📄 lib0005.html
字号:
<html>
<META http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>Organization</title>
<link rel="STYLESHEET" type="text/css" href="images/xpolecat.css">
<link rel="STYLESHEET" type="text/css" href="images/ie.content.books24x7.css">
</head>
<body >
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<td><div STYLE="MARGIN-LEFT: 0.15in;">
<a href="toc.html"><img src="images/teamlib.gif" width="62" height="15" border="0" align="absmiddle" alt="Team LiB"></a></div></td>
<td valign="top" class="v2" align="right"><div STYLE="MARGIN-RIGHT: 0.15in"><a href="LiB0004.html"><img src="images/previous.gif" width="62" height="15" border="0" align="absmiddle" alt="Previous Section"></a>
<a href="LiB0006.html"><img src="images/next.gif" width="41" height="15" border="0" align="absmiddle" alt="Next Section"></a>
</div></td></tr>
</table>
<div class="preface">
<a name="intro"></a>
<div class="section">
<h2 class="first-section-title"><a name="27"></a><a name="introlev1sec4"></a>Organization</h2><p class="first-para">This book is divided into six chapters. I will start from the ground up and try to provide a comprehensive, but detailed, view of memory management fundamentals. Because of this, each chapter builds on what has been presented in the previous one. Unless you are a memory management expert, the best way to read this book is straight through.</p>
<div class="section">
<h3 class="sect3-title">
<a name="28"></a><a name="introlev2sec1"></a><a class="chapterjump" href="LiB0012.html#49">Chapter 1</a> - Memory Management Mechanisms</h3>
<p class="first-para">The first chapter presents a detailed look at the machinery that allows memory management to take place. Almost every operating system in production takes advantage of facilities that are provided by the native processor. This is done primarily for speed, since pushing repetitive bookkeeping down to the hardware benefits overall performance. There have been attempts by some engineers to track and protect memory strictly outside of the hardware. But speed is key to the hardware realm, and this fact always forces such attempts off of the playing field. The end result is that understanding how memory management is performed means taking a good look at how memory hardware functions.</p>
<a></a>
</div>
<div class="section">
<h3 class="sect3-title">
<a name="29"></a><a name="introlev2sec2"></a><a class="chapterjump" href="LiB0019.html#131">Chapter 2</a> - Memory Management Policies</h3>
<p class="first-para">Computer hardware provides the mechanism for managing memory, but the policy decisions that control how this mechanism is applied are dictated by the operating system and its system call interface to user programs. In this chapter, the memory management components provided by the operating system are analyzed and dissected. This will necessarily involve taking a good, hard look at the internals of production operating systems like Linux and Windows.</p>
<p class="para">In general, hardware always provides features that are ahead of the software that uses it. For example, Intel's Pentium provides four distinct layers of memory protection. Yet, I could not find a single <a name="30"></a><a name="IDX-xx"></a>operating system that took advantage of all four layers. All the systems that I examined use a vastly simplified two-layer scheme.</p>
<table border="0" cellspacing="0" cellpadding="0" class="note">
<tr>
<td valign="top" class="admon-check"></td><td valign="top" class="admon-title">Note </td><td valign="top" class="admon-body">
<p class="first-para">The relationship between hardware and software is analogous to the relationship between mathematics and engineering. Mathematics tends to be about 50 years ahead of engineering, which means that it usually takes about 50 years for people to find ways to apply the theorems and relationships that the mathematicians uncover.</p>
</td>
</tr>
</table>
<a></a>
</div>
<div class="section">
<h3 class="sect3-title">
<a name="31"></a><a name="introlev2sec3"></a><a class="chapterjump" href="LiB0032.html#418">Chapter 3</a> - High-Level Services</h3>
<p class="first-para">Above the hardware and the cocoon of code that is the operating system are the user applications. Because they are insulated from the inner workings of the operating system, applications have an entirely different way to request, use, and free memory. The manner in which a program utilizes memory is often dependent on the language in which the program was written. This chapter looks at memory management from the perspective of different programming languages. This chapter also serves as a launch pad for the next two chapters by presenting an overview of memory management at the application level.</p>
<a></a>
</div>
<div class="section">
<h3 class="sect3-title">
<a name="32"></a><a name="introlev2sec4"></a><a class="chapterjump" href="LiB0032.html#418">Chapter 4</a> - Manual Memory Management</h3>
<p class="first-para">In <a href="LiB0032.html#418" target="_parent" class="chapterjump">Chapter 4</a>, a number of manual memory management algorithms are presented in explicit detail. The algorithms are presented in theory, implemented in C++, and then critiqued in terms of their strengths and weaknesses. The chapter ends with suggestions for improvements and a look at certain hybrid approaches.</p>
<a></a>
</div>
<div class="section">
<h3 class="sect3-title">
<a name="33"></a><a name="introlev2sec5"></a><a class="chapterjump" href="LiB0041.html#534">Chapter 5</a> - Automatic Memory Management</h3>
<p class="first-para">In <a href="LiB0041.html#534" target="_parent" class="chapterjump">Chapter 5</a>, a number of automatic memory management algorithms are examined. The algorithms are presented in theory, implemented in C++, and then critiqued in terms of their strengths and weaknesses. A significant amount of effort is invested in making this discussion easy to follow and keeping the reader focused on key points. Two basic garbage collectors are provided and compared to other, more advanced collection schemes.</p>
<a name="34"></a><a name="IDX-xxi"></a>
<a></a>
</div>
<div class="section">
<h3 class="sect3-title">
<a name="35"></a><a name="introlev2sec6"></a><a class="chapterjump" href="LiB0046.html#637">Chapter 6</a> - Miscellaneous Topics</h3>
<p class="first-para">This chapter covers a few special-purpose subjects that were difficult to fit into the previous five chapters. For example, I describe how to effectively implement a suballocator in a compiler. I also take a look at how memory management subsystems can be made to provide dynamic algorithm support at run time via a microkernel architecture.</p>
<a></a>
</div>
<a></a>
</div>
</div>
</div>
</div>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<td><div STYLE="MARGIN-LEFT: 0.15in;">
<a href="toc.html"><img src="images/teamlib.gif" width="62" height="15" border="0" align="absmiddle" alt="Team LiB"></a></div></td>
<td valign="top" class="v2" align="right"><div STYLE="MARGIN-RIGHT: 0.15in"><a href="LiB0004.html"><img src="images/previous.gif" width="62" height="15" border="0" align="absmiddle" alt="Previous Section"></a>
<a href="LiB0006.html"><img src="images/next.gif" width="41" height="15" border="0" align="absmiddle" alt="Next Section"></a>
</div></td></tr>
</table>
</body>
</html>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -