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Philipp Oppermann
2019-06-17 13:23:39 +02:00
parent 398ca5357c
commit 1eb8f0f2c7
1 changed files with 14 additions and 5 deletions
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19
src/memory/allocator/bucket.rs
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@@ -2,6 +2,7 @@ use super::MutGlobalAlloc;
use core::alloc::Layout;
use core::mem::size_of;
use core::fmt::{self, Debug};
use core::cmp;
#[derive(Debug)]
pub struct BucketAllocator<A> where A: MutGlobalAlloc + Debug {
@@ -45,6 +46,10 @@ impl Bucket {
head: None,
}
}
fn layout(&self) -> Layout {
Layout::from_size_align(self.size, self.size).unwrap()
}
}
impl fmt::Debug for Bucket {
@@ -82,8 +87,9 @@ impl Region {
}
impl<A> BucketAllocator<A> where A: MutGlobalAlloc + Debug {
fn get_bucket_index(&self, size: usize) -> Option<usize> {
match self.buckets.binary_search_by(|bucket| bucket.size.cmp(&size)) {
fn get_bucket_index(&self, layout: &Layout) -> Option<usize> {
let required_bucket_size = cmp::max(layout.size(), layout.align());
match self.buckets.binary_search_by(|bucket| bucket.size.cmp(&required_bucket_size)) {
Ok(index) => Some(index),
Err(index) if index < self.buckets.len() => Some(index),
Err(_) => None,
@@ -93,19 +99,22 @@ impl<A> BucketAllocator<A> where A: MutGlobalAlloc + Debug {
impl<A> MutGlobalAlloc for BucketAllocator<A> where A: MutGlobalAlloc + Debug {
fn alloc(&mut self, layout: Layout) -> *mut u8 {
if let Some(bucket_index) = self.get_bucket_index(layout.size()) {
if let Some(bucket_index) = self.get_bucket_index(&layout) {
let bucket = &mut self.buckets[bucket_index];
if let Some(head) = bucket.head.take() {
let next = head.next.take();
bucket.head = next;
return head.as_mut_u8();
} else {
self.underlying.alloc(bucket.layout())
}
} else {
self.underlying.alloc(layout)
}
self.underlying.alloc(layout)
}
fn dealloc(&mut self, ptr: *mut u8, layout: Layout) {
if let Some(bucket_index) = self.get_bucket_index(layout.size()) {
if let Some(bucket_index) = self.get_bucket_index(&layout) {
let bucket = &mut self.buckets[bucket_index];
let region = unsafe {Region::from_mut_u8(ptr)};
region.next = bucket.head.take();