10 More Discussions You Might Find Interesting
1. Programming
hello, I try to test the POSIX mq_open function on book unp like below:
#include "unpipc.h"
# include <mqueue.h>
int main(int argc, char **argv)
{
int c, flags;
mqd_t mqd;
flags = O_RDWR | O_CREAT;
while ((c = getopt(argc, argv, "e")) != -1) {
... (3 Replies)
Discussion started by: anpufeng
3 Replies
2. Programming
Hi,
I wanted to know whether the POSIX message queues are statically allocated memory by the kernel based on the parameters specified in the open or as and when we send messages, memory are allocated?
Does the kernel reserve the specified memory for the message queue irrespective of whether... (1 Reply)
Discussion started by: sumtata
1 Replies
3. 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
... (1 Reply)
Discussion started by: ouou
1 Replies
4. Programming
Hello,
I am trying to implement posix message queue application. I am faced with an error on the mq_receive section. It says "Message too long". I've tried couple of small tweeks, but to no result. Please do suggest any rectificaitons.
mq_send section-works successfully
#include... (2 Replies)
Discussion started by: katwalatapan
2 Replies
5. Programming
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... (2 Replies)
Discussion started by: qlyine
2 Replies
6. Programming
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.... (0 Replies)
Discussion started by: mohit3884
0 Replies
7. Linux
Hi all,
Please tell me how to change POSIX message queue maximum size? "ulimit" is not a solution because it controls shell resources. But i need to control queue size before login in and starting the shell. It is needed to limit queue size for applications started before login in.
Sorry for my... (7 Replies)
Discussion started by: Vourhey
7 Replies
8. Programming
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...
... (2 Replies)
Discussion started by: etenv
2 Replies
9. HP-UX
Hello,
My question is related to "pipcs -qa" command under HP-UX 11i PA-RISC 64 bits.
We have a little C program that creates posix ipc message queues using the mq_open() system function.
The program fail with 'No space left on device' error when we create big queues. What is the system... (6 Replies)
Discussion started by: cadanir
6 Replies
10. Programming
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... (0 Replies)
Discussion started by: yanhu
0 Replies
dlpi_max_ub_promisc(5) File Formats Manual dlpi_max_ub_promisc(5)
NAME
dlpi_max_ub_promisc - maximum number of unbound promiscuous streams allowed on a LAN interface
VALUES
Failsafe
Default
Allowed values
or
Recommended values
DESCRIPTION
The tunable is used to dynamically increase or decrease the maximum number of unbound promiscuous streams that can be opened on a LAN
interface.
Enabling multiple unbound promiscuous streams may cause CPU utilization to increase up to three times as compared to CPU utilization with
no unbound promiscuous streams. Increasing the value of this tunable does not by itself degrade networking or kernel performance.
Who Is Expected to Change This Tunable?
Privileged user.
Restrictions on Changing
Changes to this tunable take effect immediately. When value is reduced from a higher value to a lower value, the existing unbound promis-
cuous streams will not be stopped to accommodate the change. However, this tunable will limit the new unbound streams created on the
interface.
When Should the Value of This Tunable Be Raised?
This tunable should be raised when the number of unbound promiscuous applications needs to be more than the default value.
What Are the Side Effects of Raising the Value?
Side effect may be an increase in CPU utilization.
WARNINGS
All HP-UX kernel tunable parameters are release specific. This parameter may be removed or have its meaning changed in future releases of
HP-UX.
Installation of optional kernel software, from HP or other vendors, may cause changes to tunable parameter values. After installation,
some tunable parameters may no longer be at the default or recommended values. For information about the effects of installation on tun-
able values, consult the documentation for the kernel software being installed. For information about optional kernel software that was
factory installed on your system, see at
AUTHOR
was developed by HP.
SEE ALSO
kctune(1M), lanadmin(1M), gettune(2), settune(2), lan(7).
DLPI Programmer's Guide on
Tunable Kernel Parameters dlpi_max_ub_promisc(5)
