Unix message Queue Post: 38909

Sponsored Content

Top Forums UNIX for Advanced & Expert Users Unix message Queue Post 38909 by kel on Wednesday 30th of July 2003 08:42:51 AM

07-30-2003

Registered User

Hi,
Thanks for your replay.

I'll try to be more clear -
1. i have created the Q as follow:
'o_qid = msgget(IPC_PRIVATE,IPC_CREAT|0777|IPC_EXCL|S_IRUSR|S_IWUSR);'

And worked with the Q as follow:
'msgsnd( qid, (void*)(&eventDataBuffer), MessageSize, 0) '
'qbytesread=msgrcv(qid, (void*)pMessage, max_msgsize, -MSGTYPE_MAX_APP_RANGE, 0)'

2. The Q has functioned OK for about an hour, where data was surely sent & received.

3. On a certain point, i could not send, nor receive from the Q.
The parameters on the Q where:
Qnum=0 (The number of messages currently outstanding on the
associated message queue.)
CBYTES= ~4k (The number of bytes in messages currently outstanding on the associated message queue.)

This is what i do not understand. How come there are no messages, and the Q inform me that the data size is greater than 0?

I hope i made more clear.
Thanks Again.

kel

View Public Profile for kel

Find all posts by kel

10 More Discussions You Might Find Interesting

1. Programming

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...

2. 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...

3. Programming

Message Queue Problem Again..

Is there any way one can delete , say , a particular message from a message queue on system V?

4. 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...

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... ...

6. 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....

7. 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...

8. 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...

9. Shell Programming and Scripting

Move xml files from unix to message queue.

Hi, I need to move the XML files from the UNIX to the message queue. Please help me out to write the code.. Thanks, Mohana Krishnan

10. Programming

Please help:program hang stuck there signal handling on POSIX Message Queue UNIX C programming

in a single main() function,so need signal handling. Use Posix Message Queue IPC mechanism , can ignore the priority and other linked list message,to implement the scenario: client:Knock Knock server:who's there client: Eric Server:Eric,Welcome. client:exit all process terminated ...

LEARN ABOUT DEBIAN

queue.dequeue

Queue.dequeue(3kaya)					       Kaya module reference					      Queue.dequeue(3kaya)

NAME

       Queue::dequeue - Remove an item from a queue.

SYNOPSIS

       a dequeue( Queue<a>  q )

ARGUMENTS

       q The queue

DESCRIPTION

       Removes	the  front  item  from the queue, and returns the removed item. If the queue is empty, then the Queue.EmptyQueue(3kaya) exception
       will be thrown.

AUTHORS

       Kaya standard library by Edwin Brady, Chris Morris and others (kaya@kayalang.org). For further information see http://kayalang.org/

LICENSE

       The Kaya standard library is free software; you can redistribute it and/or modify it under the terms  of  the  GNU  Lesser  General  Public
       License (version 2.1 or any later version) as published by the Free Software Foundation.

RELATED

       Queue.array(3kaya)
       Queue.empty(3kaya)
       Queue.enqueue(3kaya)
       Queue.length(3kaya)

Kaya								   October 2012 					      Queue.dequeue(3kaya)

10 More Discussions You Might Find Interesting

1. Programming

a message queue question..

Discussion started by: yanhu

2. Programming

Deleting ALL message queue

Discussion started by: v_rathor

3. Programming

Message Queue Problem Again..

Discussion started by: satansfury

4. IP Networking

message queue problem

Discussion started by: ramneek