Forbid singleton allocations from shrinking their block offset

This commit is contained in:
Feoramund
2024-05-28 19:49:56 -04:00
parent 1afc235359
commit eadfbb1318

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@@ -155,7 +155,11 @@ rb_resize :: proc(stack: ^Rollback_Stack, ptr: rawptr, old_size, size, alignment
assert(block.offset >= cast(uintptr)old_size, "Rollback Stack Allocator received invalid `old_size`.")
if block.offset + cast(uintptr)size - cast(uintptr)old_size < cast(uintptr)len(block.buffer) {
block.offset += cast(uintptr)size - cast(uintptr)old_size
// Prevent singleton allocations from fragmenting by forbidding
// them to shrink, removing the possibility of overflow bugs.
if len(block.buffer) <= stack.block_size {
block.offset += cast(uintptr)size - cast(uintptr)old_size
}
#no_bounds_check return (cast([^]byte)ptr)[:size], nil
}
}