message queues


 
Thread Tools Search this Thread
Top Forums UNIX for Advanced & Expert Users message queues
# 1  
Old 08-25-2008
message queues

#include <sys/ipc.h>
#include <sys/msg.h>

int main()
{
int qid;
int t;
struct msgbuf mesg;
qid=msgget(IPC_PRIVATE,IPC_CREAT);
mesg.mtype=1L;
mesg.mtext[0]=1;
t=msgsnd(qid,&mesg,1,0);
printf("%d",t);
}

the program prints -1 as the result of msgsnd ,which means that msgsnd doesn't work...any ideas??
# 2  
Old 08-25-2008
Print out errno too to why it doesn't work.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

Performance calculation for Message Queues

i have a program(C++ Code) that sends/receives information through queue's (Uses MQ) Is there any UNIX/LINUX tool that calculates the load and performance time for the same. If not how do i design the program that calculates the performance time. i know that time.h can be used but it gives... (2 Replies)
Discussion started by: vkca
2 Replies

2. Shell Programming and Scripting

Cleaning Message Queues

i have an application installed on AIX 5.3 and i have made a script that shutdown a proccesses that exceeded 10000kb of memory usage but i have a problem with cleaning the message queues of these proccesses after shutting them down. Is there any way to clean the message queues for this particular... (8 Replies)
Discussion started by: Portabello
8 Replies

3. Programming

Persisting message queues to disk

Hi, I have searched the forums and could not find a relavant thread discussing my use case, hence the new post. Basically am trying to pass on work to dummy worker instances from controller which will pass on work to workers (client) To make use of host capacity, am planning to serialize... (2 Replies)
Discussion started by: matrixmadhan
2 Replies

4. UNIX for Dummies Questions & Answers

message queues

can any body provide a tutorial that explains the concept of message queues in UNIX in great detail (1 Reply)
Discussion started by: asalman.qazi
1 Replies

5. UNIX for Advanced & Expert Users

UNIX Message Queues vs. Sockets

If I use sockets for IPC, and can easily distribute my applications. UNIX Message Queues are local to the processor. As I understand it, Message Queues still incur system call overhead, just like socket calls. What advantage does a UNIX Message Queue provide versus a TCP or UDP Socket,... (2 Replies)
Discussion started by: zen29sky
2 Replies

6. Programming

shared memory and message queues

Hi, According to my understanding.. When message queues are used, when a process post a message in the queue and if another process reads it from the queue then the queue will be empty unlike shared memory where n number of processess can access the shared memory and still the contents remain... (2 Replies)
Discussion started by: rvan
2 Replies

7. Linux

maximun number of message queues

how to check the maximun number of message queues in current linux enviornment? is there any command ? (4 Replies)
Discussion started by: princelinux
4 Replies

8. Solaris

rogue message queues solaris 9

We have message queues created from our ERP system to our tax system via an application api written by the ERP software vendor. Occasionally when a user does not gracefully exit the ERP application, the message queue hangs. After a few months, this becomes a problem as the queues are all used... (2 Replies)
Discussion started by: MizzGail
2 Replies

9. UNIX for Dummies Questions & Answers

message queues

let 3 processes a, b and c are sharing msgs using msg queues.process 'a' sending msg to 'c' and in turn 'c' send sthat msg to 'b'.if something happens to c how can 'a' and 'b' know that 'c' is not available?????? (2 Replies)
Discussion started by: sukaam
2 Replies

10. Programming

Message queues

Hi all, I've been trying for hours to figure out how to turn my 2-program (one to send and one to receive) "chat system" using message queues, into a single program where each concurrent component (entity) will both send and receive messages. PLEASE give me a hand with this, I'm starting to... (9 Replies)
Discussion started by: mgchato
9 Replies
Login or Register to Ask a Question