Can't find MQ_PRIO_MAX in include
Hello, I'm trying to use some POSIX MQ on Debian. I tried my code on Debian, FreeBSD and Cygwin, and it went well. I encountered a problem on FreeBSD about the maximum priority, then I searched about a fixed maximum, and I found MQ_PRIO_MAX. On FreeBSD and Cygwin it works properly, but on Debian, I can't find the macro MQ_PRIO_MAX. Precisely : I included for the mq_attr definition, mq_open function, ... And MQ_PRIO_MAX seems to be defined in in POSIX explanations. So, I included , and Debian still can't find MQ_PRIO_MAX. I googled a little, and found it in ! But if I put "only" , mq_open, mq_close... are undefined. If I put and , mq_attr is redefined. If I put only , MQ_PRIO_MAX is undefined. How should I found MQ_PRIO_MAX correctly on Debian ? My CFLAGS are : -W -Wall -Werror -ansi -pedantic My LDFLAGS are : -lrt I'm working on a Debian Squeeze (2.6.32-042stab076.8 #1 SMP Tue May 14 20:38:14 MSK 2013 x86_64), with ldd (Debian EGLIBC 2.11.3-4) 2.11.3. Shouldn't MQ_PRIO_MAX be define in in the next releases ? Thank you in advance ! -- Fabrice BOISSIER // Metalman
Re: Can't find MQ_PRIO_MAX in include
linux-libc-dev and libc6-dev already installed, and the file /usr/include/linux/mqueue.h contains MQ_PRIO_MAX and the struct mq_attr. But the structure mq_attr in /usr/include/linux/mqueue.h is in conflict with the one declared in the /usr/include/mqueue.h (precisely in /usr/include/bits/mqueue.h that is included by /usr/include/mqueue.h) Either MQ_PRIO_MAX and some other constants should be defined in limits.h, or struct mq_attr shouldn't be defined twice. 2013/5/31 Neil Williams > On Fri, 31 May 2013 11:21:15 +0200 > Fabrice Boissier wrote: > > > macro MQ_PRIO_MAX. > > How should I found MQ_PRIO_MAX correctly on Debian ? > > > Debian Squeeze (2.6.32-042stab076.8 #1 SMP Tue May 14 > > 20:38:14 MSK 2013 x86_64), > > So a linux kernel, the match is: > > /usr/include/linux/mqueue.h:#define MQ_PRIO_MAX 32768 > > $ dpkg -S /usr/include/linux/mqueue.h > linux-libc-dev:amd64: /usr/include/linux/mqueue.h > > Ensure linux-libc-dev is installed and look for the .h in the linux/ > directory. > > > http://packages.debian.org/search?searchon=contents&keywords=mqueue.h&mode=path&suite=stable&arch=any > > -- > > > Neil Williams > = > http://www.linux.codehelp.co.uk/ > > -- Fabrice BOISSIER // Metalman Epita2012 - SRS root SRS (Fév 2011 - Fév 2012)
Re: Can't find MQ_PRIO_MAX in include
2013/5/31 Ben Hutchings > On Fri, 2013-05-31 at 11:21 +0200, Fabrice Boissier wrote: > > Hello, > [...] > > This is not a support forum for Linux development. But as people have > already started giving you silly answers: > I previously searched... and nearly nobody uses POSIX MQ (except QNX ?!). I previously asked on a Debian forum, and nobody could answer... Per POSIX, you cannot assume this macro (or any such constant limit) is > defined, and must use sysconf(_SC_MQ_PRIO_MAX) at run-time if it is not. > Personally, a twice declaration of a structure is probably not very very good... ok, that's none of my business, I don't criticize this point. But, the macro I was searching for is defined in a file, and as a third developper I can't directly access it during precompilation... why ? It seems nobody care about POSIX MQ, and it's a little puzzling that Debian doesn't show the macro in limits.h or mqueue.h, even if it's declared in some headers. My point was only to be sure if that was expectable or not. -- Fabrice BOISSIER // Metalman
