a valid/invalid reference without accessing memory that is invalid in the mean time.
How does a GC do this? It would have the same problem?
A GC manages all memory, local variable allocation inclusive. IOW, the way a GC does it, is not possible in a mixed environment.
Are you saying it would be a managed pointer then which is allocated on the heap? (I had assumed the pointer would be on the stack and the object in the heap)
Also note that the list of references must be a dynamically size structure, incurring getmem and size-change overhead on a simple assignment.
yes a "single linked list" is a very efficient dynamically sized structure and much cheaper than try..finally or using Tlist.
It's very expensive. getmem is quite expensive, and you need it for every reference this way.
Okay then use Tlist with preallocation of say half a dozen references - that should be efficient for 99% of cases for an individual object's references.
I doubt performance would improve, specially since the edge of this problem (the worst 90%) can be taken off by simply disabling try...finally generation in places where they are unlikely to happen.
Is there a real failsafe way of doing that?
Nothing is failsafe. However e.g. in RTL string routines exceptions shouldn't occur unless memory is exhausted, in case it doesn't matter much anyway.
What about all other non string exceptions that can occur between creation and destruction of the ansistring?
Multithreaded environments too?
jamie.
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