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
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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)
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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)
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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)
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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
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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
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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)
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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)
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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)
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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
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imqdbmgr(1M) System Administration Commands imqdbmgr(1M)
NAME
imqdbmgr - manage a plugged-in JDBC-compliant Message Queue data store
SYNOPSIS
/usr/bin/imqdbmgr subcommand argument [ [option...]]
/usr/bin/imqdbmgr -h | -help
/usr/bin/imqdbmgr -v | -version
DESCRIPTION
The imqdbmgr utility creates and manages a Java DataBase Connectivity (JDBC) compliant database used for Message Queue persistent storage.
The database can be either embedded or external. To use a JDBC-compliant database (and the imdbmgr utility), you need to first set a number
of JDBC-related properties in the broker instance configuration file. See the Sun Java System Message Queue Administrator's Guide for addi-
tional information.
imqdbmgr supports four management subcommands. These subcommands, and their corresponding arguments and options follow the imqdbmgr command
on the command line. See USAGE and OPTIONS.
The following subcommands are supported:
create Create a Message Queue database schema.
delete Delete Message Queue database tables in the current data store.
recreate Delete Message Queue database tables and recreate Message Queue database schema in the curent data store.
reset Reset the database table lock to allow other processes to access database tables.
The imqdbmgr subcommands support the following arguments:
all Indicates the subcommand applies to the data store, as well as the database tables.
lck Indicates the subcommand applies to the database table lock.
oldtbl Indicates the subcommand applies to an older version of the database tables.
tbl Indicates the subcommand applies to the database tables only.
OPTIONS
The following options are supported:
-b brokerName Specify the broker instance name and corresponding instance configuration properties. If this option is not specified,
the default broker instance is assumed.
Use this option with the create, delete, recreate, or reset subcommands.
-D property=value Set system property property to value.
Use this option with the create, delete, recreate, or reset subcommands.
-h | -help Display usage help. Execute nothing else on the command line.
-p password Specify the database password.
Use this option with the create, delete, recreate, or reset subcommands.
-u userName Specify the database user name.
Use this option with the create, delete, recreate, or reset subcommands.
-v | -version Display version information. Execute nothing else on the command line.
USAGE
The following subcommands and associated arguments are supported:
create all
Create a new embedded data store and Message Queue database schema for a specified or default broker instance.
create tbl [-u userName] [-p password]
Create Message Queue database schema in an existing data store for a specified or default broker instance.
delete tbl [-u userName] [-p password]
Delete Message Queue database tables in the current data store for a specified or default broker instance.
delete oldtbl [-u userName] [-p password]
Delete the earlier version of Message Queue database tables. Used after the data store has been automatically migrated to the current
version of Message Queue.
recreate tbl [-u userName] [-p password]
Delete Message Queue database tables and recreate Message Queue database schema in the current data store for a specified or default
broker instance.
reset lck
Reset the database table lock to allow other processes to access database tables.
ENVIRONMENT VARIABLES
The following environment variables affect the execution of this command:
IMQ_JAVAHOME Specify the Java 2 compatible runtime. When this environment variable is not set it defaults to /usr/j2se.
EXIT STATUS
The following exit values are returned:
0 Successful completion.
>0 An error occurred.
FILES
/var/imq/instances/brokerName/dbstore
Recommended directory in which to create an embedded database.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWiqu |
+-----------------------------+-----------------------------+
SEE ALSO
imqadmin(1M), imqbrokerd(1M), imqcmd(1M), imqusermgr(1M), imqkeytool(1M), imqobjmgr(1M), attributes(5)
Sun Java System Message Queue Administrator's Guide
SunOS 5.11 29 Mar 2004 imqdbmgr(1M)