[.Net] Static Classes in Web Applications - Tilted Forum Project Discussion Community

Moskie · 11-13-2004, 08:08 AM

I was having a discussion with someone I'm developing a web applcation with about the use of static classes ("shared" in VB). He's pretty adamant about *not* using them; at least he can't think of a particular situation where he'd want to use them. He doesn't like the idea of unnecessary things taking up space in memory when no users are logged in. I think that's unnecessarily stingy, but whatever.

So I got to thinking about it, and I had some questions. For a web application, at what level are static classes loaded? (The options being at application start, at session start, and at request start.) Initially, I assumed it was at application start, which seems like the only situation where the class is actually "static". But, if that's the case, does one have to worry about threading issues when dealing with static classes? For example, if two requests are made at nearly the same time, and they both make use of a particular static function, what happens when the second request makes the call to the funtion before the first call is finished? I really hope this doesn't mean that you have to work with semaphores when writing static classes for web apps.

The more I think about it, the more unsure I am about what the outcome would be! Any thoughts?

a-j · 11-15-2004, 04:05 PM

First of all, certain aspects of OOD "require" the use of static classes. Take a look at the Singleton pattern, in nearly every large project I've done the Singleton pattern pops up again and again, and trying to do it without static classes introduces numerous problems.

Stompy · 11-18-2004, 08:56 AM

I've read from many places that static methods are faster than instanced methods anyway.

I use em ALL the time.

For example... say I have a class "Customer" and I want to add a new customer to the DB. I have a static void method "Add" on customer and pass in the customer object's reference and a reference to the currently opened DB connection.

Something like:

Code:

Customer cust = new Customer();
cust.FirstName = "Blah";
cust.LastName = "Blah";
...

Customer.Add(ref cust, ref dbConn);

The only time you need to worry about threading issues is when you make static fields. If you make static methods and pass what you need into them, there won't be any threading issues.

You can test this out by making a simple windows app w/ two buttons that calls a function similar to the following:

Code:

public static void Test(int x)
{
      System.Diagnostics.Debug.WriteLine("x = " + x.ToString());
      Thread.Sleep(10000); //Sleep 10 seconds
      System.Diagnostics.Debug.WriteLine("x = " + x.ToString());
}

Click the first button, which passes in a certain x value, and do the same with the second button a few seconds later.

You'll see the methods retain their values.

If you did something as shown below and referened THAT x instead, then the values would be overwritten.

Code:

public class Test
{
     public static int x;
     public Test(){}
     ...
}

But yeah, using static methods is perfectly fine, and from what I've read, even better than calling instanced methods.

11-13-2004, 08:08 AM	#1 (permalink)
Moskie Pure Chewing Satisfaction Location: can i use bbcode [i]here[/i]?	[.Net] Static Classes in Web Applications I was having a discussion with someone I'm developing a web applcation with about the use of static classes ("shared" in VB). He's pretty adamant about not using them; at least he can't think of a particular situation where he'd want to use them. He doesn't like the idea of unnecessary things taking up space in memory when no users are logged in. I think that's unnecessarily stingy, but whatever. So I got to thinking about it, and I had some questions. For a web application, at what level are static classes loaded? (The options being at application start, at session start, and at request start.) Initially, I assumed it was at application start, which seems like the only situation where the class is actually "static". But, if that's the case, does one have to worry about threading issues when dealing with static classes? For example, if two requests are made at nearly the same time, and they both make use of a particular static function, what happens when the second request makes the call to the funtion before the first call is finished? I really hope this doesn't mean that you have to work with semaphores when writing static classes for web apps. The more I think about it, the more unsure I am about what the outcome would be! Any thoughts? __________________ Greetings and salutations. Last edited by Moskie; 11-13-2004 at 08:18 AM..

11-18-2004, 08:56 AM	#3 (permalink)
Stompy Banned from being Banned Location: Donkey	I've read from many places that static methods are faster than instanced methods anyway. I use em ALL the time. For example... say I have a class "Customer" and I want to add a new customer to the DB. I have a static void method "Add" on customer and pass in the customer object's reference and a reference to the currently opened DB connection. Something like: Code: Customer cust = new Customer(); cust.FirstName = "Blah"; cust.LastName = "Blah"; ... Customer.Add(ref cust, ref dbConn); The only time you need to worry about threading issues is when you make static fields. If you make static methods and pass what you need into them, there won't be any threading issues. You can test this out by making a simple windows app w/ two buttons that calls a function similar to the following: Code: public static void Test(int x) { System.Diagnostics.Debug.WriteLine("x = " + x.ToString()); Thread.Sleep(10000); //Sleep 10 seconds System.Diagnostics.Debug.WriteLine("x = " + x.ToString()); } Click the first button, which passes in a certain x value, and do the same with the second button a few seconds later. You'll see the methods retain their values. If you did something as shown below and referened THAT x instead, then the values would be overwritten. Code: public class Test { public static int x; public Test(){} ... } But yeah, using static methods is perfectly fine, and from what I've read, even better than calling instanced methods. __________________ I love lamp.

11-15-2004, 04:05 PM	#2 (permalink)
a-j Tilted	First of all, certain aspects of OOD "require" the use of static classes. Take a look at the Singleton pattern, in nearly every large project I've done the Singleton pattern pops up again and again, and trying to do it without static classes introduces numerous problems.