<html lang="en">
<head>
<title>Memory Usage - Untitled</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="Untitled">
<meta name="generator" content="makeinfo 4.13">
<link title="Top" rel="start" href="index.html#Top">
<link rel="up" href="BFD-front-end.html#BFD-front-end" title="BFD front end">
<link rel="prev" href="Miscellaneous.html#Miscellaneous" title="Miscellaneous">
<link rel="next" href="Initialization.html#Initialization" title="Initialization">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<!--
This file documents the BFD library.
Copyright (C) 1991-2015 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being ``GNU General Public License'' and ``Funding
Free Software'', the Front-Cover texts being (a) (see below), and with
the Back-Cover Texts being (b) (see below). A copy of the license is
included in the section entitled ``GNU Free Documentation License''.
(a) The FSF's Front-Cover Text is:
A GNU Manual
(b) The FSF's Back-Cover Text is:
You have freedom to copy and modify this GNU Manual, like GNU
software. Copies published by the Free Software Foundation raise
funds for GNU development.-->
<meta http-equiv="Content-Style-Type" content="text/css">
<style type="text/css"><!--
pre.display { font-family:inherit }
pre.format { font-family:inherit }
pre.smalldisplay { font-family:inherit; font-size:smaller }
pre.smallformat { font-family:inherit; font-size:smaller }
pre.smallexample { font-size:smaller }
pre.smalllisp { font-size:smaller }
span.sc { font-variant:small-caps }
span.roman { font-family:serif; font-weight:normal; }
span.sansserif { font-family:sans-serif; font-weight:normal; }
--></style>
</head>
<body>
<div class="node">
<a name="Memory-Usage"></a>
<p>
Next: <a rel="next" accesskey="n" href="Initialization.html#Initialization">Initialization</a>,
Previous: <a rel="previous" accesskey="p" href="Miscellaneous.html#Miscellaneous">Miscellaneous</a>,
Up: <a rel="up" accesskey="u" href="BFD-front-end.html#BFD-front-end">BFD front end</a>
<hr>
</div>
<h3 class="section">2.4 Memory Usage</h3>
<p>BFD keeps all of its internal structures in obstacks. There is one obstack
per open BFD file, into which the current state is stored. When a BFD is
closed, the obstack is deleted, and so everything which has been
allocated by BFD for the closing file is thrown away.
<p>BFD does not free anything created by an application, but pointers into
<code>bfd</code> structures become invalid on a <code>bfd_close</code>; for example,
after a <code>bfd_close</code> the vector passed to
<code>bfd_canonicalize_symtab</code> is still around, since it has been
allocated by the application, but the data that it pointed to are
lost.
<p>The general rule is to not close a BFD until all operations dependent
upon data from the BFD have been completed, or all the data from within
the file has been copied. To help with the management of memory, there
is a function (<code>bfd_alloc_size</code>) which returns the number of bytes
in obstacks associated with the supplied BFD. This could be used to
select the greediest open BFD, close it to reclaim the memory, perform
some operation and reopen the BFD again, to get a fresh copy of the data
structures.
</body></html>