My new algorithms of Scalable RWLocks using scalable counting networks version 4.1 are here

[Intelli2]

Hello,

My new algorithms of Scalable RWLocks using scalable counting networks
version 4.1 are here, i have provided you with the Windows and the Linux
versions.

You can download them from:

https://sites.google.com/site/aminer68/scalable-rwlock-using-scalable-counting-networks

Authors: Amine Moulay Ramdane.

Description:

I have ported the scalable counting network algorithm to Delphi and
FreePascal, and i have used it inside my following Scalable RWLOCKs
using scalable counting networks , here is the papers of the scalable
counting network algorithm:

http://people.csail.mit.edu/shanir/publications/AHS.pdf

and also read the following (the counting network is truly scalable,
please look at the graph inside the paper):

http://people.csail.mit.edu/shanir/publications/HLS.pdf

Counting networks are truly scalable and are a special type of balancer
networks which count.

I have provided with the following Scalable RWLOCKs using scalable
counting networks:

A fast, and scalable and lightweight Multiple-Readers Exclusive-Writer
Lock that is portable called LW_RWLock and a fast, and scalable and
starvation-free and lightweight Multiple-Readers-Exclusive-Writer Lock
that is portable called LW_RWLockX and that is FIFO fair on the writer
side and FIFO fair on the reader side and that is of course
Starvation-free, and also a fast a scalable
Multiple-Readers-Exclusive-Writer Lock that is portable called RWLock
and that doesn't spin-wait but uses my SemaMonitor so it is energy
efficient and also a fast and scalable and lightweight
Multiple-Readers-Exclusive-Writer Lock that is portable called RWLockX,
this one is FIFO fair on the writer side and FIFO fair on the reader
side and of course it is starvation-free and it doesn't spin-wait but
uses my portable SemaMonitor and portable event objects , so it is
energy efficient.

As you have noticed i have invented 4 variants of my scalable RWLock,
the ones that ends with an X in there names are FIFO fair on the writer
side and FIFO fair on the reader side and they are of course
starvation-free and they are suitable for reatime critical systems, the
others are not.

Why have i decided to come with scalable and starvation-free RWLocks,
cause you can have frequent reads and infrequent writes but from time to
time you can have frequent writes, so i think it is important to have a
scalable and starvation-free RWLock , this is why i have come up with
two variants of scalable and starvation-free RWLocks.

A Read/Write Lock is a performance improvement over a standard mutex for
cases where reads outnumber writes. with a Read/Write Lock multiple
simultaneous read locks may be held, but write locks are exclusively held.

The exclusive writing lock ensures that race conditions do not occur,
since if one client is writing to the data no other client may read or
write.

Also, the allowance for multiple simultaneous read locks decreases
resource contention since multiple readers can safely use the shared data.

This increases performance over a standard mutex for the assumed usage
pattern of frequent simultaneous reads and infrequent writes.

Language: FPC Pascal v2.2.0+ / Delphi 7+: http://www.freepascal.org/

Operating Systems: Windows, Mac OSX , Linux...

Required FPC switches: -O3 -Sd -dFPC -dFreePascal

-Sd for delphi mode....

Required Delphi switches: -DMSWINDOWS -$H+ -DDelphi

{$DEFINE CPU32} and {$DEFINE Windows32} for 32 bit systems

{$DEFINE CPU64} and {$DEFINE Windows64} for 64 bit systems

Thank you,
Amine Moulay Ramdane.