Non-freeing GC memory management

[tcak via Digitalmars-d]

On Tuesday, 17 November 2015 at 19:32:05 UTC, Adam D. Ruppe wrote:
> On Tuesday, 17 November 2015 at 19:27:15 UTC, tcak wrote:
>> As far as I know, GC has a separate thread that stops all 
>> other threads periodically to clear the unused memory fields.
>
> That is a common misconception...
>
>> What disadvantages would we have if GC was to be freeing 
>> memory only when allocation is requested, and not checking 
>> periodically?
>
> This is what it actually does now.

That means object destructors are to be called only when a new 
allocation happens? But not all allocations end up with this. If 
this is so, this behaviour of GC encourages to call destroy (or 
was it clear?) on objects manually to manage the memory more 
efficiently.