9 More Discussions You Might Find Interesting
1. Programming
I have a problem understanding the different scheduling queues (Ready Queue, I/O Queue, Job Queue) Can you please explain/illustrate/differentiate these queues to me? Thanks a lot guys.;) (1 Reply)
Discussion started by: zel2zel
1 Replies
2. UNIX for Dummies Questions & Answers
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
3. UNIX for Advanced & Expert Users
#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=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... (1 Reply)
Discussion started by: tolkki
1 Replies
4. BSD
Hi! Everybody%)
I got a question like this: Does my FreeBSD5.1 support Posix queues.
Thanks! (7 Replies)
Discussion started by: kamazi
7 Replies
5. UNIX for Dummies Questions & Answers
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
6. Programming
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
7. Linux
RH 7.2
Are there any commands to check the print queue status? Something along the lines of AIX's "qchk"?
Thanks!! (2 Replies)
Discussion started by: jalburger
2 Replies
8. UNIX for Advanced & Expert Users
Hi,
I submit some processes throught an at queue with the cmd at -q queue.
I can easily check the waiting process with atq. But how can I check running processes within a specific queue ?
Thanks,
Stef (2 Replies)
Discussion started by: stef
2 Replies
9. UNIX for Dummies Questions & Answers
I have a print queue set up with the following options: remote, standard processing, Hostname=(A Windows 2000 Server), bsd print spooler. It takes about 1 minute to transfer a 100 kb file and it times out (downs the queue) on larger files. When tested on a different system at a different location... (2 Replies)
Discussion started by: Scottb7711
2 Replies
MQ_CLOSE(2) BSD System Calls Manual MQ_CLOSE(2)
NAME
mq_close -- close a message queue (REALTIME)
LIBRARY
POSIX Real-time Library (librt, -lrt)
SYNOPSIS
#include <mqueue.h>
int
mq_close(mqd_t mqdes);
DESCRIPTION
The mq_close() system call removes the association between the message queue descriptor, mqdes, and its message queue. The results of using
this message queue descriptor after successful return from this mq_close(), and until the return of this message queue descriptor from a sub-
sequent mq_open(), are undefined.
If the process has successfully attached a notification request to the message queue via this mqdes, this attachment will be removed, and the
message queue is available for another process to attach for notification.
RETURN VALUES
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the
error.
ERRORS
The mq_close() system call will fail if:
[EBADF] The mqdes argument is not a valid message queue descriptor.
SEE ALSO
mq_open(2), mq_unlink(2)
STANDARDS
The mq_close() system call conforms to IEEE Std 1003.1-2004 (``POSIX.1'').
HISTORY
Support for POSIX message queues first appeared in FreeBSD 7.0.
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Elec-
trical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The
Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html.
BSD
November 29, 2005 BSD