Hi All

My program failed while trying to open 10 diff message queues on a linux box. It was failing for the 10th message queue . Also i tried opening 5 msg queues each from 2 processes, but the tenth failed.

It looks like there is a limit specified somewhere on how many message queues that can be opened.

How do we solve this ? Where is it specified how many msgqueueus can be opened for per user or per system ?

Thanks
Raees

Hi there..
Yes there is a limit in aggregrate sizeof messages in bytes.
here is explaination in man page.

few lines in man msgctl:

Appropriate (probably, root) privileges are required to raise
the msg_qbytes value beyond the system parameter MSGMNB.

and few lines in man msgget:
msg_qbytes is set to the system limit MSGMNB.

The default value of MSGMNB is 16384 bytes.
usr/include/linux/msg.h:#define MSGMNB 16384 /* <= INT_MAX */ /* default max size of a message queue */


Perhaps I guess...
you are trying to send messages above MSGMNB limit.


-Kotrappa