The concerns about properties is one that i hit intially as well. With properties you can copy an object or set the object to be reatined. When copying objects, if large like imges or movies, the memory can grow quite large quite quickly. The concern I have over properties is everyone trying to copy things around, espeically those new to Objective C and not being aware of pre 2.0 memory management. I have to study the garbage collection but i believe its happening on message loops (like autorelease) so if you are dealing with alot of objects being passed around from object to object you can hit the issue.
As far as garbage collection comming from a .NET world where collection is not very agressive, i have seen graphics apps or video apps be very very large in memory when using managed code. But i am glad to say my tests haven't shown it show far with apples implementation. It appears the garbage collection works well. So my garbage collection comment may have been wrong. However the use improper use of copying large objects around with properties does concern me. I know the use or retain for properties of objects, even with garbage collection, appears to be more efficient than copy. I think copy works better for non managed objects (C++ and C variables).
by Scott Andrew — Sep 27
As far as garbage collection comming from a .NET world where collection is not very agressive, i have seen graphics apps or video apps be very very large in memory when using managed code. But i am glad to say my tests haven't shown it show far with apples implementation. It appears the garbage collection works well. So my garbage collection comment may have been wrong. However the use improper use of copying large objects around with properties does concern me. I know the use or retain for properties of objects, even with garbage collection, appears to be more efficient than copy. I think copy works better for non managed objects (C++ and C variables).