[Qt-interest] Too many files open error on Mac OS

[Kai Koehne]

On 9/29/2010 7:42 AM, ext Serge wrote:
> Hello,
>
> My QT 4.5 GUI program opens a lot of files. On windows it is working
> fine, but on Mac OS it receives error - too many files open.
> If i type in bash:
>
> ulimit -n
> 256
>
> I found out how to fix it:
>
> echo limit maxfiles 2048 1000000>  /etc/launchd.conf
> #reboot
> ulimit -n
> 2048
>
> I deliver program to users in dmg archive.
> They just mount it and launch program.
> It can be a problem for some of them to make such a tuning in bash.
>
> Can program itself increase number of files, it can open, without need
> to reboot?



main.cpp of QtCreator has following code to achieve this:

#ifdef Q_OS_MAC
     // increase the number of file that can be opened in Qt Creator.
     struct rlimit rl;
     getrlimit(RLIMIT_NOFILE, &rl);

     rl.rlim_cur = qMin((rlim_t)OPEN_MAX, rl.rlim_max);
     setrlimit(RLIMIT_NOFILE, &rl);
#endif

Regards

Kai

-- 
Kai Koehne
Software Engineer
Nokia, Qt Development Frameworks

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