Do AAs allocate on removal?

[Gerrit Wichert]

Hello,

I'm just bitten by some occasional finalize exceptions in a wxd program 
I'm writing on a OpenSuse 64 bit linux host with dmd 2.64.2.

I was able to track it down to a bug in wxd, where the wxObject 
destructor tried to remove the object from a static map.

some code from wxObject:

        ~this()
        {
            Dispose();
        }

        public /+virtual+/ void Dispose()
        {
            if (wxobj != IntPtr.init)
            {
            //    bool still_there = RemoveObject(wxobj);

            //    lock (typeof (wxObject)) {
                    if (memOwn /*&& still_there*/)
                    {
                        dtor();
                    }
            //    }

                RemoveObject(wxobj);
                wxobj = IntPtr.init;
            //    memOwn = false;
            }
            //GC.SuppressFinalize(this);
        }

        // Removes a registered object.
        // returns true if the object is found in the
        // Hashtable and is removed (for Dispose)

        public static bool RemoveObject(IntPtr ptr)
        {
            bool retval = false;

            if (ptr != IntPtr.init)
            {
                if(ptr in objects) {
                  //gw 20131207 objects.remove(ptr); <-- here the 
application goes boom, so i replaced it with the following line
                  objects[ptr] = null;
                  retval = true;
                }
            }

            return retval;
        }

        // Hashtable to associate C++ objects with D references
        private static wxObject[IntPtr] objects;



As you can see, the problem is that wxObject destructor tried to remove 
an entry from a static AA. Replacing the removal with just nulling the 
value solves the problem. But now I have to implement a cyclic cleanup 
routine wich removes the nulls from the AA. I really don't want to do that.

I suspect that the AA reorganized (with allocation) when an element is 
removed. I think it is a good idee if this can be delayed until the next 
insert, so that remove can be used in finalizers.

I also don't have a clue why the object gets collected when it is 
referenced in the static map.


Gerrit Wichert