Question

I have an object, which lives forever. I am deleteing all references I can see, to it after using it, but it still not collected. Its life cycle is pretty sophisticated so I can’t be sure that all references been cleared.

if ( container.Controls.Count > 0 )
{ 
    var controls = new Control[ container.Controls.Count ];
    container.Controls.CopyTo( controls, 0 );

    foreach ( var control in controls ) 
    { 
         container.Controls.Remove( control );
         control.Dispose();
    }

    controls = null; 
}

GC.Collect();
GC.Collect(1);
GC.Collect(2);
GC.Collect(3);

How can I find out what references does it still have? Why is it not collected?

Answer 1

Try using a memory profiler, (e.g. ants) it will tell you what is keeping the object alive. Trying to 2nd guess this type of problem is very hard.

Red-gate gives 14 days trial that should be more then enough time to tack down this problem and decide if a memory profiler provides you with long term value.

There are lots of other memory profilers on the market (e.g. .NET Memory Profiler) most of them have free trials, however I have found that the Red-Gate tools are easy to use, so tend try them first.