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📁 Memory Management—Algorithms and implementation in C/C++ Introduction Chapter 1 - Memory Manag
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<h2 class="first-section-title"><a name="22"></a><a name="introlev1sec2"></a>Impartial Analysis</h2><a name="23"></a><a name="IDX-xvii"></a>
<p class="para">In this book, I try very hard to offer memory management solutions without taking sides. I have gone to great lengths to present an unbiased discussion. This is important because it is extremely tempting to champion a certain memory management algorithm (especially if you invented it). There are some journal authors who would have you believe that their new algorithm is a panacea to cure the ills of the world. I do not have the ulterior motives of a college professor. I am here to offer you a set of tools and then let you decide how best to use them. In this book, I will present you with different techniques and try to point out the circumstances in which they perform well.</p>
<p class="para">The question "Which is the best memory management algorithm?" is very similar in spirit to any of the following questions:</p>
<ul class="simple-list">
<li class="first-listitem">
<p class="first-para">"Which operating system is the best?"</p>
</li>
<li class="listitem">
<p class="first-para">"Which programming language is the best?"</p>
</li>
<li class="listitem">
<p class="first-para">"Which data structure is the best?"</p>
</li>
<li class="listitem">
<p class="first-para">"Which type of screwdriver is the best?"</p>
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</ul>
<p class="para">I can recall asking a program manager at Eaton Corp., John Schindler, what the best operating system was. John was managing at least a dozen different high-end platforms for Eaton, and I thought he would know. I was expecting him to come right back with a quick answer like: "Oh, OpenBSD is the best." What actually happened was something that surprised me. He looked at me for a minute, as if the question was absurd. Then he smiled and said, "Well, it really depends on what you're going to use the machine for. I use Solaris for networking, HP-UX for app servers, AIX to talk to our mainframe, NT for mail, ..."</p>
<p class="para">The truth is there is no "best" solution. Most solutions merely offer certain trade-offs. In the end, the best tool to use will depend upon the peculiarities of the problem you are trying to solve.</p>
<p class="para">This is a central theme that appears throughout the domain of computer science. Keep it in the back of your mind, like some sort of Buddhist mantra:</p>
<p class="para">"There is no best solution, Grasshopper, only trade-offs."</p>
<p class="last-para">For example, linked lists and arrays can both represent a linear set of items. With a linked list, you get easy manipulation at the expense of speed. Adding an element to a linked list is as easy as modifying a couple of pointers. However, to find a given list <a name="24"></a><a name="IDX-xviii"></a>element, you may have to traverse the entire list manually until you find it. Conversely, with an array, you get access speed at the expense of flexibility. Accessing an array element is as easy as adding an integer to a base address, but adding and deleting array elements requires a lot of costly shifting. If your code is not going to do a lot of list modification, an array is the best choice. If your code will routinely add and delete list members, a linked list is the better choice. It all depends upon the context of the problem.</p>
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