161 lines
6.7 KiB
HTML
161 lines
6.7 KiB
HTML
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<html>
|
||
|
|
<!-- This file documents the BFD library.
|
||
|
|
|
||
|
|
Copyright (C) 1991-2016 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. -->
|
||
|
|
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>Untitled Document: File Caching</title>
|
||
|
|
|
||
|
|
<meta name="description" content="Untitled Document: File Caching">
|
||
|
|
<meta name="keywords" content="Untitled Document: File Caching">
|
||
|
|
<meta name="resource-type" content="document">
|
||
|
|
<meta name="distribution" content="global">
|
||
|
|
<meta name="Generator" content="makeinfo">
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
||
|
|
<link href="index.html#Top" rel="start" title="Top">
|
||
|
|
<link href="BFD-Index.html#BFD-Index" rel="index" title="BFD Index">
|
||
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
||
|
|
<link href="BFD-front-end.html#BFD-front-end" rel="up" title="BFD front end">
|
||
|
|
<link href="Linker-Functions.html#Linker-Functions" rel="next" title="Linker Functions">
|
||
|
|
<link href="Internal.html#Internal" rel="prev" title="Internal">
|
||
|
|
<style type="text/css">
|
||
|
|
<!--
|
||
|
|
a.summary-letter {text-decoration: none}
|
||
|
|
blockquote.smallquotation {font-size: smaller}
|
||
|
|
div.display {margin-left: 3.2em}
|
||
|
|
div.example {margin-left: 3.2em}
|
||
|
|
div.indentedblock {margin-left: 3.2em}
|
||
|
|
div.lisp {margin-left: 3.2em}
|
||
|
|
div.smalldisplay {margin-left: 3.2em}
|
||
|
|
div.smallexample {margin-left: 3.2em}
|
||
|
|
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
|
||
|
|
div.smalllisp {margin-left: 3.2em}
|
||
|
|
kbd {font-style:oblique}
|
||
|
|
pre.display {font-family: inherit}
|
||
|
|
pre.format {font-family: inherit}
|
||
|
|
pre.menu-comment {font-family: serif}
|
||
|
|
pre.menu-preformatted {font-family: serif}
|
||
|
|
pre.smalldisplay {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smallexample {font-size: smaller}
|
||
|
|
pre.smallformat {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smalllisp {font-size: smaller}
|
||
|
|
span.nocodebreak {white-space:nowrap}
|
||
|
|
span.nolinebreak {white-space:nowrap}
|
||
|
|
span.roman {font-family:serif; font-weight:normal}
|
||
|
|
span.sansserif {font-family:sans-serif; font-weight:normal}
|
||
|
|
ul.no-bullet {list-style: none}
|
||
|
|
-->
|
||
|
|
</style>
|
||
|
|
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
|
||
|
|
<a name="File-Caching"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Linker-Functions.html#Linker-Functions" accesskey="n" rel="next">Linker Functions</a>, Previous: <a href="Internal.html#Internal" accesskey="p" rel="prev">Internal</a>, Up: <a href="BFD-front-end.html#BFD-front-end" accesskey="u" rel="up">BFD front end</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="BFD-Index.html#BFD-Index" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<a name="File-caching"></a>
|
||
|
|
<h3 class="section">2.16 File caching</h3>
|
||
|
|
<p>The file caching mechanism is embedded within BFD and allows
|
||
|
|
the application to open as many BFDs as it wants without
|
||
|
|
regard to the underlying operating system’s file descriptor
|
||
|
|
limit (often as low as 20 open files). The module in
|
||
|
|
<code>cache.c</code> maintains a least recently used list of
|
||
|
|
<code>bfd_cache_max_open</code> files, and exports the name
|
||
|
|
<code>bfd_cache_lookup</code>, which runs around and makes sure that
|
||
|
|
the required BFD is open. If not, then it chooses a file to
|
||
|
|
close, closes it and opens the one wanted, returning its file
|
||
|
|
handle.
|
||
|
|
</p>
|
||
|
|
<a name="Caching-functions"></a>
|
||
|
|
<h4 class="subsection">2.16.1 Caching functions</h4>
|
||
|
|
|
||
|
|
|
||
|
|
<a name="index-bfd_005fcache_005finit"></a>
|
||
|
|
<a name="bfd_005fcache_005finit"></a>
|
||
|
|
<h4 class="subsubsection">2.16.1.1 <code>bfd_cache_init</code></h4>
|
||
|
|
<p><strong>Synopsis</strong>
|
||
|
|
</p><div class="example">
|
||
|
|
<pre class="example">bfd_boolean bfd_cache_init (bfd *abfd);
|
||
|
|
</pre></div>
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
Add a newly opened BFD to the cache.
|
||
|
|
</p>
|
||
|
|
<a name="index-bfd_005fcache_005fclose"></a>
|
||
|
|
<a name="bfd_005fcache_005fclose"></a>
|
||
|
|
<h4 class="subsubsection">2.16.1.2 <code>bfd_cache_close</code></h4>
|
||
|
|
<p><strong>Synopsis</strong>
|
||
|
|
</p><div class="example">
|
||
|
|
<pre class="example">bfd_boolean bfd_cache_close (bfd *abfd);
|
||
|
|
</pre></div>
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
Remove the BFD <var>abfd</var> from the cache. If the attached file is open,
|
||
|
|
then close it too.
|
||
|
|
</p>
|
||
|
|
<p><strong>Returns</strong><br>
|
||
|
|
<code>FALSE</code> is returned if closing the file fails, <code>TRUE</code> is
|
||
|
|
returned if all is well.
|
||
|
|
</p>
|
||
|
|
<a name="index-bfd_005fcache_005fclose_005fall"></a>
|
||
|
|
<a name="bfd_005fcache_005fclose_005fall"></a>
|
||
|
|
<h4 class="subsubsection">2.16.1.3 <code>bfd_cache_close_all</code></h4>
|
||
|
|
<p><strong>Synopsis</strong>
|
||
|
|
</p><div class="example">
|
||
|
|
<pre class="example">bfd_boolean bfd_cache_close_all (void);
|
||
|
|
</pre></div>
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
Remove all BFDs from the cache. If the attached file is open,
|
||
|
|
then close it too.
|
||
|
|
</p>
|
||
|
|
<p><strong>Returns</strong><br>
|
||
|
|
<code>FALSE</code> is returned if closing one of the file fails, <code>TRUE</code> is
|
||
|
|
returned if all is well.
|
||
|
|
</p>
|
||
|
|
<a name="index-bfd_005fopen_005ffile"></a>
|
||
|
|
<a name="bfd_005fopen_005ffile"></a>
|
||
|
|
<h4 class="subsubsection">2.16.1.4 <code>bfd_open_file</code></h4>
|
||
|
|
<p><strong>Synopsis</strong>
|
||
|
|
</p><div class="example">
|
||
|
|
<pre class="example">FILE* bfd_open_file (bfd *abfd);
|
||
|
|
</pre></div>
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
Call the OS to open a file for <var>abfd</var>. Return the <code>FILE *</code>
|
||
|
|
(possibly <code>NULL</code>) that results from this operation. Set up the
|
||
|
|
BFD so that future accesses know the file is open. If the <code>FILE *</code>
|
||
|
|
returned is <code>NULL</code>, then it won’t have been put in the
|
||
|
|
cache, so it won’t have to be removed from it.
|
||
|
|
</p>
|
||
|
|
|
||
|
|
<hr>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Linker-Functions.html#Linker-Functions" accesskey="n" rel="next">Linker Functions</a>, Previous: <a href="Internal.html#Internal" accesskey="p" rel="prev">Internal</a>, Up: <a href="BFD-front-end.html#BFD-front-end" accesskey="u" rel="up">BFD front end</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="BFD-Index.html#BFD-Index" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|