instance control

[murali]

hi,

I want to create a class in C# that will only have 'n' instances at any
given time. If (n+1)th instance is requested, an Exception will be
thrown. These instances must be maintained in a collection in the
class. Note that once an instance is acquired, it can be released as
well.
thanks
murali

[Mark R. Dawson]

Hi Murali,
there is no native way in .Net to do this to an object. You can either
make an object pool which has a get and release method i.e.

MyObject ObjectPool.Get()
ObjectPool.Release(MyObject objectToRelease)

or you can build this into the object itself and have static methods:

class MyObject
{
//Stop anyone from creating these objects
private MyObject()
{
}

public static MyOBject Get()
{
}

public static void Release(MyObject object)
{
}
}

Which internally has a collection of MyObjects. Then you can get an
instance like:

MyObject x = MyObject.Get();
MyObject.Release(x);

Mark Dawson
http://www.markdawson.org
"murali@pune" wrote:

hi,

I want to create a class in C# that will only have 'n' instances at any
given time. If (n+1)th instance is requested, an Exception will be
thrown. These instances must be maintained in a collection in the
class. Note that once an instance is acquired, it can be released as
well.
thanks
murali

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

"murali@pune" <mu***********@gmail.com> wrote in message
news:11*********************@j33g2000cwa.googlegro ups.com...

hi,

I want to create a class in C# that will only have 'n' instances at any
given time. If (n+1)th instance is requested, an Exception will be
thrown. These instances must be maintained in a collection in the
class. Note that once an instance is acquired, it can be released as
well.

How they will be released ? by whom?

You said it will be kept in a collection so the class itself will have to
release them.

Take a look at the Singleton pattern
http://www.yoda.arachsys.com/csharp/singleton.html , you can extend it to
something like what you want.

Also a good idea to refresh the different locking mechanism
http://www.yoda.arachsys.com/csharp/.../locking.shtml

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

[Joanna Carter [TeamB]]

"murali@pune" <mu***********@gmail.com> a écrit dans le message de news:
11*********************@j33g2000cwa.googlegroups.c om...

| I want to create a class in C# that will only have 'n' instances at any
| given time. If (n+1)th instance is requested, an Exception will be
| thrown. These instances must be maintained in a collection in the
| class. Note that once an instance is acquired, it can be released as
| well.

Make the default constructor private and add a static method that will
control and return a number of instances; use a static field to keep track
of the count. You may have difficulty keeping track of instances being freed
as garbage collection is non-deterministic and can be difficult to track.

Joanna

--
Joanna Carter [TeamB]
Consultant Software Engineer