Re: IMPORTANT : BUDDY SYSTEM PROJECT ??????

[David Turner <turner@enst.fr>]

Graham Perkins wrote:
> 
> Eric , Chow Hoi Ka wrote:
> > Who know what is BUDDY SYSTEM in OS ????
> > Who have the information about BUDDY SYSTEM ???
> 
> The "Binary Buddy System" is used in some operating systems
> for managing the allocation of memory space to processes.
>

Well, it isn't only used in operating systems. It's just one of
the memory allocation scheme that was developped to try
outperforming the classic "best-fit" in terms of internal
fragmentation, external fragmentation, allocation speed,
or release speed, etc ..
 
> 
> You must read an operating system book to discover more detail.
>

I'd rather suggest this excellent survey :

  Dynamic Storage Allocation: A Survey and Critical Review.
  Paul R. Wilson, Mark S. Johnstone, Michael Neely, and David Boles.
  In International Workshop on Memory Management, Kinross, Scotland, 
  UK, September 1995. 

  Postcript is available online at :

    ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps

  It discusses many issues related to memory allocation, and
  compares the various known schemes ( of which buddy systems ).

  The survey seems to indicate that buddy systems aren't really great
  when compared to other schemes, even in terms of allocation and
  coalescing speed..

> > Who have some source codes in Ada, C/C++, Modula2 or Java of BUDDY
> > SYSTEM ????
> 
> The people who implement operating systems.  and they probably
> didn't use Modula-2 or Ada or C++ or Java

Well, I know of one RT-OS written in Ada (RTOS), one general purpose
OS written in Modula-3, and I wouldn't be surprised to learn that
someone tried to do that in C++ (even if the chances of failure
can be great if used without care).

Moreover, this isn't really an issue about languages, but algorithms,
which can all be implemented in any language (except maybe in Logo ?).
And the concepts are usually simple to understand to not need a very
long implementation..

Good luck, and good reading..

--  David "G" Turner  | ( The 'G' doesn't stand for 'Genius' ! )
--  turner @ enst.fr  |    student at Telecom ( Paris, France )
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