Thread safety on Application Start

Question

I have an ASP.NET application in which I am writing this code in Application_OnStart event:

public virtual void OnStart(HttpApplication httpApplication)
{
    MyClass.PopulateIndices();
}

Now, I know that App_Onstart is fired only once, so my question is: do I need to add thread safety in this code, like:

lock(some object)
{
    MyClass.PopulateIndices();
}

Is this lock() really needed? Can multiple threads fire App OnStart simultaneously?

Jeffersonjeffery

Answer 1

It will be called just once. Definitely. You don't need any lock there.

From MSDN:

The Application_Start method is called only one time during the life cycle of an application.

Source: http://msdn.microsoft.com/en-us/library/ms178473.aspx

Hindermost

What if i am using same app's folder for a few website, it still called once ? How can i reproduce this ? – Ralaigh

Answer 2

I tested this with some logging and Application_Start is executed only once (while, for example, Session_Start is executed at every user' session start).

you won't need the lock.

Hecatomb

Answer 3

I recommend you just serviceAutoStartProviders if you are using .NET 4.0 instead:

Auto-Start ASP.NET Applications (VS 2010 and .NET 4.0 Series)

Bossuet