diff --git a/src/memory/heap_allocator.rs b/src/memory/heap_allocator.rs deleted file mode 100644 index cf8e6d20..00000000 --- a/src/memory/heap_allocator.rs +++ /dev/null @@ -1,66 +0,0 @@ -use alloc::heap::{Alloc, AllocErr, Layout}; - -use core::sync::atomic::{AtomicUsize, Ordering}; - -/// A simple allocator that allocates memory linearly and ignores freed memory. -#[derive(Debug)] -pub struct BumpAllocator { - heap_start: usize, - heap_end: usize, - next: AtomicUsize, -} - -impl BumpAllocator { - pub const fn new(heap_start: usize, heap_end: usize) -> Self { - Self { heap_start, heap_end, next: AtomicUsize::new(heap_start) } - } -} - -unsafe impl<'a> Alloc for &'a BumpAllocator { - unsafe fn alloc(&mut self, layout: Layout) -> Result<*mut u8, AllocErr> { - loop { - // load current state of the `next` field - let current_next = self.next.load(Ordering::Relaxed); - let alloc_start = align_up(current_next, layout.align()); - let alloc_end = alloc_start.saturating_add(layout.size()); - - if alloc_end <= self.heap_end { - // update the `next` pointer if it still has the value `current_next` - let next_now = self.next.compare_and_swap(current_next, alloc_end, - Ordering::Relaxed); - if next_now == current_next { - // next address was successfully updated, allocation succeeded - return Ok(alloc_start as *mut u8); - } - } else { - return Err(AllocErr::Exhausted{ request: layout }) - } - } - } - - unsafe fn dealloc(&mut self, ptr: *mut u8, layout: Layout) { - // do nothing, leak memory - } - - fn oom(&mut self, _: AllocErr) -> ! { - panic!("Out of memory"); - } -} - -/// Align downwards. Returns the greatest x with alignment `align` -/// so that x <= addr. The alignment must be a power of 2. -pub fn align_down(addr: usize, align: usize) -> usize { - if align.is_power_of_two() { - addr & !(align - 1) - } else if align == 0 { - addr - } else { - panic!("`align` must be a power of 2"); - } -} - -/// Align upwards. Returns the smallest x with alignment `align` -/// so that x >= addr. The alignment must be a power of 2. -pub fn align_up(addr: usize, align: usize) -> usize { - align_down(addr + align - 1, align) -}