mq_open error

mageshvan · 10-08-2007, 09:18 AM

Hi,

Am creating a msgqueue using mq_open
</code>
main()
{
struct mq_attr attr; /* message queue attributes structure */
memset(&_attr,0,sizeof(struct mq_attr));
attr.mq_maxmsg= 10;
attr.mq_msgsize= 20;

msg.flag = HS_FWK_MSGQ_FLAGS;
mq_open("/h_qname",O_CREAT|O_RDWR|O_EXCL|O_NONBLOCK, 00666,&attr);

then sending message using
mq_send(....)
}

Again opening the message queue using the name to receive the message...but mq_open fails here...
main()
{
struct mq_attr attr; /* message queue attributes structure */
memset(&_attr,0,sizeof(struct mq_attr));
attr.mq_maxmsg= 10;
attr.mq_msgsize= 20;

msg.flag = HS_FWK_MSGQ_FLAGS;
mq_open("h_qname",O_CREAT|O_RDONLY, 00666,&attr);

}
<code>

I tried with O_RDWR flag too... but thatz also failing... i couldn't find out where exactly am going wrong... could somebody help me on this.

Thanks.

orgcandman · 10-08-2007, 12:05 PM

Firstly, your queue in the second like does not have the required "/" precursor.

If it were me, I'd do the following:

For the process which will be reading the MQ:

Code:

mqid = mq_open ("/h_queue",
                O_CREAT | O_RDWR | O_EXCL | S_IRWXU | S_IRWXG | S_IRWXO,
                0, NULL);

For the process which will be sending the message to that queue:

Code:

mqid = mq_open("/hqueue", O_WRONLY, 0, NULL);

-Aaron