Fix bug where AttachmentImages can't be used in multiple descriptor sets at the same time

[faulesocke]

This fixes #1557 It seems to work just fine with all the tests I did.

• Ran cargo fmt on the changes

[Rua]

A layout transition is a write operation, which means that concurrent access to the same image should not be allowed. Pipeline barriers protect against access on the same queue, but not another queue. The change you propose would introduce a data race if the image is concurrently accessed by another queue.

The lock_submit and check_image_access functions further down rely on the exclusive value to provide the correct locking for the image. If exclusive is false, then this locks the image only for reading, which allows a command buffer on another queue to be executed and access this image concurrently, without the insertion of a semaphore. If the first queue is actually writing to the image at that time, that's a synchronisation error.

[faulesocke]

Oh. I wasn't aware that the exclusive flag is being used for cross-command buffer dependencies. I will think of a different fix.

[Eliah-Lakhin]

@faulesocke Please ping me when it's ready for the final review. Thanks!

[Eliah-Lakhin]

@faulesocke Any updates regarding this PR?

[faulesocke]

@Eliah-Lakhin sorry I haven't had time for this and probably won't have time for another month or two.

[vE5li]

Is there any update on this?

[vE5li]

@fayalalebrun Does the commit a03cfa0 mean this can be closed?

[fayalalebrun]

@vE5li No, that's for a fork of Vulkano and doesn't address the underlying issue.

[vE5li]

Ah, my bad :)