rust/tests/run-pass/heap_allocator.rs

55 lines
1.6 KiB
Rust

//ignore-windows: Inspects allocation base address on Windows
#![feature(allocator_api)]
use std::ptr::NonNull;
use std::alloc::{Global, Alloc, Layout, System};
fn check_overalign_requests<T: Alloc>(mut allocator: T) {
let size = 8;
let align = 16; // greater than size
let iterations = 1; // Miri is deterministic, no need to try many times
unsafe {
let pointers: Vec<_> = (0..iterations).map(|_| {
allocator.alloc(Layout::from_size_align(size, align).unwrap()).unwrap()
}).collect();
for &ptr in &pointers {
assert_eq!((ptr.as_ptr() as usize) % align, 0,
"Got a pointer less aligned than requested")
}
// Clean up
for &ptr in &pointers {
allocator.dealloc(ptr, Layout::from_size_align(size, align).unwrap())
}
}
}
fn global_to_box() {
type T = [i32; 4];
let l = Layout::new::<T>();
// allocate manually with global allocator, then turn into Box and free there
unsafe {
let ptr = Global.alloc(l).unwrap().as_ptr() as *mut T;
let b = Box::from_raw(ptr);
drop(b);
}
}
fn box_to_global() {
type T = [i32; 4];
let l = Layout::new::<T>();
// allocate with the Box, then deallocate manually with global allocator
unsafe {
let b = Box::new(T::default());
let ptr = Box::into_raw(b);
Global.dealloc(NonNull::new(ptr as *mut u8).unwrap(), l);
}
}
fn main() {
check_overalign_requests(System);
check_overalign_requests(Global);
global_to_box();
box_to_global();
}