Tuesday, July 27, 2010

Pretending you know what you're talking about - a book review

Some books in Computer Science seem to do just that: pretending they know what they are talking about, when they in fact do not.

A quote on this, not restricted to Java books:
Most Java books are written by people who couldn't get a job as a Java programmer (since programming almost always pays more than book writing; I know because I've done both). These books are full of errors, bad advice, and bad programs.
Peter Norvig, Director of Research at Google, Inc.

I have seen such books myself. But they do not get great reviews at Amazon and they do not get slashdotted.
Instead, Virtual Machine Design and Implementation in C/C++ does. Its author is great at pretending he knows what he is talking about. I started looking at it for my seminar on Virtual Machines, hoping to make some use of it, and I was deeply disappointed. Looking at the table of contents and index, Virtual Machines: Versatile Platforms for Systems and Processes seems to be a better book on the topic , which covers also system virtualization (a different topic having the same name), however I cannot really judge.
Virtual Machines, by Iain D. Craig, seems instead devoted to semantic issues, and I am not qualified to judge that topic, only to say it is different.
Back to the first book, after reading sample pages from Amazon preview (mostly the table of contents and the index), together with all Amazon reviews, I realized what is happening here.

So, the rest of this post is a (meta-?)review against this book - which is much less interesting, unless you were actually considering to buy it.



The author does know what he is talking about, and spent lots of time polishing it, he's just totally unaware that it is completely unrelated to the title of the book, since he has no experience in the field. Reading the introduction after reading the above quote is enlightening - the author mentions being poor (page xvii), and his experience (described at page iv), like writing CASE tools in Java, is totally unrelated - if he couldn't get a better job, I'd say Norvig's quote is exactly about him. And after reading this, the mention he makes about when "he used to disable paging and run on pure SDRAM" smells of a lamer wanting to show off (in other contexts, it could be just a joke, I know).

The author is just trying to learn by himself how to implement an emulator, and writing a diary on this. If you care about real Virtual Machines (Parrot, the JVM, .NET, and so on), you need entirely different material. Say, JIT compilation. Other reviews mention some more points which are missing, but none of them had a real introduction to the field, so they are not aware of how much else is not in the book. Actually, maybe he knows how a VM looks from outside, but his attempts to move in that direction (like support for multithreading) look quite clumsy - he talks about that and then does not manage to implement it.

Finally, the author seems to be an assembler programmer who is programming assembler in C++. As we remember, it is famously known that "the determined Real Programmer can write Fortran programs in any language", and it is still true with Assembler. Things like manual loop unrolling on debug statements (mentioned in reviews) are quite funny.

In the end, I'd recommend this book to nobody - it might contain some interesting stuff about the actual topic, asa acknowledged by some reviews, but I would not buy a book because of this hope. Especially, not for who cares about Virtual Machines.

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