Files
RedBear-OS/src/platform/allocator/mod.rs
T
2026-01-04 02:15:29 +07:00

107 lines
2.8 KiB
Rust

use core::{
alloc::{GlobalAlloc, Layout},
cell::SyncUnsafeCell,
cmp,
mem::align_of,
ptr::{copy_nonoverlapping, write_bytes},
};
mod sys;
use super::types::*;
use crate::{ALLOCATOR, sync::Mutex};
use dlmalloc::DlmallocCApi;
pub type Dlmalloc = DlmallocCApi<sys::System>;
pub const NEWALLOCATOR: Allocator = Allocator::new();
pub struct Allocator(SyncUnsafeCell<Mutex<Dlmalloc>>);
impl Allocator {
pub const fn new() -> Self {
Allocator(SyncUnsafeCell::new(Mutex::new(Dlmalloc::new(
sys::System::new(),
))))
}
pub fn get(&self) -> *mut Mutex<Dlmalloc> {
self.0.get()
}
}
unsafe impl GlobalAlloc for Allocator {
#[inline]
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
if layout.align() <= align_of::<max_align_t>() {
(*self.get()).lock().malloc(layout.size())
} else {
(*self.get()).lock().memalign(layout.align(), layout.size())
}
}
#[inline]
unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
(*self.get()).lock().free(ptr)
}
#[inline]
unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
let ptr = self.alloc(layout);
if !ptr.is_null() && (*self.get()).lock().calloc_must_clear(ptr) {
write_bytes(ptr, 0, layout.size());
}
ptr
}
#[inline]
unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
if layout.align() <= align_of::<max_align_t>() {
(*self.get()).lock().realloc(ptr, new_size)
} else {
let new = self.alloc(Layout::from_size_align_unchecked(new_size, layout.align()));
let old_size = layout.size();
let old_align = layout.align();
if !new.is_null() {
let size = cmp::min(old_size, new_size);
copy_nonoverlapping(ptr, new, size);
}
drop((old_size, old_align));
(*self.get()).lock().free(ptr);
new
}
}
}
pub unsafe fn alloc(size: size_t) -> *mut c_void {
(*ALLOCATOR.get()).lock().malloc(size).cast()
}
pub unsafe fn alloc_align(size: size_t, alignment: size_t) -> *mut c_void {
(*ALLOCATOR.get()).lock().memalign(alignment, size).cast()
}
pub unsafe fn realloc(ptr: *mut c_void, size: size_t) -> *mut c_void {
if ptr.is_null() {
(*ALLOCATOR.get()).lock().malloc(size).cast()
} else {
(*ALLOCATOR.get()).lock().realloc(ptr.cast(), size).cast()
}
}
pub unsafe fn free(ptr: *mut c_void) {
if ptr.is_null() {
return;
}
(*ALLOCATOR.get()).lock().free(ptr.cast())
}
pub unsafe fn alloc_usable_size(ptr: *mut c_void) -> size_t {
if ptr.is_null() {
return 0;
}
(*ALLOCATOR.get()).lock().usable_size(ptr.cast())
}