<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ --> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Function Locking (GNU Octave (version 5.1.0))</title> <meta name="description" content="Function Locking (GNU Octave (version 5.1.0))"> <meta name="keywords" content="Function Locking (GNU Octave (version 5.1.0))"> <meta name="resource-type" content="document"> <meta name="distribution" content="global"> <meta name="Generator" content="makeinfo"> <link href="index.html#Top" rel="start" title="Top"> <link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> <link href="Function-Files.html#Function-Files" rel="up" title="Function Files"> <link href="Function-Precedence.html#Function-Precedence" rel="next" title="Function Precedence"> <link href="Overloading-and-Autoloading.html#Overloading-and-Autoloading" rel="prev" title="Overloading and Autoloading"> <style type="text/css"> <!-- a.summary-letter {text-decoration: none} blockquote.indentedblock {margin-right: 0em} blockquote.smallindentedblock {margin-right: 0em; font-size: smaller} blockquote.smallquotation {font-size: smaller} div.display {margin-left: 3.2em} div.example {margin-left: 3.2em} div.lisp {margin-left: 3.2em} div.smalldisplay {margin-left: 3.2em} div.smallexample {margin-left: 3.2em} 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.nolinebreak {white-space: nowrap} span.roman {font-family: initial; font-weight: normal} span.sansserif {font-family: sans-serif; font-weight: normal} ul.no-bullet {list-style: none} --> </style> <link rel="stylesheet" type="text/css" href="octave.css"> </head> <body lang="en"> <a name="Function-Locking"></a> <div class="header"> <p> Next: <a href="Function-Precedence.html#Function-Precedence" accesskey="n" rel="next">Function Precedence</a>, Previous: <a href="Overloading-and-Autoloading.html#Overloading-and-Autoloading" accesskey="p" rel="prev">Overloading and Autoloading</a>, Up: <a href="Function-Files.html#Function-Files" accesskey="u" rel="up">Function Files</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> </div> <hr> <a name="Function-Locking-1"></a> <h4 class="subsection">11.9.6 Function Locking</h4> <p>It is sometime desirable to lock a function into memory with the <code>mlock</code> function. This is typically used for dynamically linked functions in oct-files or mex-files that contain some initialization, and it is desirable that calling <code>clear</code> does not remove this initialization. </p> <p>As an example, </p> <div class="example"> <pre class="example">function my_function () mlock (); … endfunction </pre></div> <p>prevents <code>my_function</code> from being removed from memory after it is called, even if <code>clear</code> is called. It is possible to determine if a function is locked into memory with the <code>mislocked</code>, and to unlock a function with <code>munlock</code>, which the following code illustrates. </p> <div class="example"> <pre class="example">my_function (); mislocked ("my_function") ⇒ ans = 1 munlock ("my_function"); mislocked ("my_function") ⇒ ans = 0 </pre></div> <p>A common use of <code>mlock</code> is to prevent persistent variables from being removed from memory, as the following example shows: </p> <div class="example"> <pre class="example">function count_calls () mlock (); persistent calls = 0; printf ("count_calls() has been called %d times\n", ++calls); endfunction count_calls (); -| count_calls() has been called 1 times clear count_calls count_calls (); -| count_calls() has been called 2 times </pre></div> <p><code>mlock</code> might also be used to prevent changes to an m-file, such as in an external editor, from having any effect in the current Octave session; A similar effect can be had with the <code>ignore_function_time_stamp</code> function. </p> <a name="XREFmlock"></a><dl> <dt><a name="index-mlock"></a><em></em> <strong>mlock</strong> <em>()</em></dt> <dd><p>Lock the current function into memory so that it can’t be removed with <code>clear</code>. </p> <p><strong>See also:</strong> <a href="#XREFmunlock">munlock</a>, <a href="#XREFmislocked">mislocked</a>, <a href="Persistent-Variables.html#XREFpersistent">persistent</a>, <a href="Status-of-Variables.html#XREFclear">clear</a>. </p></dd></dl> <a name="XREFmunlock"></a><dl> <dt><a name="index-munlock"></a><em></em> <strong>munlock</strong> <em>()</em></dt> <dt><a name="index-munlock-1"></a><em></em> <strong>munlock</strong> <em>(<var>fcn</var>)</em></dt> <dd><p>Unlock the named function <var>fcn</var> so that it may be removed from memory with <code>clear</code>. </p> <p>If no function is named then unlock the current function. </p> <p><strong>See also:</strong> <a href="#XREFmlock">mlock</a>, <a href="#XREFmislocked">mislocked</a>, <a href="Persistent-Variables.html#XREFpersistent">persistent</a>, <a href="Status-of-Variables.html#XREFclear">clear</a>. </p></dd></dl> <a name="XREFmislocked"></a><dl> <dt><a name="index-mislocked"></a><em></em> <strong>mislocked</strong> <em>()</em></dt> <dt><a name="index-mislocked-1"></a><em></em> <strong>mislocked</strong> <em>(<var>fcn</var>)</em></dt> <dd><p>Return true if the named function <var>fcn</var> is locked in memory. </p> <p>If no function is named then return true if the current function is locked. </p> <p><strong>See also:</strong> <a href="#XREFmlock">mlock</a>, <a href="#XREFmunlock">munlock</a>, <a href="Persistent-Variables.html#XREFpersistent">persistent</a>, <a href="Status-of-Variables.html#XREFclear">clear</a>. </p></dd></dl> <hr> <div class="header"> <p> Next: <a href="Function-Precedence.html#Function-Precedence" accesskey="n" rel="next">Function Precedence</a>, Previous: <a href="Overloading-and-Autoloading.html#Overloading-and-Autoloading" accesskey="p" rel="prev">Overloading and Autoloading</a>, Up: <a href="Function-Files.html#Function-Files" accesskey="u" rel="up">Function Files</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> </div> </body> </html>