On Thu, Aug 1, 2024 at 2:27 PM Danilo Krummrich <dakr@xxxxxxxxxx> wrote:
>
> On Thu, Aug 01, 2024 at 10:19:41AM +0200, Alice Ryhl wrote:
> > On Thu, Aug 1, 2024 at 2:07 AM Danilo Krummrich <dakr@xxxxxxxxxx> wrote:
> > > + /// Free an existing memory allocation.
> > > + ///
> > > + /// # Safety
> > > + ///
> > > + /// `ptr` must point to an existing and valid memory allocation created by this `Allocator`
> > > + /// instance.
> > > + unsafe fn free(ptr: NonNull<u8>) {
> > > + // SAFETY: `ptr` is guaranteed to be previously allocated with this `Allocator` or NULL.
> > > + // Calling `realloc` with a buffer size of zero, frees the buffer `ptr` points to.
> > > + let _ = unsafe { Self::realloc(Some(ptr), Layout::new::<()>(), Flags(0)) };
> > > + }
> >
> > At the very least, the provided implementation of `free` changes the
> > alignment when it calls `realloc`.
>
> Yes, I think that's fine though. Hopefully no one attempts to use the memory
> anymore once `free` is being called.
Sure, but if you require the alignment to remain constant throughout
calls to realloc, then you have to word it in a way that allows a
different alignment when the new size is zero.
Alice
