1 #![feature(allocator_api, slice_ptr_get)]
3 use std::alloc::{Allocator, Global, Layout, System};
7 fn check_alloc<T: Allocator>(allocator: T) {
9 for &align in &[4, 8, 16, 32] {
10 let layout_20 = Layout::from_size_align(20, align).unwrap();
11 let layout_40 = Layout::from_size_align(40, 4 * align).unwrap();
12 let layout_10 = Layout::from_size_align(10, align / 2).unwrap();
15 let a = allocator.allocate(layout_20).unwrap().as_non_null_ptr();
17 a.as_ptr() as usize % layout_20.align(),
19 "pointer is incorrectly aligned",
21 allocator.deallocate(a, layout_20);
24 let p1 = allocator.allocate_zeroed(layout_20).unwrap().as_non_null_ptr();
26 p1.as_ptr() as usize % layout_20.align(),
28 "pointer is incorrectly aligned",
30 assert_eq!(*p1.as_ptr(), 0);
32 // old size < new size
33 let p2 = allocator.grow(p1, layout_20, layout_40).unwrap().as_non_null_ptr();
35 p2.as_ptr() as usize % layout_40.align(),
37 "pointer is incorrectly aligned",
39 let slice = slice::from_raw_parts(p2.as_ptr(), 20);
40 assert_eq!(&slice, &[0_u8; 20]);
42 // old size == new size
43 let p3 = allocator.grow(p2, layout_40, layout_40).unwrap().as_non_null_ptr();
45 p3.as_ptr() as usize % layout_40.align(),
47 "pointer is incorrectly aligned",
49 let slice = slice::from_raw_parts(p3.as_ptr(), 20);
50 assert_eq!(&slice, &[0_u8; 20]);
52 // old size > new size
53 let p4 = allocator.shrink(p3, layout_40, layout_10).unwrap().as_non_null_ptr();
55 p4.as_ptr() as usize % layout_10.align(),
57 "pointer is incorrectly aligned",
59 let slice = slice::from_raw_parts(p4.as_ptr(), 10);
60 assert_eq!(&slice, &[0_u8; 10]);
62 allocator.deallocate(p4, layout_10);
67 fn check_align_requests<T: Allocator>(allocator: T) {
68 #[rustfmt::skip] // https://github.com/rust-lang/rustfmt/issues/3255
69 for &size in &[2, 8, 64] { // size less than and bigger than alignment
70 for &align in &[4, 8, 16, 32] { // Be sure to cover less than and bigger than `MIN_ALIGN` for all architectures
73 let pointers: Vec<_> = (0..iterations)
76 .allocate(Layout::from_size_align(size, align).unwrap())
81 for &ptr in &pointers {
83 (ptr.as_ptr() as usize) % align,
85 "Got a pointer less aligned than requested",
90 for &ptr in &pointers {
91 allocator.deallocate(ptr, Layout::from_size_align(size, align).unwrap())
100 let l = Layout::new::<T>();
101 // allocate manually with global allocator, then turn into Box and free there
103 let ptr = Global.allocate(l).unwrap().as_non_null_ptr().as_ptr() as *mut T;
104 let b = Box::from_raw(ptr);
111 let l = Layout::new::<T>();
112 // allocate with the Box, then deallocate manually with global allocator
114 let b = Box::new(T::default());
115 let ptr = Box::into_raw(b);
116 Global.deallocate(NonNull::new(ptr as *mut u8).unwrap(), l);
123 check_align_requests(System);
124 check_align_requests(Global);