Re: Distributed Reader-Writer Mutex 1.0

From:

"aminer" <aminer@videotron.ca>

Newsgroups:

comp.lang.c++

Date:

Thu, 13 Sep 2012 14:47:29 -0500

Message-ID:

<k2t9o8$3p9$1@dont-email.me>

Hello,

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
1.02 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() .

Thank you,
Amine Moulay Ramdane.

"aminer" <aminer@videotron.ca> wrote in message
news:k2q483$jd7$2@dont-email.me...

Hello,

Distributed Reader-Writer Mutex 1.0

Description:

Distributed Reader-Writer Mutex, based on the Dmitry Vyukov
C++ Distributed Reader-Writer Mutex , I have included the following
Reader-Writer Mutexes inside this Distributed Reader-Writer mutex:
TOmniMREW a light weight MREW that is very fast and
TMultiReadExclusiveWrite from JCL and now both of them
can scale better, and i have modified a little bit the Dmitry Vyukov
Distributed Reader-Writer Mutex, i have not used GetCurrectProcessor()
but i have used GetCurrectThreadID() like this:
nbr := getcurrentthreadid mod proc_count; 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 1.0
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(1000);

You have four methods:

procedure wlock; // like the EnterWriteLock of TOmniMREW
procedure wunlock; // like the ExitWriteLock
procedure rlock; // like EnterReadLock
procedure runlock; // like the ExitReadLock

and you have to pass the number of
MREWs(multiple-readers-exclusive-writer)
to the constructor like this:

drw:=TDRWLOCK.create(1000); // here we are creating 1000 MEWs

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 use -DDelphi

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 1.0 from:

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

Thank you,
Amine Moulay Ramdane.