<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <!--Converted with LaTeX2HTML 96.1-c (Feb 29, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds --> <HTML> <HEAD> <TITLE>IPC Identifiers</TITLE> <META NAME="description" CONTENT="IPC Identifiers"> <META NAME="keywords" CONTENT="lpg"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <LINK REL=STYLESHEET HREF="lpg.css"> </HEAD> <BODY LANG="EN"> <A NAME="tex2html663" HREF="node24.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="/icons//next_motif.gif"></A> <A NAME="tex2html661" HREF="node22.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="/icons//up_motif.gif"></A> <A NAME="tex2html655" HREF="node22.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="/icons//previous_motif.gif"></A> <A NAME="tex2html665" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="/icons//contents_motif.gif"></A> <BR> <B> Next:</B> <A NAME="tex2html664" HREF="node24.html">IPC Keys</A> <B>Up:</B> <A NAME="tex2html662" HREF="node22.html">6.4.1 Fundamental Concepts</A> <B> Previous:</B> <A NAME="tex2html656" HREF="node22.html">6.4.1 Fundamental Concepts</A> <BR> <P> <H3><A NAME="SECTION00741100000000000000">IPC Identifiers</A></H3> <P> Each IPC <EM>object</EM> has a unique IPC identifier associated with it. When we say ``IPC object'', we are speaking of a single message queue, semaphore set, or shared memory segment. This identifier is used within the kernel to uniquely identify an IPC object. For example, to access a particular shared memory segment, the only item you need is the unique ID value which has been assigned to that segment. <P> The uniqueness of an identifier is relevant to the <EM>type</EM> of object in question. To illustrate this, assume a numeric identifier of ``12345''. While there can never be two message queues with this same identifier, there exists the distinct possibility of a message queue and, say, a shared memory segment, which have the same numeric identifier. <P> <BR> <HR> <P><ADDRESS> <I>Converted on: <BR> Fri Mar 29 14:43:04 EST 1996</I> </ADDRESS> </BODY> </HTML>
