Delete the large object in ironpython, and instantly release the memory?

Question

I am a creating a huge mesh object (some 900 megabytes in size). Once I am done with analysing it, I would like to somehow delete it from the memory.

I did a bit of search on stackoverflow.com, and I found out that del will only delete the reference to mentioned mesh. Not the mesh object itself. And that after some time, the mesh object will eventually get garbage collected.

Is gc.collect() the only way by which I could instantly release the memory, and there for somehow remove the mentioned large mesh from the memory? I've found replies here on stackoverflow.com which state that gc.collect() should be avoided (at least when it comes to regular python, not specifically ironpython). I've also find comments here on stackoverflow which claim that in IronPython it is not even guaranteed the memory will be released if nothing else is holding a reference.

Any comments on all these issues?

I am using ironpython 2.7 version.

Thank you for the reply.

Answer 1

In general managed enviroments relase there memory, if no reference is existing to the object anymore (from connection from the root to the object itself). To force the .net framework to release memory, the garbage collector is your only choice. In general it is important to know, that GC.Collect does not free the memory, it only search for objects without references and put the in a queue of objects, which will be released. If you want to free memory synchron, you also need GC.WaitForPendingFinalizers.

One thing to know about large objects in the .net framework is, that they are stored seperatly, in the Large Object Heap (LOH). From my point of few, it is not bad to free those objects synchron, you only have to know, that this can cause some performance issues. That's why in general the GC decide on it's own, when to collect and free memory and when not to.

Because gc.collect is implemented in Python as well as in IronPython, you should be able to use it. If you take a look at the implementation in IronPython, gc.collect does exactly what you want, call GC.Collect() and GC.WaitForPendingFinalizer. So in your case, i would use it.

Hope this helps.