<!-------- @HEADER ! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ! ! Zoltan Toolkit for Load-balancing, Partitioning, Ordering and Coloring ! Copyright 2012 Sandia Corporation ! ! Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation, ! the U.S. Government retains certain rights in this software. ! ! Redistribution and use in source and binary forms, with or without ! modification, are permitted provided that the following conditions are ! met: ! ! 1. Redistributions of source code must retain the above copyright ! notice, this list of conditions and the following disclaimer. ! ! 2. Redistributions in binary form must reproduce the above copyright ! notice, this list of conditions and the following disclaimer in the ! documentation and/or other materials provided with the distribution. ! ! 3. Neither the name of the Corporation nor the names of the ! contributors may be used to endorse or promote products derived from ! this software without specific prior written permission. ! ! THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY ! EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE ! IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR ! PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE ! CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, ! EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, ! PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR ! PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF ! LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING ! NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS ! SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. ! ! Questions? Contact Karen Devine kddevin@sandia.gov ! Erik Boman egboman@sandia.gov ! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ! ! @HEADER -------> <!doctype html public "-//w3c//dtd html 4.0 transitional//en"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <meta name="GENERATOR" content="Mozilla/4.7 [en] (X11; U; SunOS 5.7 sun4u) [Netscape]"> <meta name="sandia.approved" content="SAND99-1376"> <meta name="author" content="karen devine, kddevin@sandia.gov"> <title> Zoltan Developer's Guide: Adding Algorithms: How to handle memory</title> </head> <body bgcolor="#FFFFFF"> <div align=right><b><i><a href="dev.html">Zoltan Developer's Guide</a> | <a href="dev_add_params.html">Next</a> | <a href="dev_add_struct.html">Previous</a></i></b></div> <!-------------------------------------------------------------------------> <h2> Memory Management in Zoltan Algorithms</h2> Zoltan uses a <a href="../ug_html/ug_util_mem.html">memory management package</a> to simplify debugging of memory problems. It is strongly recommended that algorithm developers use the routines in this package, such as <a href="../ug_html/ug_util_mem.html#Zoltan_Malloc"><b>ZOLTAN_MALLOC</b> </a>, <a href="../ug_html/ug_util_mem.html#Zoltan_Calloc"><b>ZOLTAN_CALLOC</b> </a> and <b><a href="../ug_html/ug_util_mem.html#Zoltan_Free">ZOLTAN_FREE</a></b>, instead of the standard C routines for most memory management. <p> Macros that simplify the <a href="dev_lb_types.html#ID alloc">allocation of global and local identifiers (IDs)</a> are defined in <i>zz/zz_id_const.h</i>. These macros are described in the <a href="dev_lb_types.html">ID Data Types</a> section. The macros include error checking for the allocations and, thus, their use is highly recommended. <p>When a dynamic structure needs to be returned to the application, special memory allocation routines are needed. For example, the import and export lists of data to migrate are returned to an application from <b><a href="../ug_html/ug_interface_lb.html#Zoltan_LB_Partition">Zoltan_LB_Partition</a></b> and <b><a href="../ug_html/ug_interface_mig.html#Zoltan_Invert_Lists">Zoltan_Invert_Lists</a></b>. There are two special routines for managing memory for such situations, called <b><a href="#Zoltan_Special_Malloc">Zoltan_Special_Malloc</a></b> and <b><a href="#Zoltan_Special_Free">Zoltan_Special_Free</a></b>. Algorithms must use these functions to maintain compatibility with both C and Fortran90 applications; these special routines manage memory in a way that is compatible with both languages. <p>Some load-balancing algorithms may contain persistent data structures, that is, data structures that are preserved between calls to the load-balancing routine. The <a href="dev_lb_structs.html"><b>Zoltan_Struct</b></a> structure contains a field <a href="dev_add_struct.html"><i>LB.Data_Structure</i></a> for this purpose, allowing multiple Zoltan structures to preserve their own decomposition data. The developer should write a function that frees this data structure. Use <b>Zoltan_RCB_Free_Structure </b>as an example. <p> <!-------------------------------------------------------------------------> <hr> <a NAME="Zoltan_Special_Malloc"></a> <hr> int <b>Zoltan_Special_Malloc</b>(struct <b><a href="dev_lb_structs.html#Zoltan_Struct">Zoltan_Struct</a></b> *<i>zz</i>, void **<i>array</i>, int <i>size</i>, <b>ZOLTAN_SPECIAL_MALLOC_TYPE</b><i>type</i>); <hr> <p>The <b>Zoltan_Special_Malloc</b> routine allocates memory to be returned to the application by Zoltan (e.g., the result arrays of <b><a href="../ug_html/ug_interface_lb.html#Zoltan_LB_Partition">Zoltan_LB_Partition</a></b> and <b><a href="../ug_html/ug_interface_mig.html#Zoltan_Invert_Lists">Zoltan_Invert_Lists</a></b>). Returned memory must be allocated by <b>Zoltan_Special_Malloc</b> to insure it is allocated by the same language as the application. Memory allocated by <b>Zoltan_Special_Malloc</b> must be deallocated by <b><a href="#Zoltan_Special_Free">Zoltan_Special_Free</a></b>. <br> <table WIDTH="100%" > <tr VALIGN=TOP> <td VALIGN=TOP WIDTH="20%"><b>Arguments:</b></td> <td WIDTH="80%"></td> </tr> <tr> <td VALIGN=TOP><i> zz</i></td> <td>The Zoltan structure currently in use.</td> </tr> <tr> <td VALIGN=TOP><i> array</i></td> <td> Upon return, a pointer to the allocated space. Usually of type int** or <b><a href="dev_lb_types.html">ZOLTAN_ID_PTR</a></b>*. </td> </tr> <tr> <td VALIGN=TOP><i> size</i></td> <td>The number of elements (not bytes) to be allocated.</td> </tr> <tr> <td VALIGN=TOP> <i>type</i></td> <td>The type of array to allocate. Must be one of <b>ZOLTAN_SPECIAL_MALLOC_INT</b>, <b>ZOLTAN_SPECIAL_MALLOC_GID</b> or <b>ZOLTAN_SPECIAL_MALLOC_LID</b> for processor numbers, <a href="dev_lb_types.html">global IDs</a> and <a href="dev_lb_types.html">local IDs</a>, respectively. </td> </tr> <tr> <td><b>Returned Value:</b></td> <td></td> </tr> <tr> <td VALIGN=TOP> int</td> <td>1 if the allocation succeeded; 0 if it failed.</td> </tr> <tr> <td VALIGN=TOP><b>Example:</b></td> <td></td> </tr> <tr> <td VALIGN=TOP></td> <td> <tt> ierr = <b>Zoltan_Special_Malloc</b>(<i>zz</i>, (void **)<i>import_gid</i>, <br> <i>num_import</i>, <br> <b>ZOLTAN_SPECIAL_MALLOC_GID</b>); </tt> </td> </tr> <tr> <td VALIGN=TOP></td> <td>Allocates an array with <i>num_import</i> <a href="dev_lb_types.html">global IDs</a> and returns a pointer to the allocated space in <i>import_gid</i>. </td> </tr> </table> <p> <!-------------------------------------------------------------------------> <hr> <a NAME="Zoltan_Special_Free"></a> <hr> int <b>Zoltan_Special_Free</b>(struct <b><a href="dev_lb_structs.html#Zoltan_Struct">Zoltan_Struct</a></b> *<i>zz</i>, void **<i>array</i>,<b> ZOLTAN_SPECIAL_MALLOC_TYPE</b> <i>type</i>); <hr> <p><b>Zoltan_Special_Free</b> frees memory allocated by <b><a href="#Zoltan_Special_Malloc">Zoltan_Special_Malloc</a></b>. The array pointer is set to NULL upon return. <br> <table WIDTH="100%" > <tr VALIGN=TOP> <td VALIGN=TOP WIDTH="20%"><b>Arguments:</b></td> <td WIDTH="80%"></td> </tr> <tr> <td VALIGN=TOP><i> zz</i></td> <td>The Zoltan structure currently in use.</td> </tr> <tr> <td VALIGN=TOP><i> array</i></td> <td>The array to be freed. Upon return, the pointer is set to NULL.</td> </tr> <tr> <td VALIGN=TOP> <i>type</i></td> <td>The type of the array. Must be one of <b>ZOLTAN_SPECIAL_MALLOC_INT</b>, <b>ZOLTAN_SPECIAL_MALLOC_GID</b> or <b>ZOLTAN_SPECIAL_MALLOC_LID</b> for processor numbers, <a href="dev_lb_types.html">global IDs</a> and <a href="dev_lb_types.html">local IDs</a>, respectively.</td> </tr> <tr> <td><b>Returned Value:</b></td> <td></td> </tr> <tr> <td VALIGN=TOP> int</td> <td>1 if the deallocation succeeded; 0 if it failed.</td> </tr> <tr> <td VALIGN=TOP><b>Example:</b></td> <td></td> </tr> <tr> <td VALIGN=TOP></td> <td> <tt> ierr = <b>Zoltan_Special_Free</b>(<i>zz</i>, (void **)<i>import_gid</i>, <br> <b>ZOLTAN_SPECIAL_MALLOC_GID</b>); </tt> </td> </tr> <tr> <td VALIGN=TOP></td> <td>Frees the <b><a href="dev_lb_types.html">global IDs</a></b> array <i>import_gid</i> and sets it to NULL.</td> </tr> </table> <br> <p> <!-------------------------------------------------------------------------> <hr WIDTH="100%"> <br>[<a href="dev.html">Table of Contents</a> | <a href="dev_add_params.html">Next: Parameters</a> | <a href="dev_add_struct.html">Previous: Data Structures</a> | <a href="https://www.sandia.gov/general/privacy-security/index.html">Privacy and Security</a>] </body> </html>