If using one DbContext instance per request, should I dispose the context on each request as well:

Question

I have implemented a base controller that instantiates a new DbContext per request:

public class BaseController: Controller
{
    protected HawkHeadDbContext Db { get; set; }

    protected override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        base.OnActionExecuting(filterContext);
        Db = new HawkHeadDbContext();
    }

    protected override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        base.OnActionExecuted(filterContext);
        Db.SaveChanges();
        Db.Dispose();
    }
} 

I am just a little worried that the Dispose call could become CPU intensive, and maybe I should dispose the context in the Dispose method of BaseController . I suspect the controller is instantiated for each request, but not sure if Dispose is called after each request, or in a regular 'DisposeAllControllers' type operation.

Answer 1

The context is designed for short time lifetime. Usually you see it in

using(var ctx = new DbContext())
{
    ...
}

Which means ctx.Dispose is called just after end of use.

More details here , see "lifetime" section.

So regarding your code, if you aren't using dependency injection (In which case you would have configured dbcontext as per request) you are doing well disposing it after action execution.

The only concern would be what if you call child actions.. In that case you may end having more than one dbcontext per request