Historical errata for The dRuby Book

Under “1.2 Building the Reminder Application,” the three methods of the Reminder class are listed: “It has three methods: Add, delete, and to_a.” The “Add” method described should be called “add.”

My “r = DRbObject.new_with_uri(‘druby://localhost:12345’)” call hung, but using a —noreadline option to irb didn’t fix it (and I didn’t need the option for the first example, so I think I’m OK without it).

I fixed the hang. After starting the server by calling:
s = DRb.start_service(‘druby://localhost:12345’, front)

I did a:
s.thread.join

After doing this, the hanging client returned and the example worked fine.

I am running Ruby 1.9.2p290 on OSX 10.7.3

Page 221 - CG instead of GC — from customer feedback.

The figure 36 description is reversed. It should say down is equivalent to take and up is equivalent to write. Text currently says:

Figure 36—The implementation of a semaphore using TupleSpace. The down method is equivalent to write, and the up method is equivalent to take.

Duplicated sentence on second and third paragraph:

“Consider a program … completed phase n.”

change:
>> str.id
=> 358800978
to:
>> str.id
=> 358800978

code examples miss “require ‘Date’” statement at the top, otherwise error "…/shipping_notify.rb:60:in `

In the code example, it says “oops”, though other lines has “oops,” and “oops.”. These comma and period are not necessary.

From
=>> #

To

=> #

From

DRBUnknown#reload

To

DRbUnknown#reload

exit - Terminate the thread.
wakeup - Change the thread in running mode.
run - Get the thread into running mode. Switch thread.
raise - Raise exception to the thread.

The verb should ends with “s” (eg: Terminates) to be consistent with method explanations in other pages

At tsstruct.rb

From

ensure @ts.write(tuple) if tuple

To

ensure
@ts.write(tuple) if tuple

From

Rwiki (a dRuby-powered wiki)

To

RWiki (a dRuby-powered wiki)

From

similar to Rail’s view helper)

To

similar to Rails’ view helper)

1. fork.rb

result = 0
pid = fork do
result += 1
end Process::waitpid(pid) p result

Missing indentation

From

>> >osx[:msg] = ‘linux box to osx’

To

>> osx[:msg] = ‘linux box to osx’

From

Changes URI to become method call to GW and W rap

To

Changes URI to become method call to GW and Wrap

Explanation about Thread.exclusive and Thread.critical is wrong
forums.pragprog.com/forums/198/topics/10553

In the second-to-last paragraph, “When you want to include it in a instance, ” should read “…an instance”.

Last paragraph: “Why do we need such functionalities?” should read “… functionality?”

Should the run state have double quotes around it?

In the third paragraph, last sentence, you have used the word “discovering” when you wanted to use the word “discover”. It should say, “… as you read and discover new things along the way.”.

In the page 33, IDL is explained as Interactive Data Language, instead Interface Definition Language.