|
|
|
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
|
|
|
|
|
|
|
|
|
|
<!--Converted with LaTeX2HTML 2008 (1.71)
|
|
|
|
|
original version by: Nikos Drakos, CBLU, University of Leeds
|
|
|
|
|
* revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan
|
|
|
|
|
* with significant contributions from:
|
|
|
|
|
Jens Lippmann, Marek Rouchal, Martin Wilck and others -->
|
|
|
|
|
<HTML>
|
|
|
|
|
<HEAD>
|
|
|
|
|
<TITLE>Descriptor data structure</TITLE>
|
|
|
|
|
<META NAME="description" CONTENT="Descriptor data structure">
|
|
|
|
|
<META NAME="keywords" CONTENT="userhtml">
|
|
|
|
|
<META NAME="resource-type" CONTENT="document">
|
|
|
|
|
<META NAME="distribution" CONTENT="global">
|
|
|
|
|
|
|
|
|
|
<META NAME="Generator" CONTENT="LaTeX2HTML v2008">
|
|
|
|
|
<META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css">
|
|
|
|
|
|
|
|
|
|
<LINK REL="STYLESHEET" HREF="userhtml.css">
|
|
|
|
|
|
|
|
|
|
<LINK REL="next" HREF="node16.html">
|
|
|
|
|
<LINK REL="previous" HREF="node9.html">
|
|
|
|
|
<LINK REL="up" HREF="node9.html">
|
|
|
|
|
<LINK REL="next" HREF="node11.html">
|
|
|
|
|
</HEAD>
|
|
|
|
|
|
|
|
|
|
<BODY >
|
|
|
|
|
<!--Navigation Panel-->
|
|
|
|
|
<A NAME="tex2html320"
|
|
|
|
|
HREF="node11.html">
|
|
|
|
|
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A>
|
|
|
|
|
<A NAME="tex2html316"
|
|
|
|
|
HREF="node9.html">
|
|
|
|
|
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A>
|
|
|
|
|
<A NAME="tex2html310"
|
|
|
|
|
HREF="node9.html">
|
|
|
|
|
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A>
|
|
|
|
|
<A NAME="tex2html318"
|
|
|
|
|
HREF="node1.html">
|
|
|
|
|
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A>
|
|
|
|
|
<BR>
|
|
|
|
|
<B> Next:</B> <A NAME="tex2html321"
|
|
|
|
|
HREF="node11.html">Methods</A>
|
|
|
|
|
<B> Up:</B> <A NAME="tex2html317"
|
|
|
|
|
HREF="node9.html">Data Structures and Classes</A>
|
|
|
|
|
<B> Previous:</B> <A NAME="tex2html311"
|
|
|
|
|
HREF="node9.html">Data Structures and Classes</A>
|
|
|
|
|
<B> <A NAME="tex2html319"
|
|
|
|
|
HREF="node1.html">Contents</A></B>
|
|
|
|
|
<BR>
|
|
|
|
|
<BR>
|
|
|
|
|
<!--End of Navigation Panel-->
|
|
|
|
|
|
|
|
|
|
<H2><A NAME="SECTION00041000000000000000"></A>
|
|
|
|
|
<A NAME="sec:desc"></A>
|
|
|
|
|
<BR>
|
|
|
|
|
Descriptor data structure
|
|
|
|
|
</H2>
|
|
|
|
|
All the general matrix informations and elements to be
|
|
|
|
|
exchanged among processes are stored within a data structure of the
|
|
|
|
|
type descdata<TT>psb_desc_type</TT>.
|
|
|
|
|
Every structure of this type is associated with a discretization
|
|
|
|
|
pattern and enables data communications and other operations that are
|
|
|
|
|
necessary for implementing the various algorithms of interest to us.
|
|
|
|
|
|
|
|
|
|
<P>
|
|
|
|
|
The data structure itself <code>psb_desc_type</code> can be treated as an
|
|
|
|
|
opaque object handled via the tools routines of
|
|
|
|
|
Sec. <A HREF="node56.html#sec:toolsrout">6</A> or the query routines detailed below;
|
|
|
|
|
nevertheless we include here a description for the curious
|
|
|
|
|
reader.
|
|
|
|
|
|
|
|
|
|
<P>
|
|
|
|
|
First we describe the <code>psb_indx_map</code> type. This is a data
|
|
|
|
|
structure that keeps track of a certain number of basic issues such
|
|
|
|
|
as:
|
|
|
|
|
|
|
|
|
|
<UL>
|
|
|
|
|
<LI>The value of the communication/MPI context;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>The number of indices in the index space, i.e. global number of
|
|
|
|
|
rows and columns of a sparse matrix;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>The local set of indices, including:
|
|
|
|
|
|
|
|
|
|
<UL>
|
|
|
|
|
<LI>The number of local indices (and local rows);
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>The number of halo indices (and therefore local columns);
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>The global indices corresponding to the local ones.
|
|
|
|
|
</LI>
|
|
|
|
|
</UL>
|
|
|
|
|
</LI>
|
|
|
|
|
</UL>
|
|
|
|
|
There are many different schemes for storing these data; therefore
|
|
|
|
|
there are a number of types extending the base one, and the descriptor
|
|
|
|
|
structure holds a polymorphic object whose dynamic type can be any of
|
|
|
|
|
the extended types.
|
|
|
|
|
The methods associated with this data type answer the following
|
|
|
|
|
queries:
|
|
|
|
|
|
|
|
|
|
<UL>
|
|
|
|
|
<LI>For a given set of local indices, find the corresponding indices
|
|
|
|
|
in the global numbering;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>For a given set of global indices, find the corresponding
|
|
|
|
|
indices in the local numbering, if any, or return an invalid
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>Add a global index to the set of halo indices;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>Find the process owner of each member of a set of global
|
|
|
|
|
indices.
|
|
|
|
|
</LI>
|
|
|
|
|
</UL>
|
|
|
|
|
All methods but the last are purely local; the last method potentially
|
|
|
|
|
requires communication among processes, and thus is a synchronous
|
|
|
|
|
method. The choice of a specific dynamic type for the index map is
|
|
|
|
|
made at the time the descriptor is initially allocated, according to
|
|
|
|
|
the mode of initialization (see also <A HREF="node56.html#sec:toolsrout">6</A>).
|
|
|
|
|
|
|
|
|
|
<P>
|
|
|
|
|
The descriptor contents are as follows:
|
|
|
|
|
<DL>
|
|
|
|
|
<DT><STRONG><B>indxmap</B></STRONG></DT>
|
|
|
|
|
<DD>A polymorphic variable of a type that is any
|
|
|
|
|
extension of the indx_map type described above.
|
|
|
|
|
<BR></DD>
|
|
|
|
|
<DT><STRONG><B>halo_index</B></STRONG></DT>
|
|
|
|
|
<DD>A list of the halo and boundary elements for
|
|
|
|
|
the current process to be exchanged with other processes; for each
|
|
|
|
|
processes with which it is necessary to communicate:
|
|
|
|
|
|
|
|
|
|
<OL>
|
|
|
|
|
<LI>Process identifier;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>Number of points to be received;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>Indices of points to be received;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>Number of points to be sent;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>Indices of points to be sent;
|
|
|
|
|
</LI>
|
|
|
|
|
</OL>
|
|
|
|
|
The list may contain an arbitrary number of groups; its end is marked
|
|
|
|
|
by a -1.
|
|
|
|
|
<BR>
|
|
|
|
|
Specified as: an allocatable integer array of rank one.
|
|
|
|
|
</DD>
|
|
|
|
|
<DT><STRONG><B>ext_index</B></STRONG></DT>
|
|
|
|
|
<DD>A list of element indices to be exchanged to
|
|
|
|
|
implement the mapping between a base descriptor and a descriptor
|
|
|
|
|
with overlap.
|
|
|
|
|
</DD>
|
|
|
|
|
<DT><STRONG><B>ovrlap_index</B></STRONG></DT>
|
|
|
|
|
<DD>A list of the overlap elements for the
|
|
|
|
|
current process, organized in groups like the previous vector:
|
|
|
|
|
|
|
|
|
|
<OL>
|
|
|
|
|
<LI>Process identifier;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>Number of points to be received;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>Indices of points to be received;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>Number of points to be sent;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>Indices of points to be sent;
|
|
|
|
|
</LI>
|
|
|
|
|
</OL>
|
|
|
|
|
The list may contain an arbitrary number of groups; its end is marked
|
|
|
|
|
by a -1.
|
|
|
|
|
<BR>
|
|
|
|
|
Specified as: an allocatable integer array of rank one.
|
|
|
|
|
</DD>
|
|
|
|
|
<DT><STRONG><B>ovr_mst_idx</B></STRONG></DT>
|
|
|
|
|
<DD>A list to retrieve the value of each
|
|
|
|
|
overlap element from the respective master process.
|
|
|
|
|
<BR>
|
|
|
|
|
Specified as: an allocatable integer array of rank one.
|
|
|
|
|
</DD>
|
|
|
|
|
<DT><STRONG><B>ovrlap_elem</B></STRONG></DT>
|
|
|
|
|
<DD>For all overlap points belonging to th
|
|
|
|
|
ecurrent process:
|
|
|
|
|
|
|
|
|
|
<OL>
|
|
|
|
|
<LI>Overlap point index;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>Number of processes sharing that overlap points;
|
|
|
|
|
</LI>
|
|
|
|
|
<LI>Index of a ``master'' process:
|
|
|
|
|
</LI>
|
|
|
|
|
</OL>
|
|
|
|
|
Specified as: an allocatable integer array of rank two.
|
|
|
|
|
</DD>
|
|
|
|
|
<DT><STRONG><B>bnd_elem</B></STRONG></DT>
|
|
|
|
|
<DD>A list of all boundary points, i.e. points
|
|
|
|
|
that have a connection with other processes.
|
|
|
|
|
</DD>
|
|
|
|
|
</DL>
|
|
|
|
|
The Fortran 2003 declaration for <code>psb_desc_type</code> structures is
|
|
|
|
|
as follows:
|
|
|
|
|
|
|
|
|
|
<DIV ALIGN="CENTER"><A NAME="fig:desctype"></A><A NAME="725"></A>
|
|
|
|
|
<TABLE>
|
|
|
|
|
<CAPTION ALIGN="BOTTOM"><STRONG>Figure 3:</STRONG>
|
|
|
|
|
The PSBLAS defined data type that
|
|
|
|
|
contains the communication descriptor.</CAPTION>
|
|
|
|
|
<TR><TD><DIV ALIGN="CENTER">
|
|
|
|
|
</DIV><TABLE WIDTH="90%">
|
|
|
|
|
<TR><TD>
|
|
|
|
|
<PRE>
|
|
|
|
|
type psb_desc_type
|
|
|
|
|
class(psb_indx_map), allocatable :: indxmap
|
|
|
|
|
integer, allocatable :: halo_index(:)
|
|
|
|
|
integer, allocatable :: ext_index(:)
|
|
|
|
|
integer, allocatable :: ovrlap_index(:)
|
|
|
|
|
integer, allocatable :: ovrlap_elem(:,:)
|
|
|
|
|
integer, allocatable :: ovr_mst_idx(:)
|
|
|
|
|
integer, allocatable :: bnd_elem(:)
|
|
|
|
|
end type psb_desc_type
|
|
|
|
|
</PRE></TD></TR>
|
|
|
|
|
</TABLE>
|
|
|
|
|
<DIV ALIGN="CENTER">
|
|
|
|
|
</DIV></TD></TR>
|
|
|
|
|
</TABLE>
|
|
|
|
|
</DIV>
|
|
|
|
|
|
|
|
|
|
<P>
|
|
|
|
|
A communication descriptor associated with a sparse matrix has a
|
|
|
|
|
state, which can take the following values:
|
|
|
|
|
<DL>
|
|
|
|
|
<DT><STRONG>Build:</STRONG></DT>
|
|
|
|
|
<DD>State entered after the first allocation, and before the
|
|
|
|
|
first assembly; in this state it is possible to add communication
|
|
|
|
|
requirements among different processes.
|
|
|
|
|
</DD>
|
|
|
|
|
<DT><STRONG>Assembled:</STRONG></DT>
|
|
|
|
|
<DD>State entered after the assembly; computations using
|
|
|
|
|
the associated sparse matrix, such as matrix-vector products, are
|
|
|
|
|
only possible in this state.
|
|
|
|
|
</DD>
|
|
|
|
|
</DL>
|
|
|
|
|
|
|
|
|
|
<P>
|
|
|
|
|
<BR><HR>
|
|
|
|
|
<!--Table of Child-Links-->
|
|
|
|
|
<A NAME="CHILD_LINKS"><STRONG>Subsections</STRONG></A>
|
|
|
|
|
|
|
|
|
|
<UL>
|
|
|
|
|
<LI><A NAME="tex2html322"
|
|
|
|
|
HREF="node11.html">Methods</A>
|
|
|
|
|
<LI><A NAME="tex2html323"
|
|
|
|
|
HREF="node12.html">get_local_rows -- Get number of local rows</A>
|
|
|
|
|
<LI><A NAME="tex2html324"
|
|
|
|
|
HREF="node13.html">get_local_cols -- Get number of local cols</A>
|
|
|
|
|
<LI><A NAME="tex2html325"
|
|
|
|
|
HREF="node14.html">get_global_rows -- Get number of global rows</A>
|
|
|
|
|
<LI><A NAME="tex2html326"
|
|
|
|
|
HREF="node15.html">get_global_cols -- Get number of global cols</A>
|
|
|
|
|
</UL>
|
|
|
|
|
<!--End of Table of Child-Links-->
|
|
|
|
|
<HR>
|
|
|
|
|
<!--Navigation Panel-->
|
|
|
|
|
<A NAME="tex2html320"
|
|
|
|
|
HREF="node11.html">
|
|
|
|
|
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A>
|
|
|
|
|
<A NAME="tex2html316"
|
|
|
|
|
HREF="node9.html">
|
|
|
|
|
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A>
|
|
|
|
|
<A NAME="tex2html310"
|
|
|
|
|
HREF="node9.html">
|
|
|
|
|
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A>
|
|
|
|
|
<A NAME="tex2html318"
|
|
|
|
|
HREF="node1.html">
|
|
|
|
|
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A>
|
|
|
|
|
<BR>
|
|
|
|
|
<B> Next:</B> <A NAME="tex2html321"
|
|
|
|
|
HREF="node11.html">Methods</A>
|
|
|
|
|
<B> Up:</B> <A NAME="tex2html317"
|
|
|
|
|
HREF="node9.html">Data Structures and Classes</A>
|
|
|
|
|
<B> Previous:</B> <A NAME="tex2html311"
|
|
|
|
|
HREF="node9.html">Data Structures and Classes</A>
|
|
|
|
|
<B> <A NAME="tex2html319"
|
|
|
|
|
HREF="node1.html">Contents</A></B>
|
|
|
|
|
<!--End of Navigation Panel-->
|
|
|
|
|
|
|
|
|
|
</BODY>
|
|
|
|
|
</HTML>
|
