Pour obtenir une clé
d'essai remplissez le formulaire ci-dessous
Demandez des tariffs
Nouvelle licence
Renouvellement de licence
--Sélectionnez la devise--
USD
EUR
RUB
* En cliquant sur ce bouton, vous acceptez notre politique de confidentialité

Free PVS-Studio license for Microsoft MVP specialists
To get the licence for your open-source project, please fill out this form
** En cliquant sur ce bouton, vous acceptez notre politique de confidentialité.

I am interested to try it on the platforms:
** En cliquant sur ce bouton, vous acceptez notre politique de confidentialité.

Votre message a été envoyé.

Nous vous répondrons à


Si vous n'avez toujours pas reçu de réponse, vérifiez votre dossier
Spam/Junk et cliquez sur le bouton "Not Spam".
De cette façon, vous ne manquerez la réponse de notre équipe.

>
>
Problems of 64-bit code in real program…

Problems of 64-bit code in real programs: FreeBSD

02 Fév 2009

While telling people about problems and difficulties of developing 64-bit applications I often hear in response: "You just should write programs well and there will be no problems". What only have we done trying to persuade people that this view is absurd! We wrote articles, gave examples but there still were those who would stick to their opinion.

Surfing recently through the net searching for discussions of problems relating to 64-bit, at some forum I came across a description of strange behavior of a program for reading files. This program couldn't read a file of more than 2 GB although the code was correct:

size_t size;
size = fread(...);

Investigation showed that the error was... inside fread function of FreeBSD!

It is difficult to believe in this that's why I will prove my words. You can see the code of fread function in the repository of FreeBSD source code http://svnweb.freebsd.org/:

size_t
fread(void * __restrict buf, size_t size,
        size_t count, FILE * __restrict fp)
{
  int ret;
  FLOCKFILE(fp);
  ret = __fread(buf, size, count, fp);
  FUNLOCKFILE(fp);
  return (ret);
}

Oh my God, how could one define ret variable as int? Of course it's absolutely incorrect. This error was corrected... only in December 2008:

size_t
fread(void * __restrict buf, size_t size,
        size_t count, FILE * __restrict fp)
{
  size_t ret;
  FLOCKFILE(fp);
  ret = __fread(buf, size, count, fp);
  FUNLOCKFILE(fp);
  return (ret);
}

It is astonishing that an error in FreeBSD was corrected only in the end of 2008. Perhaps 64-bit systems are not called-for yet?

Popular related articles
macOS 10.15 no longer supports 32-bit apps. What can you do?

Date: 15 Oct 2019

Author: Sergey Khrenov

On October 7, 2019, Apple released a new version of its Mac operating system, macOS Catalina. Version 10.15 contains many changes and improvements. One of the significant is the complete phasing out …
If the coding bug is banal, it doesn't mean it's not crucial

Date: 19 Avr 2017

Author: Andrey Karpov

Spreading the word about PVS-Studio static analyzer, we usually write articles for programmers. However, some things are seen by programmers quite one-sided. That is why there are project managers wh…
Detecting Overflows of 32-Bit Variables in Long Loops in 64-Bit Programs

Date: 22 Mar 2016

Author: Andrey Karpov

One of the problems that 64-bit software developers have to face is overflows of 32-bit variables in very long loops. PVS-Studio code analyzer is very good at catching issues of this type (see the Vi…
Is it possible to run 64-bit applications in a 32-bit OS?

Date: 08 Déc 2015

Author: Andrey Karpov

Nowadays 64-bit operating systems are very widespread. But 32-bit OS are still present on the market, in quite obvious quantities. A lot of modern program tools are developed to be run only in 64-bit…
How to Port a 9 Million Code Line Project to 64 bits?

Date: 03 Aoû 2015

Author: Evgeniy Ryzhkov, Ilya Ivanov

Our team has recently finished porting one pretty large project (9 million code lines, 300 Mbytes of source files) to the 64-bit platform. It took us one year and a half. Although we are not permitte…

Comments (0)

Next comments
Unicorn with delicious cookie
Nous utilisons des cookies pour améliorer votre expérience de navigation. En savoir plus
Accepter