Am 14.03.2012 17:07, schrieb Invisible:
>>> You seem to suggest that there's 16 bytes of overhead /per object/. I'm
>>> saying I'm used to there being a fixed number of bytes of overhead,
>>> regardless of the number of objects. That's O(N) vs O(1).
>>
>> That's obviously impossible. The only way to achieve that would be
>> to allocate an array of objects (by value).
>>
>> If you allocate individual objects, the allocator has to know where they
>> are and if those memory blocks are free or not. At least if the allocator
>> ever wants to reuse freed memory blocks.
>
> If you're using garbage collection, it's quite possible - and, indeed,
> usual. Each time the GC collects the garbage, it also defragments the
> free space. You therefore need only store a pointer to the next free
> byte of memory. To allocate, just increment this pointer by the size of
> the block allocated. Allocation is now O(1) in time and space.

So far, so good. But how does the GC know how long each chunk of 
garbage-to-collect is?

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