We remove the existing `swift_reflection_iterateAsyncTaskAllocations` API that attempts to provide all necessary information about a tasks's allocations starting from the task. Instead, we split it into two pieces: `swift_reflection_asyncTaskSlabPointer` to get the first slab for a task, and `+swift_reflection_asyncTaskSlabAllocations` to get the allocations in a slab, and a pointer to the next slab.
We also add a dummy metadata pointer to the beginning of each slab. This allows tools to identify slab allocations on the heap without needing to locate every single async task object. They can then use `swift_reflection_asyncTaskSlabAllocations` on such allocations to find out about the contents.
rdar://82549631
We remove the existing `swift_reflection_iterateAsyncTaskAllocations` API that attempts to provide all necessary information about a tasks's allocations starting from the task. Instead, we split it into two pieces: `swift_reflection_asyncTaskSlabPointer` to get the first slab for a task, and `+swift_reflection_asyncTaskSlabAllocations` to get the allocations in a slab, and a pointer to the next slab.
We also add a dummy metadata pointer to the beginning of each slab. This allows tools to identify slab allocations on the heap without needing to locate every single async task object. They can then use `swift_reflection_asyncTaskSlabAllocations` on such allocations to find out about the contents.
rdar://82549631
A StackAllocator performs fast allocation and deallocation of memory by implementing a bump-pointer allocation strategy.
In contrast to a pure bump-pointer allocator, it's possible to free memory.
Allocations and deallocations must follow a strict stack discipline.
In general, slabs which become unused are _not_ freed, but reused for subsequent allocations.
The first slab can be placed into pre-allocated memory.