Skip to content

Commit

Permalink
Rollup merge of #76993 - blitzerr:alloc-ref, r=Amanieu
Browse files Browse the repository at this point in the history
Changing the alloc() to accept &self instead of &mut self

Fixes: [#55](rust-lang/wg-allocators#55)

This is the first cut. It only makes the change for `alloc` method.
  • Loading branch information
Dylan-DPC authored Sep 23, 2020
2 parents eaaf5d7 + 2b19b14 commit a40d79c
Show file tree
Hide file tree
Showing 7 changed files with 48 additions and 46 deletions.
16 changes: 8 additions & 8 deletions library/alloc/src/alloc.rs
Original file line number Diff line number Diff line change
Expand Up @@ -145,7 +145,7 @@ pub unsafe fn alloc_zeroed(layout: Layout) -> *mut u8 {

impl Global {
#[inline]
fn alloc_impl(&mut self, layout: Layout, zeroed: bool) -> Result<NonNull<[u8]>, AllocErr> {
fn alloc_impl(&self, layout: Layout, zeroed: bool) -> Result<NonNull<[u8]>, AllocErr> {
match layout.size() {
0 => Ok(NonNull::slice_from_raw_parts(layout.dangling(), 0)),
// SAFETY: `layout` is non-zero in size,
Expand All @@ -160,7 +160,7 @@ impl Global {
// SAFETY: Same as `AllocRef::grow`
#[inline]
unsafe fn grow_impl(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand Down Expand Up @@ -208,17 +208,17 @@ impl Global {
#[unstable(feature = "allocator_api", issue = "32838")]
unsafe impl AllocRef for Global {
#[inline]
fn alloc(&mut self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
fn alloc(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
self.alloc_impl(layout, false)
}

#[inline]
fn alloc_zeroed(&mut self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
fn alloc_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
self.alloc_impl(layout, true)
}

#[inline]
unsafe fn dealloc(&mut self, ptr: NonNull<u8>, layout: Layout) {
unsafe fn dealloc(&self, ptr: NonNull<u8>, layout: Layout) {
if layout.size() != 0 {
// SAFETY: `layout` is non-zero in size,
// other conditions must be upheld by the caller
Expand All @@ -228,7 +228,7 @@ unsafe impl AllocRef for Global {

#[inline]
unsafe fn grow(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand All @@ -239,7 +239,7 @@ unsafe impl AllocRef for Global {

#[inline]
unsafe fn grow_zeroed(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand All @@ -250,7 +250,7 @@ unsafe impl AllocRef for Global {

#[inline]
unsafe fn shrink(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand Down
2 changes: 1 addition & 1 deletion library/alloc/src/raw_vec.rs
Original file line number Diff line number Diff line change
Expand Up @@ -170,7 +170,7 @@ impl<T, A: AllocRef> RawVec<T, A> {
Self::allocate_in(capacity, AllocInit::Zeroed, alloc)
}

fn allocate_in(capacity: usize, init: AllocInit, mut alloc: A) -> Self {
fn allocate_in(capacity: usize, init: AllocInit, alloc: A) -> Self {
if mem::size_of::<T>() == 0 {
Self::new_in(alloc)
} else {
Expand Down
17 changes: 9 additions & 8 deletions library/alloc/src/raw_vec/tests.rs
Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
use super::*;
use std::cell::Cell;

#[test]
fn allocator_param() {
Expand All @@ -17,32 +18,32 @@ fn allocator_param() {
// A dumb allocator that consumes a fixed amount of fuel
// before allocation attempts start failing.
struct BoundedAlloc {
fuel: usize,
fuel: Cell<usize>,
}
unsafe impl AllocRef for BoundedAlloc {
fn alloc(&mut self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
fn alloc(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
let size = layout.size();
if size > self.fuel {
if size > self.fuel.get() {
return Err(AllocErr);
}
match Global.alloc(layout) {
ok @ Ok(_) => {
self.fuel -= size;
self.fuel.set(self.fuel.get() - size);
ok
}
err @ Err(_) => err,
}
}
unsafe fn dealloc(&mut self, ptr: NonNull<u8>, layout: Layout) {
unsafe fn dealloc(&self, ptr: NonNull<u8>, layout: Layout) {
unsafe { Global.dealloc(ptr, layout) }
}
}

let a = BoundedAlloc { fuel: 500 };
let a = BoundedAlloc { fuel: Cell::new(500) };
let mut v: RawVec<u8, _> = RawVec::with_capacity_in(50, a);
assert_eq!(v.alloc.fuel, 450);
assert_eq!(v.alloc.fuel.get(), 450);
v.reserve(50, 150); // (causes a realloc, thus using 50 + 150 = 200 units of fuel)
assert_eq!(v.alloc.fuel, 250);
assert_eq!(v.alloc.fuel.get(), 250);
}

#[test]
Expand Down
2 changes: 1 addition & 1 deletion library/alloc/tests/heap.rs
Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@ fn std_heap_overaligned_request() {
check_overalign_requests(Global)
}

fn check_overalign_requests<T: AllocRef>(mut allocator: T) {
fn check_overalign_requests<T: AllocRef>(allocator: T) {
for &align in &[4, 8, 16, 32] {
// less than and bigger than `MIN_ALIGN`
for &size in &[align / 2, align - 1] {
Expand Down
28 changes: 14 additions & 14 deletions library/core/src/alloc/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -109,7 +109,7 @@ pub unsafe trait AllocRef {
/// call the [`handle_alloc_error`] function, rather than directly invoking `panic!` or similar.
///
/// [`handle_alloc_error`]: ../../alloc/alloc/fn.handle_alloc_error.html
fn alloc(&mut self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr>;
fn alloc(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr>;

/// Behaves like `alloc`, but also ensures that the returned memory is zero-initialized.
///
Expand All @@ -126,7 +126,7 @@ pub unsafe trait AllocRef {
/// call the [`handle_alloc_error`] function, rather than directly invoking `panic!` or similar.
///
/// [`handle_alloc_error`]: ../../alloc/alloc/fn.handle_alloc_error.html
fn alloc_zeroed(&mut self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
fn alloc_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
let ptr = self.alloc(layout)?;
// SAFETY: `alloc` returns a valid memory block
unsafe { ptr.as_non_null_ptr().as_ptr().write_bytes(0, ptr.len()) }
Expand All @@ -142,7 +142,7 @@ pub unsafe trait AllocRef {
///
/// [*currently allocated*]: #currently-allocated-memory
/// [*fit*]: #memory-fitting
unsafe fn dealloc(&mut self, ptr: NonNull<u8>, layout: Layout);
unsafe fn dealloc(&self, ptr: NonNull<u8>, layout: Layout);

/// Attempts to extend the memory block.
///
Expand Down Expand Up @@ -183,7 +183,7 @@ pub unsafe trait AllocRef {
///
/// [`handle_alloc_error`]: ../../alloc/alloc/fn.handle_alloc_error.html
unsafe fn grow(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand Down Expand Up @@ -244,7 +244,7 @@ pub unsafe trait AllocRef {
///
/// [`handle_alloc_error`]: ../../alloc/alloc/fn.handle_alloc_error.html
unsafe fn grow_zeroed(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand Down Expand Up @@ -308,7 +308,7 @@ pub unsafe trait AllocRef {
///
/// [`handle_alloc_error`]: ../../alloc/alloc/fn.handle_alloc_error.html
unsafe fn shrink(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand Down Expand Up @@ -337,35 +337,35 @@ pub unsafe trait AllocRef {
///
/// The returned adaptor also implements `AllocRef` and will simply borrow this.
#[inline(always)]
fn by_ref(&mut self) -> &mut Self {
fn by_ref(&mut self) -> &Self {
self
}
}

#[unstable(feature = "allocator_api", issue = "32838")]
unsafe impl<A> AllocRef for &mut A
unsafe impl<A> AllocRef for &A
where
A: AllocRef + ?Sized,
{
#[inline]
fn alloc(&mut self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
fn alloc(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
(**self).alloc(layout)
}

#[inline]
fn alloc_zeroed(&mut self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
fn alloc_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
(**self).alloc_zeroed(layout)
}

#[inline]
unsafe fn dealloc(&mut self, ptr: NonNull<u8>, layout: Layout) {
unsafe fn dealloc(&self, ptr: NonNull<u8>, layout: Layout) {
// SAFETY: the safety contract must be upheld by the caller
unsafe { (**self).dealloc(ptr, layout) }
}

#[inline]
unsafe fn grow(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand All @@ -376,7 +376,7 @@ where

#[inline]
unsafe fn grow_zeroed(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand All @@ -387,7 +387,7 @@ where

#[inline]
unsafe fn shrink(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand Down
24 changes: 12 additions & 12 deletions library/std/src/alloc.rs
Original file line number Diff line number Diff line change
Expand Up @@ -133,7 +133,7 @@ pub struct System;

impl System {
#[inline]
fn alloc_impl(&mut self, layout: Layout, zeroed: bool) -> Result<NonNull<[u8]>, AllocErr> {
fn alloc_impl(&self, layout: Layout, zeroed: bool) -> Result<NonNull<[u8]>, AllocErr> {
match layout.size() {
0 => Ok(NonNull::slice_from_raw_parts(layout.dangling(), 0)),
// SAFETY: `layout` is non-zero in size,
Expand All @@ -152,7 +152,7 @@ impl System {
// SAFETY: Same as `AllocRef::grow`
#[inline]
unsafe fn grow_impl(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand Down Expand Up @@ -190,7 +190,7 @@ impl System {
old_size => unsafe {
let new_ptr = self.alloc_impl(new_layout, zeroed)?;
ptr::copy_nonoverlapping(ptr.as_ptr(), new_ptr.as_mut_ptr(), old_size);
self.dealloc(ptr, old_layout);
AllocRef::dealloc(&self, ptr, old_layout);
Ok(new_ptr)
},
}
Expand All @@ -202,17 +202,17 @@ impl System {
#[unstable(feature = "allocator_api", issue = "32838")]
unsafe impl AllocRef for System {
#[inline]
fn alloc(&mut self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
fn alloc(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
self.alloc_impl(layout, false)
}

#[inline]
fn alloc_zeroed(&mut self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
fn alloc_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
self.alloc_impl(layout, true)
}

#[inline]
unsafe fn dealloc(&mut self, ptr: NonNull<u8>, layout: Layout) {
unsafe fn dealloc(&self, ptr: NonNull<u8>, layout: Layout) {
if layout.size() != 0 {
// SAFETY: `layout` is non-zero in size,
// other conditions must be upheld by the caller
Expand All @@ -222,7 +222,7 @@ unsafe impl AllocRef for System {

#[inline]
unsafe fn grow(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand All @@ -233,7 +233,7 @@ unsafe impl AllocRef for System {

#[inline]
unsafe fn grow_zeroed(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand All @@ -244,7 +244,7 @@ unsafe impl AllocRef for System {

#[inline]
unsafe fn shrink(
&mut self,
&self,
ptr: NonNull<u8>,
old_layout: Layout,
new_layout: Layout,
Expand All @@ -257,7 +257,7 @@ unsafe impl AllocRef for System {
match new_layout.size() {
// SAFETY: conditions must be upheld by the caller
0 => unsafe {
self.dealloc(ptr, old_layout);
AllocRef::dealloc(&self, ptr, old_layout);
Ok(NonNull::slice_from_raw_parts(new_layout.dangling(), 0))
},

Expand All @@ -277,9 +277,9 @@ unsafe impl AllocRef for System {
// `new_ptr`. Thus, the call to `copy_nonoverlapping` is safe. The safety contract
// for `dealloc` must be upheld by the caller.
new_size => unsafe {
let new_ptr = self.alloc(new_layout)?;
let new_ptr = AllocRef::alloc(&self, new_layout)?;
ptr::copy_nonoverlapping(ptr.as_ptr(), new_ptr.as_mut_ptr(), new_size);
self.dealloc(ptr, old_layout);
AllocRef::dealloc(&self, ptr, old_layout);
Ok(new_ptr)
},
}
Expand Down
5 changes: 3 additions & 2 deletions src/test/ui/allocator/custom.rs
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@ extern crate helper;

use std::alloc::{self, AllocRef, Global, Layout, System};
use std::sync::atomic::{AtomicUsize, Ordering};
use std::ptr::NonNull;

static HITS: AtomicUsize = AtomicUsize::new(0);

Expand All @@ -18,12 +19,12 @@ struct A;
unsafe impl alloc::GlobalAlloc for A {
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
HITS.fetch_add(1, Ordering::SeqCst);
System.alloc(layout)
alloc::GlobalAlloc::alloc(&System, layout)
}

unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
HITS.fetch_add(1, Ordering::SeqCst);
System.dealloc(ptr, layout)
AllocRef::dealloc(&System, NonNull::new(ptr).unwrap(), layout)
}
}

Expand Down

0 comments on commit a40d79c

Please sign in to comment.