01-14-2009
POSIX Message Queues
Quote:
Originally Posted by
pludi
ipcs and ipcrm, part of utils-linux(-ng)
yes, ipcs show the system v message queues but not the posix message queues.
if you mount the mqueue to the filesystem, you can see.
mkdir /dev/mqueue
mount -t mqueue none /dev/mqueue
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Hi,
I am working closly with unix message queues i have encountered the following -
after creating the Q and start working with it (pushing & pulling) i receive the following stange parameters on the q's -
STIME=no_entry
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Hi there:
Thanks first. When I use a message queue amony severl processes, will I have to synchronize the queue? I don't think I would have to because a message queue is implemented in a link listed. Correct me If I am wrong... (0 Replies)
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hi all,
I'm working on this problem for 2 days. Can somebody tell me that how to delete all message queues from the system ?
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I am sending and retriving the message to the queue
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hi all...
ive been trying this program where i spawn 4 threads... and i am trying to use message queue to send msgs from 3 of the threads to the parent thread... but it doent seem to be working... ive almost pulled out my hair tryin to fix the prob :confused:
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Hello,
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Hii can anyone pls tell how to limit the max no of message in a posix message queue. I have made changes in proc/sys/fs/mqueue/msg_max
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Hi all,
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Hello !!!!! I have a simple question but i can't find the answer anywhere hope to meet it here.
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LEARN ABOUT FREEBSD
mqueuefs
MQUEUEFS(5) BSD File Formats Manual MQUEUEFS(5)
NAME
mqueuefs -- POSIX message queue file system
SYNOPSIS
To link into kernel:
options P1003_1B_MQUEUE
To load as a kernel loadable module:
kldload mqueuefs
DESCRIPTION
The mqueuefs module will permit the FreeBSD kernel to support POSIX message queue. The module contains system calls to manipulate POSIX mes-
sage queues. It also contains a file system to implement a view for all message queues of the system. This helps users to keep track of
their message queues and make it more easily usable without having to invent additional tools.
The most common usage is as follows:
mount -t mqueuefs null /mnt/mqueue
where /mnt/mqueue is a mount point.
It is possible to define an entry in /etc/fstab that looks similar to:
null /mnt/mqueue mqueuefs rw 0 0
This will mount mqueuefs at the /mnt/mqueue mount point during system boot. Using /mnt/mqueue as a permanent mount point is not advised as
its intention has always been to be a temporary mount point. See hier(7) for more information on FreeBSD directory layout.
Some common tools can be used on the file system, e.g.: cat(1), chmod(1), chown(8), ls(1), rm(1), etc. To use only the message queue system
calls, it is not necessary for user to mount the file system, just load the module or compile it into the kernel. Manually creating a file,
for example, ``touch /mnt/mqueue/myqueue'', will create a message queue named myqueue in the kernel, default message queue attributes will be
applied to the queue. It is not advised to use this method to create a queue; it is better to use the mq_open(2) system call to create a
queue as it allows the user to specify different attributes.
To see the queue's attributes, just read the file:
cat /mnt/mqueue/myqueue
SEE ALSO
mq_open(2), nmount(2), unmount(2), mount(8), umount(8)
AUTHORS
This manual page was written by David Xu <davidxu@FreeBSD.org>.
BSD
November 30, 2005 BSD