sel4_abstract_allocator/
bump.rs

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1//
2// Copyright 2023, Colias Group, LLC
3//
4// SPDX-License-Identifier: BSD-2-Clause
5//
6
7use core::alloc::Layout;
8use core::ops::Range;
9
10use crate::{AbstractAllocator, AbstractAllocatorAllocation};
11
12pub struct BumpAllocator {
13    watermark: usize,
14    size: usize,
15}
16
17impl BumpAllocator {
18    pub fn new(size: usize) -> Self {
19        Self { watermark: 0, size }
20    }
21}
22
23impl AbstractAllocator for BumpAllocator {
24    type AllocationError = InsufficientResources;
25
26    type Allocation = Allocation;
27
28    fn allocate(&mut self, layout: Layout) -> Result<Self::Allocation, Self::AllocationError> {
29        let start = self.watermark.next_multiple_of(layout.align());
30        let end = start + layout.size();
31        if end > self.size {
32            return Err(InsufficientResources::new());
33        }
34        self.watermark = end;
35        Ok(Allocation::new(start..end))
36    }
37
38    fn deallocate(&mut self, _allocation: Self::Allocation) {}
39}
40
41pub struct Allocation(Range<usize>);
42
43impl Allocation {
44    fn new(range: Range<usize>) -> Self {
45        Self(range)
46    }
47}
48
49impl AbstractAllocatorAllocation for Allocation {
50    fn range(&self) -> Range<usize> {
51        self.0.clone()
52    }
53}
54
55#[derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
56pub struct InsufficientResources(());
57
58impl InsufficientResources {
59    fn new() -> Self {
60        Self(())
61    }
62}
sel4_abstract_allocator/bump.rs

sel4_abstract_allocator/
bump.rs
