Re: [fpc-pascal] try..finally vs interfaces performance

[Graeme Geldenhuys]

On 2016-04-14 21:45, Luiz Americo Pereira Camara wrote:
> other class
> that implements addref method but does not automatically frees the instance
> when refcount is zero

I always considered that a bit of a hack. But yes, you are right.

Regards,
  Graeme

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Re: [fpc-pascal] try..finally vs interfaces performance

[Luiz Americo Pereira Camara]

2016-04-14 10:58 GMT-03:00 Graeme Geldenhuys 
:

> On 2016-04-14 14:15, Marcos Douglas wrote:
> > because you gain more than just automatic memory release.
>
> It is also worth noting that not all Interface usage means “automatic
> memory release”. If you use COM-style Interfaces, then yes you get
> memory management.


Not necessarily, you can use COM interfaces with TComponent or other class
that implements addref method but does not automatically frees the instance
when refcount is zero

Luiz
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Re: [fpc-pascal] try..finally vs interfaces performance

[Vincent Snijders]

2016-04-14 10:50 GMT+02:00 Michael Van Canneyt :

>
>
> On Thu, 14 Apr 2016, Mazola Winstrol wrote:
>
> Recently i did some maintenance in a code of a colleague. I realized that
>> he designed several classes with interface support so he do not need to
>> protect the code blocks with try..finally to ensure that the instances are
>> released from memory.
>>
>> Theoretically, which solution has higher performance? The traditional
>> approach (code protected try..finally) or classes with interfaces (no need
>> to protect the code. by otherside, classes with interfaces support have
>> lock operations)?
>>
>>
> It should be exactly the same. As soon as interfaces are used the compiler
> inserts an implicit try...finally in a procedure.
> You can see this if you step through the code with GDB, the execution point
> will jump to the end of the procedure and then back to the beginning...
>
>
I would venture, that manually adding try finally would give you better
performance than using interfaces at the cost of writing more code and
therefore less clear and more error-prone source.

If you use interfaces, the compiler also adds reference counting, which you
don't have if you free the objects at the right places.

It is not sure if you can measure the difference in performance though.

Vincent
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Re: [fpc-pascal] try..finally vs interfaces performance

[Marcos Douglas]

On Thu, Apr 14, 2016 at 10:58 AM, Graeme Geldenhuys
 wrote:
> On 2016-04-14 14:15, Marcos Douglas wrote:
>> because you gain more than just automatic memory release.
>
> It is also worth noting that not all Interface usage means “automatic
> memory release”. If you use COM-style Interfaces, then yes you get
> memory management. If you use CORBA-style Interface, then no you don’t
> get memory management.

You're right, well remembered.
I use only COM-style Interfaces.

Regards,
Marcos Douglas
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Re: [fpc-pascal] try..finally vs interfaces performance

[Graeme Geldenhuys]

On 2016-04-14 14:15, Marcos Douglas wrote:
> because you gain more than just automatic memory release.

It is also worth noting that not all Interface usage means “automatic
memory release”. If you use COM-style Interfaces, then yes you get
memory management. If you use CORBA-style Interface, then no you don’t
get memory management.

Regards,
  Graeme

-- 
fpGUI Toolkit - a cross-platform GUI toolkit using Free Pascal
http://fpgui.sourceforge.net/

My public PGP key:  http://tinyurl.com/graeme-pgp
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Re: [fpc-pascal] try..finally vs interfaces performance

[Marcos Douglas]

On Thu, Apr 14, 2016 at 5:19 AM, Mazola Winstrol  wrote:
> Recently i did some maintenance in a code of a colleague. I realized that he
> designed several classes with interface support so he do not need to protect
> the code blocks with try..finally to ensure that the instances are released
> from memory.
>
> Theoretically, which solution has higher performance? The traditional
> approach (code protected try..finally) or classes with interfaces (no need
> to protect the code. by otherside, classes with interfaces support have lock
> operations)?

Hi,

I don't know the answer but I think should be exactly the same.
Even if not, I strongly recommend you to use interfaces instead
"try-finally" approach
because you gain more than just automatic memory release.

Regards,
Marcos Douglas

PS. I have a blog about Object Pascal. I write about real
object-oriented approach.
The blog is written in Portuguese but using Google Translate I guess
you won't have
problems to translate.

http://objectpascalprogramming.com/
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Re: [fpc-pascal] try..finally vs interfaces performance

[Michael Van Canneyt]

On Thu, 14 Apr 2016, Mazola Winstrol wrote:


Recently i did some maintenance in a code of a colleague. I realized that
he designed several classes with interface support so he do not need to
protect the code blocks with try..finally to ensure that the instances are
released from memory.

Theoretically, which solution has higher performance? The traditional
approach (code protected try..finally) or classes with interfaces (no need
to protect the code. by otherside, classes with interfaces support have
lock operations)?



It should be exactly the same. 
As soon as interfaces are used the compiler inserts an implicit try...finally in a procedure.

You can see this if you step through the code with GDB, the execution point
will jump to the end of the procedure and then back to the beginning...

Michael.
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Re: [fpc-pascal] try..finally vs interfaces performance

[Graeme Geldenhuys]

On 2016-04-14 09:19, Mazola Winstrol wrote:
> Theoretically, which solution has higher performance?

Interesting question. As for the answer I have no idea. Why don't you
put a quick test together. Loop the code 10,000 or 100,000 times and
time the results. Please share your test code and answer if you don't mind.

Regards,
  Graeme

-- 
fpGUI Toolkit - a cross-platform GUI toolkit using Free Pascal
http://fpgui.sourceforge.net/

My public PGP key:  http://tinyurl.com/graeme-pgp
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[fpc-pascal] try..finally vs interfaces performance

[Mazola Winstrol]

Recently i did some maintenance in a code of a colleague. I realized that
he designed several classes with interface support so he do not need to
protect the code blocks with try..finally to ensure that the instances are
released from memory.

Theoretically, which solution has higher performance? The traditional
approach (code protected try..finally) or classes with interfaces (no need
to protect the code. by otherside, classes with interfaces support have
lock operations)?

Regards
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