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diff --git a/doc/html/emb-performance.html b/doc/html/emb-performance.html deleted file mode 100644 index 9aa59f5d7..000000000 --- a/doc/html/emb-performance.html +++ /dev/null @@ -1,132 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> -<!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/doc/qws.doc:532 --> -<html> -<head> -<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> -<title>TQt/Embedded Performance Tuning</title> -<style type="text/css"><!-- -fn { margin-left: 1cm; text-indent: -1cm; } -a:link { color: #004faf; text-decoration: none } -a:visited { color: #672967; text-decoration: none } -body { background: #ffffff; color: black; } ---></style> -</head> -<body> - -<table border="0" cellpadding="0" cellspacing="0" width="100%"> -<tr bgcolor="#E5E5E5"> -<td valign=center> - <a href="index.html"> -<font color="#004faf">Home</font></a> - | <a href="classes.html"> -<font color="#004faf">All Classes</font></a> - | <a href="mainclasses.html"> -<font color="#004faf">Main Classes</font></a> - | <a href="annotated.html"> -<font color="#004faf">Annotated</font></a> - | <a href="groups.html"> -<font color="#004faf">Grouped Classes</font></a> - | <a href="functions.html"> -<font color="#004faf">Functions</font></a> -</td> -<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>TQt/Embedded Performance Tuning</h1> - - -When building embedded applications on low-powered devices, a number -of options are available that would not be considered in a desktop -application environment. These options reduce the memory and/or CPU -requirements at the cost of other factors. -<p> <ul> -<li> <a href="emb-features.html"><b>Tuning the functionality of TQt</a> -<li> <a href="#general">General programming style</a> -<li> <a href="#static">Static vs. Dynamic linking</a> -<li> <a href="#alloc">Alternative memory allocation</a> -</ul> -<p> <a name="general"></a> -<h2> General programming style -</h2> -<a name="1"></a><p> The following guidelines will improve CPU performance: -<ul> -<li> Create dialogs and widgets once, then <a href="tqwidget.html#hide">TQWidget::hide</a>() and -<a href="tqwidget.html#show">TQWidget::show</a>() them, rather than creating them and deleting -them every time they are needed. -This will use a little more memory, but will be much faster. -Try to create them the first time "lazily" to avoid slow -startup (e.g. only create a Find dialog the first time the -user invokes it). -</ul> -<p> <a name="static"></a> -<h2> Static vs. Dynamic linking -</h2> -<a name="2"></a><p> A lot of CPU and memory is used by the ELF linking process. You can -make significant savings by using a static build of your application -suite. This means that rather than having a dynamic library (<tt>libtqte.so</tt>) and a collection of executables which link dynamically to -that library, you build all the applications into a single executable -and statically link that with a static library (<tt>libtqt.a</tt>). This -improves start-up time, and reduces memory usage, at the expense of -flexibility (to add a new application, you must recompile the single -executable) and robustness (if one application has a bug, it might -harm other applications). If you need to install end-user -applications, this may not be an option, but if you are building a -single application suite for a device with limited CPU power and -memory, this option could be very beneficial. -<p> To compile TQt as a static library, add the <tt>-static</tt> options when -you run configure. -<p> To build your application suite as an all-in-one application, design each -application as a stand-alone widget or set of widgets, with only minimal -code in the main() function. Then, write an application that gives -some way to switch between the applications (e.g. a <a href="tqiconview.html">TQIconView</a>). -<a href="http://www.trolltech.com/products/qtopia/index.html">TQtopia</a> is an example of this. It can be built either as a set of -dynamically linked executables, or as a single static application. -<p> Note that you should generally still link dynamically against the -standard C library and any other libraries which might be used by -other applications on your device. -<p> <a name="alloc"></a> -<h2> Alternative memory allocation -</h2> -<a name="3"></a><p> We have found that the libraries shipped with some C++ compilers on -some platforms have poor performance in the built-in "new" and "delete" -operators. You might gain performance by re-implementing these -functions. For example, you can switch to the plain C allocators -by adding the following to your code: -<p> <pre> - void* operator new[]( size_t size ) - { - return malloc( size ); - } - - void* operator new( size_t size ) - { - return malloc( size ); - } - - void operator delete[]( void *p ) - { - free( p ); - } - - void operator delete[]( void *p, size_t size ) - { - free( p ); - } - - void operator delete( void *p ) - { - free( p ); - } - - void operator delete( void *p, size_t size ) - { - free( p ); - } -</pre> - - -<!-- eof --> -<p><address><hr><div align=center> -<table width=100% cellspacing=0 border=0><tr> -<td>Copyright © 2007 -<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a> -<td align=right><div align=right>TQt 3.3.8</div> -</table></div></address></body> -</html> |