[ILUG] Re: [linux-edu] war games?

[Mark Fallon]

Paul Jakma wrote:
> 
> nice. must remember that one. :)
> 
> am i right in thinking that to do the below without goto would be
> difficult to do legibly?
> 
> ie goto enhances readibility/structure of this?
> 

Well I can see a few ways to do this but none of them are as
clean or as easy to modify e.g.:

Use a set of nested 'if' statements, then use the error value passed
to a 'case' statement to do the releasing of resources. Main problem
here would be that the error values returned by most functions would not
usually not be fine grained enough to do the releasing of resources.

Use the 'else' branch of the 'if' statements to do the resource
releasing.
This would result in a lot of repetition of commands which would have
knock on affects on how maintainable the code was as well as the
possiblity
of introducing bugs. Yes you could cut and paste the lines from one
block to
the next but you must remember if you fix a bug in one else block
to fix it in all the others.

You could check the resource handle for each resource and release it if
it was valid. This might not always be possible. Adds lots of if
statements
to the end of your function. 

I am sure there are other ways to code this type of problem.

So the goto's enchance the readability / structure / maintainability and
speed
of this code. 

I would very rarely use goto's in any of my code. They can cause a many
problems
as they solve. This is one case where I would consider using them
though.

Regards,

Mark
 
_______________________________________________________________

Mark Fallon			E-mail : Mark.Fallon at oracle.com
Senior Software Engineer	Phone  : +353-1-8033207
Global Product Engineering	Fax    : +353-1-8033221
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