02-10-2012
POSIX Message Queue Memory Allocation
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 the queue is empty or full?
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LEARN ABOUT DEBIAN
nullmailer-queue
nullmailer-queue(8) System Manager's Manual nullmailer-queue(8)
NAME
nullmailer-queue - insert mail messages into the queue
SYNOPSIS
nullmailer-queue
DESCRIPTION
This program reads a formatted mail message from standard input and safely injects it into the outgoing mail queue.
The data sent into standard input is expected to have the following format: one line containing the envelope sender, one or more lines con-
taining the recipients, a single blank line, and then the contents of the message exactly as it is to be transmitted to the destination.
All lines are terminated with a single line-feed character. All addresses must contain a fully-qualified domain name.
RETURN VALUE
Exits 0 if it successfully queues the message. If it failed to queue the message, it exits 1 and prints an error message to stdandard out-
put.
CONTROL FILES
adminaddr
If this file is not empty, all recipients to users at either "localhost" (the literal string) or the canonical host name (from
/etc/mailname) are remapped to this address. This is provided to allow local daemons to be able to send email to "somebody@local-
host" and have it go somewhere sensible instead of being bounced by your relay host.
OTHER FILES
/var/spool/nullmailer/queue
The directory into which the completed messages are moved.
/var/spool/nullmailer/tmp
The directory in which messages are formed temporarily.
/var/spool/nullmailer/trigger
A pipe used to trigger nullmailer-send to immediately start sending the message from the queue.
SEE ALSO
nullmailer-inject(1), nullmailer-send(8)
LIMITATIONS
This program should enforce system-wide configurable message length limits.
nullmailer-queue(8)