11-15-2010
Hi Loic,
I tried to write a simple program by just calling the mq_open method.. then also i am getting the same error. Thank you for your valuable time..Kindly help me to get out of this.. One thing I noticed is if i use a msgget() method to create a new message queue it is working fine.. can i use it in program.. can u pls tell me the difference between both.
regards,
paru.
10 More Discussions You Might Find Interesting
1. UNIX for Advanced & Expert Users
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
Qnum=0
CBYTES=4140
when this happens, the Q is disabled (meaning i... (3 Replies)
Discussion started by: kel
3 Replies
2. HP-UX
Hello,
J work on a HP.
I want to create message queue by using mq_open with this parameters:
mq_open(p,O_CREAT|O_WRONLY|O_EXCL|0_NONBLOCK,0600,&queue_attr)
with p char
and the function returns the value -1 and errno equal 2.
can you help me ?
Thank. (3 Replies)
Discussion started by: AUBERT
3 Replies
3. Programming
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:
another wierd thing... (1 Reply)
Discussion started by: strider
1 Replies
4. Programming
Hello,
i need to write a message queue "chat server", that should work only localy.
Can anyone please help me with some ideas and peshaps code. I'm studying the UNIX IPC mechanisms right now. So far, i understand how it works but i still cannot get an idea how to write a chat programm...
... (2 Replies)
Discussion started by: etenv
2 Replies
5. Programming
hello,
I had to implement a message queue application....between 30 processes......
all 30 proceses are getting data from serial port....
And here is THE FLOW::::::::1 connector process...which is linked with message queue to all the 30 applications. Processes get the data from serial port and... (9 Replies)
Discussion started by: arunchaudhary19
9 Replies
6. Programming
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
But still whenever i try to read the value of max. message in the queue using attr.mq_curmsgs (where struct mq_attr attr) its giving the default value as 10.... (0 Replies)
Discussion started by: mohit3884
0 Replies
7. Programming
Hello !!!!! I have a simple question but i can't find the answer anywhere hope to meet it here.
Why it is a bad idea to pass pointers through message queues ?
Most structs i see all of their char types are arrays... Is it becase having pointers means we could possibily send wrong bytes ?
For... (2 Replies)
Discussion started by: qlyine
2 Replies
8. Ubuntu
Hello
How can I see the created message queues in the system? (4 Replies)
Discussion started by: xyzt
4 Replies
9. Programming
Hi guys.
i have wrote a simple program to test message queue attributes. here it is:
#include <stdio.h>
#include <stdlib.h>
#include <mqueue.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <sys/stat.h>
int main()
{
struct mq_attr attr;
mqd_t mqd;
... (2 Replies)
Discussion started by: majid.merkava
2 Replies
10. Programming
hello, I try to test the POSIX mq_open function on book unp like below:
#include "unpipc.h"
# include <mqueue.h>
int main(int argc, char **argv)
{
int c, flags;
mqd_t mqd;
flags = O_RDWR | O_CREAT;
while ((c = getopt(argc, argv, "e")) != -1) {
... (3 Replies)
Discussion started by: anpufeng
3 Replies
LEARN ABOUT OPENSOLARIS
mq_unlink
mq_unlink(3C) Standard C Library Functions mq_unlink(3C)
NAME
mq_unlink - remove a message queue
SYNOPSIS
#include <mqueue.h>
int mq_unlink(const char *name);
DESCRIPTION
The mq_unlink() function removes the message queue named by the pathname name. After a successful call to mq_unlink() with name, a call to
mq_open(3C) with name fails if the flag O_CREAT is not set in flags. If one or more processes have the message queue open when mq_unlink()
is called, destruction of the message queue is postponed until all references to the message queue have been closed. Calls to mq_open(3C)
to re-create the message queue may fail until the message queue is actually removed. However, the mq_unlink() call need not block until all
references have been closed; it may return immediately.
RETURN VALUES
Upon successful completion, mq_unlink() returns 0; otherwise, the named message queue is not changed by this function call, the function
returns -1 and sets errno to indicate the error.
ERRORS
The mq_unlink() function will fail if:
EACCES Permission is denied to unlink the named message queue.
ENAMETOOLONG The length of the name string exceeds PATH_MAX, or a pathname component is longer than NAME_MAX while _POSIX_NO_TRUNC
is in effect.
ENOENT The named message queue, name, does not exist.
ENOSYS mq_unlink() is not supported by the system.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
|ATTRIBUTE TYPE |ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Committed |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
|Standard |See standards(5). |
+-----------------------------+-----------------------------+
SEE ALSO
mqueue.h(3HEAD), mq_close(3C), mq_open(3C), attributes(5), standards(5)
NOTES
Solaris 2.6 was the first release to support the Asynchronous Input and Output option. Prior to this release, this function always returned
-1 and set errno to ENOSYS.
SunOS 5.11 5 Feb 2008 mq_unlink(3C)