a message queue question..


 
Thread Tools Search this Thread
Top Forums Programming a message queue question..
# 1  
Old 03-30-2004
Question a message queue question..

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...
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Ubuntu

Message Queue in Linux

Hello How can I see the created message queues in the system? (4 Replies)
Discussion started by: xyzt
4 Replies

2. Programming

UNIX Message Queue

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

3. Programming

Message Queue Problem

Hi all, I need help about message queues, i have a server-client program that communicates each other via msg queue, firstly server opens its msg queue and waits for msg then client opens server msg queue and its own msg queue(for receiving msg from server,clients sends msg to server msg... (7 Replies)
Discussion started by: SaTYR
7 Replies

4. Programming

How to limit max no of message in a posix message queue

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

5. Programming

message queue

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

6. Programming

Message Queue with fork() help

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

7. IP Networking

message queue problem

I am sending and retriving the message to the queue the problem is after retrieving the message can i see what is there in my message queue. (actually in my application i am encountring some garbage value) so i want to retieve this garbage value and also want to know its size how... (0 Replies)
Discussion started by: ramneek
0 Replies

8. Programming

Message Queue Problem Again..

Is there any way one can delete , say , a particular message from a message queue on system V? (2 Replies)
Discussion started by: satansfury
2 Replies

9. Programming

Deleting ALL message queue

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 ? Since "ipcs -q" gives the list of all existing message queue, then there must be a system call and data stucture where from I can fetch the data about all existing... (2 Replies)
Discussion started by: v_rathor
2 Replies

10. UNIX for Advanced & Expert Users

Unix message Queue

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
Login or Register to Ask a Question
mq_unlink(3)						     Library Functions Manual						      mq_unlink(3)

NAME
mq_unlink - Removes a message queue (P1003.1b) LIBRARY
Realtime Library (librt.so, librt.a) SYNOPSIS
#include <mqueue.h> int mq_unlink ( const char *name); PARAMETERS
*name Specifies a pointer to the pathname of a message queue. DESCRIPTION
The mq_unlink function removes a message queue named by the pathname. After a successful call to this function, subsequent calls to the mq_open function fail if they specify the queue identified by the name argument and the O_CREAT flag is not set. Close the connection to the queue with a call to the mq_close function before calling the mq_unlink function. If one or more processes have the message queue open when mq_unlink is called, destruction of the queue is postponed until all references to the message queue are removed. In this situation, the mq_unlink function returns immediately, without waiting for all queue references to be closed. RETURN VALUES
On successful completion, the function returns the value 0 (zero); otherwise, the function returns the value -1, sets errno to indicate the error, and the message queue remains. ERRORS
The mq_unlink function fails under the following conditions: [EACCES] Permission is denied to unlink the message queue. [ENAMETOOLONG] The length of the name string exceeds {NAME_MAX} while {_POSIX_NO_TRUNC} is in effect. [ENOENT] The named message queue does not exist. Additionally, any error that can be returned by the open or fstat file system calls can be returned by the mq_unlink function. RELATED INFORMATION
Functions: mq_close(3), mq_open(3) Guide to Realtime Programming delim off mq_unlink(3)