210 lines
8.0 KiB
Rust
210 lines
8.0 KiB
Rust
// SPDX-License-Identifier: MIT OR Apache-2.0
|
|
// SPDX-FileCopyrightText: The Rust Project Developers (see https://thanks.rust-lang.org)
|
|
|
|
#![no_std]
|
|
#![feature(allocator_api, rustc_private)]
|
|
#![cfg_attr(any(unix, target_os = "redox"), feature(libc))]
|
|
|
|
// The minimum alignment guaranteed by the architecture. This value is used to
|
|
// add fast paths for low alignment values.
|
|
#[cfg(any(target_arch = "x86",
|
|
target_arch = "arm",
|
|
target_arch = "mips",
|
|
target_arch = "mips32r6",
|
|
target_arch = "powerpc",
|
|
target_arch = "powerpc64"))]
|
|
const MIN_ALIGN: usize = 8;
|
|
#[cfg(any(target_arch = "x86_64",
|
|
target_arch = "aarch64",
|
|
target_arch = "loongarch64",
|
|
target_arch = "mips64",
|
|
target_arch = "mips64r6",
|
|
target_arch = "s390x",
|
|
target_arch = "sparc64"))]
|
|
const MIN_ALIGN: usize = 16;
|
|
|
|
pub struct System;
|
|
#[cfg(any(windows, unix, target_os = "redox"))]
|
|
mod realloc_fallback {
|
|
use core::alloc::{GlobalAlloc, Layout};
|
|
use core::cmp;
|
|
use core::ptr;
|
|
impl super::System {
|
|
pub(crate) unsafe fn realloc_fallback(&self, ptr: *mut u8, old_layout: Layout,
|
|
new_size: usize) -> *mut u8 {
|
|
// Docs for GlobalAlloc::realloc require this to be valid:
|
|
let new_layout = Layout::from_size_align_unchecked(new_size, old_layout.align());
|
|
let new_ptr = GlobalAlloc::alloc(self, new_layout);
|
|
if !new_ptr.is_null() {
|
|
let size = cmp::min(old_layout.size(), new_size);
|
|
ptr::copy_nonoverlapping(ptr, new_ptr, size);
|
|
GlobalAlloc::dealloc(self, ptr, old_layout);
|
|
}
|
|
new_ptr
|
|
}
|
|
}
|
|
}
|
|
#[cfg(any(unix, target_os = "redox"))]
|
|
mod platform {
|
|
extern crate libc;
|
|
use core::ptr;
|
|
use MIN_ALIGN;
|
|
use System;
|
|
use core::alloc::{GlobalAlloc, Layout};
|
|
unsafe impl GlobalAlloc for System {
|
|
#[inline]
|
|
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
|
|
if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() {
|
|
libc::malloc(layout.size()) as *mut u8
|
|
} else {
|
|
#[cfg(target_os = "macos")]
|
|
{
|
|
if layout.align() > (1 << 31) {
|
|
return ptr::null_mut()
|
|
}
|
|
}
|
|
aligned_malloc(&layout)
|
|
}
|
|
}
|
|
#[inline]
|
|
unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
|
|
if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() {
|
|
libc::calloc(layout.size(), 1) as *mut u8
|
|
} else {
|
|
let ptr = self.alloc(layout.clone());
|
|
if !ptr.is_null() {
|
|
ptr::write_bytes(ptr, 0, layout.size());
|
|
}
|
|
ptr
|
|
}
|
|
}
|
|
#[inline]
|
|
unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
|
|
libc::free(ptr as *mut libc::c_void)
|
|
}
|
|
#[inline]
|
|
unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
|
|
if layout.align() <= MIN_ALIGN && layout.align() <= new_size {
|
|
libc::realloc(ptr as *mut libc::c_void, new_size) as *mut u8
|
|
} else {
|
|
self.realloc_fallback(ptr, layout, new_size)
|
|
}
|
|
}
|
|
}
|
|
#[cfg(any(target_os = "android",
|
|
target_os = "hermit",
|
|
target_os = "redox",
|
|
target_os = "solaris"))]
|
|
#[inline]
|
|
unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
|
|
// On android we currently target API level 9 which unfortunately
|
|
// doesn't have the `posix_memalign` API used below. Instead we use
|
|
// `memalign`, but this unfortunately has the property on some systems
|
|
// where the memory returned cannot be deallocated by `free`!
|
|
//
|
|
// Upon closer inspection, however, this appears to work just fine with
|
|
// Android, so for this platform we should be fine to call `memalign`
|
|
// (which is present in API level 9). Some helpful references could
|
|
// possibly be chromium using memalign [1], attempts at documenting that
|
|
// memalign + free is ok [2] [3], or the current source of chromium
|
|
// which still uses memalign on android [4].
|
|
//
|
|
// [1]: https://codereview.chromium.org/10796020/
|
|
// [2]: https://code.google.com/p/android/issues/detail?id=35391
|
|
// [3]: https://bugs.chromium.org/p/chromium/issues/detail?id=138579
|
|
// [4]: https://chromium.googlesource.com/chromium/src/base/+/master/
|
|
// /memory/aligned_memory.cc
|
|
libc::memalign(layout.align(), layout.size()) as *mut u8
|
|
}
|
|
#[cfg(not(any(target_os = "android",
|
|
target_os = "hermit",
|
|
target_os = "redox",
|
|
target_os = "solaris")))]
|
|
#[inline]
|
|
unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
|
|
let mut out = ptr::null_mut();
|
|
let ret = libc::posix_memalign(&mut out, layout.align(), layout.size());
|
|
if ret != 0 {
|
|
ptr::null_mut()
|
|
} else {
|
|
out as *mut u8
|
|
}
|
|
}
|
|
}
|
|
#[cfg(windows)]
|
|
#[allow(nonstandard_style)]
|
|
mod platform {
|
|
use MIN_ALIGN;
|
|
use System;
|
|
use core::alloc::{GlobalAlloc, Layout};
|
|
type LPVOID = *mut u8;
|
|
type HANDLE = LPVOID;
|
|
type SIZE_T = usize;
|
|
type DWORD = u32;
|
|
type BOOL = i32;
|
|
extern "system" {
|
|
fn GetProcessHeap() -> HANDLE;
|
|
fn HeapAlloc(hHeap: HANDLE, dwFlags: DWORD, dwBytes: SIZE_T) -> LPVOID;
|
|
fn HeapReAlloc(hHeap: HANDLE, dwFlags: DWORD, lpMem: LPVOID, dwBytes: SIZE_T) -> LPVOID;
|
|
fn HeapFree(hHeap: HANDLE, dwFlags: DWORD, lpMem: LPVOID) -> BOOL;
|
|
fn GetLastError() -> DWORD;
|
|
}
|
|
#[repr(C)]
|
|
struct Header(*mut u8);
|
|
const HEAP_ZERO_MEMORY: DWORD = 0x00000008;
|
|
unsafe fn get_header<'a>(ptr: *mut u8) -> &'a mut Header {
|
|
&mut *(ptr as *mut Header).sub(1)
|
|
}
|
|
unsafe fn align_ptr(ptr: *mut u8, align: usize) -> *mut u8 {
|
|
let aligned = ptr.add(align - (ptr as usize & (align - 1)));
|
|
*get_header(aligned) = Header(ptr);
|
|
aligned
|
|
}
|
|
#[inline]
|
|
unsafe fn allocate_with_flags(layout: Layout, flags: DWORD) -> *mut u8 {
|
|
let ptr = if layout.align() <= MIN_ALIGN {
|
|
HeapAlloc(GetProcessHeap(), flags, layout.size())
|
|
} else {
|
|
let size = layout.size() + layout.align();
|
|
let ptr = HeapAlloc(GetProcessHeap(), flags, size);
|
|
if ptr.is_null() {
|
|
ptr
|
|
} else {
|
|
align_ptr(ptr, layout.align())
|
|
}
|
|
};
|
|
ptr as *mut u8
|
|
}
|
|
unsafe impl GlobalAlloc for System {
|
|
#[inline]
|
|
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
|
|
allocate_with_flags(layout, 0)
|
|
}
|
|
#[inline]
|
|
unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
|
|
allocate_with_flags(layout, HEAP_ZERO_MEMORY)
|
|
}
|
|
#[inline]
|
|
unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
|
|
if layout.align() <= MIN_ALIGN {
|
|
let err = HeapFree(GetProcessHeap(), 0, ptr as LPVOID);
|
|
debug_assert!(err != 0, "Failed to free heap memory: {}",
|
|
GetLastError());
|
|
} else {
|
|
let header = get_header(ptr);
|
|
let err = HeapFree(GetProcessHeap(), 0, header.0 as LPVOID);
|
|
debug_assert!(err != 0, "Failed to free heap memory: {}",
|
|
GetLastError());
|
|
}
|
|
}
|
|
#[inline]
|
|
unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
|
|
if layout.align() <= MIN_ALIGN {
|
|
HeapReAlloc(GetProcessHeap(), 0, ptr as LPVOID, new_size) as *mut u8
|
|
} else {
|
|
self.realloc_fallback(ptr, layout, new_size)
|
|
}
|
|
}
|
|
}
|
|
}
|