Re: [Vala] benchmarks on Vala?

[Дмитрий Романов <romanovda gmail com>]

It is well known thing in C++ that calling a "new" for creating a new
classes costs. Especially "framework" classes (i.e. root.cern.ch) with
virtual table and probably reloaded  new operator (but still based on malloc
heap allocation) gains approximately the same performance on creation as was
shown for VALA in this thread.

So if you need to have "empty" objects fast (for example in loops) you
should better not to create but clear and reuse.

If you really need to populate your memory with 100,000 objects, you'd
better to have as few as possible memory allocation times.
Have somebody tried creating this objects not one by one but in arrays?

But in normal programming the overhead of creating the new objects vs.
reusing old ones usually is less than 4%.


For the .NET C# (should be same for Mono) "new" operation is not based on
malloc heap allocation, but is based on allocation from some buffer called
managed heap. So the "new" operation is really fast for .NET C#. If you will
use .Clear() method of your class while C# users call "new" you will beat
C#.
Good  article about memory allocation
http://msdn.microsoft.com/en-us/magazine/bb985010.aspx (part 1)
http://msdn.microsoft.com/en-us/magazine/bb985011.aspx (part 2)
article on how much things costs
http://msdn.microsoft.com/en-us/library/ms973852.aspx
Some article on garbage collector performance
http://msdn.microsoft.com/en-us/library/ms973837.aspx

This "managed heap" is preallocated, but in case of malloc you always get
the amount of memory you need. Thus you can see "but more memory efficient".
It is not really efficiency for long term software living because managed
heap may grow or shrink depending on memory usage. In real project one can
gain efficiency in this only if one will pay much much attention to this.




2011/1/19 pancake <pancake youterm com>

> On 01/18/11 01:54, "Andrés G. Aragoneses" wrote:
>
> > On 17/01/11 14:08, Jiří Zárevúcky wrote:
> >
> > > On Mon, Jan 17, 2011 at 1:24 AM, Didip Kerabat<didipk gmail com>  wrote:
> > >
> > > I don't know about any recent benchmarks, but I think Vala will
> > > generally be a bit slower than Mono, but more memory efficient.
> >
> > Slower, really?
> >
> > Would that be true as well for the dova profile?
> i think (not demonstrated) that vala is faster than mono on normal
> situations where you
> don't build over nine thousand objects per second.
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