Ayende @ Rahien

Hi!
My name is Oren Eini
Founder of Hibernating Rhinos LTD and RavenDB.
You can reach me by phone or email:

ayende@ayende.com

+972 52-548-6969

, @ Q c

Posts: 5,953 | Comments: 44,411

filter by tags archive

Solving the HttpModule mess


Okay, I think that I managed to dechiper most of the strange behavior in ASP.Net's Http Modules.
  • An AppDomain may hold zero or more instances of HttpApplication
  • A new instance of HttpApplication may be created (for reasons that I have not been able to figure out) - a set of all the http modules will be created as well.
  • An instnace of HttpApplication may be disposed (with its associted http modules) at any time.
  • A request will always be served by a fully initialized HttpApplication.
The result of this is that you cannot set/unset static variables from an HttpModule or HttpApplication.
Or, more correctly, you can't rely on unsetting a static varaible in Dispose() and setting it in Init() (or Application_Start and Application_End), since they may be called several times.
This mean that you either have to do a ref counting ( Bad ), or implement application level variables in Web secanrios. (Or just forgo about cleaning resources when the HttpApplication is going down).

I chose the first way, but it is not very clean, in my opion, check out the changes that I had to make:
Basically, this means that when running under Web context, it will use the current application as a global variable, and when running under non-web context, it will use a static variable.


Comments

Comment preview

Comments have been closed on this topic.

FUTURE POSTS

No future posts left, oh my!

RECENT SERIES

  1. The RavenDB Comic Strip (3):
    28 May 2015 - Part III – High availability & sleeping soundly
  2. Special Offer (2):
    27 May 2015 - 29% discount for all our products
  3. RavenDB Sharding (3):
    22 May 2015 - Adding a new shard to an existing cluster, splitting the shard
  4. Challenge (45):
    28 Apr 2015 - What is the meaning of this change?
  5. Interview question (2):
    30 Mar 2015 - fix the index
View all series

Syndication

Main feed Feed Stats
Comments feed   Comments Feed Stats