Dmitry 
Vyukov, read more here:

http://www.1024cores.net/home/lock-free-algorithms/reader-writer-problem/distributed-reader-writer-mutex

I have also modified the Dmitry Vyukov's Distributed Reader-Writer Mutex  to 
use a variable number of MREWs, you can pass the number of MREWs to the 
constructor like this:
drw:=TDRWLOCK.create(100);
You have four methods:
procedure wlock; // same as EnterWriteLock of TOmniMREW
procedure wunlock; // same as ExitWriteLock
procedure rlock; // same as EnterReadLock
procedure runlock; // same as ExitReadLock

and you have to pass the number of MREWs(multiple-readers-exclusive-writer) 
to the constructor like this:
drw:=TDRWLOCK.create(200); // here we are creating 200 MEWs
Here is some scalability numbers:

I have used TOmniMREW of the Omnithread library and used only 
EnterReadLock() and ExitReadLock() with four threads on a quad cores and 
TOmniMREW gave a negative scalability of -5.51x

And when i have used the second version of Distributed Reader-Writer Mutex 
using only rlock() and runlock() , it gave me +3.94x scalability with four 
threads on four cores. So now it's scaling.

And about the second version , don't forget to initialize the number  that 
you pass to rlock() and runlock()  to 0 before calling  rlock() and 
runlock() .

In the previous versions i have aligned the array elements on cache line 
bounderies like have done Dmitry Vyukov, and when i have tested the second 
version it didn't work correctly , so i have thought about that and after 
that i have decided to not align the array elements on cache line bounderied 
but just add a cache line padding to TOmniMREW and this time it has worked 
perfectly and now the second version is scaling perfectly..

Language: FPC Pascal v2.2.0+ / Delphi 7+: http://www.freepascal.org/
Operating Systems: Win and Linux (x86).
Required FPC switches: -O3 -Sd -dFPC -dWin32 -dFreePascal
-Sd for delphi mode....
Required Delphi switches: -DMSWINDOWS -$H+
For Delphi 5,6,7 use -DDelphi
For Delphi 2005,2006,2007,2009,2010+ use the switch -DDELPHI2005+
And inside defines.inc you can use the following defines:
{$DEFINE CPU32} for 32 bits systems
{$DEFINE CPU64} for 64 bits systems
{$DEFINE TOmniMREW} to use Omnithread MREW

{$DEFINE TMultiReadExclusiveWrite} to use the jcl TMultiReadExclusiveWrite



You can download Distributed Reader-Writer Mutex 1.1 from:

http://pages.videotron.com/aminer/




Thank you,
Amine Mouklay Ramdane.

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Thread

Distributed Reader-Writer Mutex 1.1 "aminer" <aminer@toto.com> - 2012-11-28 16:21 -0600
  Re: Distributed Reader-Writer Mutex 1.1 "aminer" <aminer@toto.com> - 2012-11-28 20:47 -0600
    Re: Distributed Reader-Writer Mutex 1.1 Anonymous <nobody@remailer.paranoici.org> - 2012-11-29 15:55 +0000
  Re: Distributed Reader-Writer Mutex 1.1 "aminer" <aminer@toto.com> - 2012-11-28 21:08 -0600
  Re: Distributed Reader-Writer Mutex 1.1 "aminer" <aminer@toto.com> - 2012-11-29 10:59 -0600
    Re: Distributed Reader-Writer Mutex 1.1 Wilfried März <Wilfried.Maerz@gmx.at> - 2012-11-29 20:25 +0100

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