How to use destroy and free.

[forkit]

On Wednesday, 4 May 2022 at 15:04:13 UTC, cc wrote:
> The MemUtils package offers a `ScopedPool` utility that seems 
> interesting.  It isn't well documented however so I have no 
> idea if it actually works like I expect.  I presume this would 
> work something akin to a VM memory snapshot/rollback for the 
> GC?  It would be pretty handy for some scenarios, say a 
> serialization library.  You specify a snapshot point (add a 
> pool to the stack?), incur all your GC allocations necessary 
> for generating the structure of your serialized data (which go 
> into the pool instead of the GC proper?), then you write it to 
> disk and pop the stack, effectively rolling back to the 
> original memory state of your program's GC.  As long as you 
> make sure not to leak anything allocated within that phase, 
> seems like a good deal.
>
> https://code.dlang.org/packages/memutils

Interesting.

My idea was ... objects marked as 'inscope' would be GC allocated 
in a LIFO region of the heap, rather than the general GC pool.

Explicately deallocating such objects at end of scope then 
becomes a no brainer for the GC (since 'inscope' would ensure at 
compile time that no pointers/aliasing outside of that scope 
could exist).

The LIFO would also avoid the problem of fragmentation (i.e. if 
the objects were allocated in the general GC pool instead of a 
separate pool).

This would give the programmer 'scope-based deallocation of GC 
allocated memory'.