rust/tests/ui/allocator/custom.rs
2024-02-16 20:02:50 +00:00

60 lines
1.6 KiB
Rust

//@ run-pass
//@ aux-build:helper.rs
//@ no-prefer-dynamic
#![feature(allocator_api)]
#![feature(slice_ptr_get)]
extern crate helper;
use std::alloc::{self, Allocator, Global, Layout, System};
use std::sync::atomic::{AtomicUsize, Ordering};
static HITS: AtomicUsize = AtomicUsize::new(0);
struct A;
unsafe impl alloc::GlobalAlloc for A {
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
HITS.fetch_add(1, Ordering::SeqCst);
alloc::GlobalAlloc::alloc(&System, layout)
}
unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
HITS.fetch_add(1, Ordering::SeqCst);
alloc::GlobalAlloc::dealloc(&System, ptr, layout)
}
}
#[global_allocator]
static GLOBAL: A = A;
fn main() {
println!("hello!");
let n = HITS.load(Ordering::SeqCst);
assert!(n > 0);
unsafe {
let layout = Layout::from_size_align(4, 2).unwrap();
let memory = Global.allocate(layout.clone()).unwrap();
helper::work_with(&memory);
assert_eq!(HITS.load(Ordering::SeqCst), n + 1);
Global.deallocate(memory.as_non_null_ptr(), layout);
assert_eq!(HITS.load(Ordering::SeqCst), n + 2);
let s = String::with_capacity(10);
helper::work_with(&s);
assert_eq!(HITS.load(Ordering::SeqCst), n + 3);
drop(s);
assert_eq!(HITS.load(Ordering::SeqCst), n + 4);
let memory = System.allocate(layout.clone()).unwrap();
helper::work_with(&memory);
assert_eq!(HITS.load(Ordering::SeqCst), n + 4);
System.deallocate(memory.as_non_null_ptr(), layout);
assert_eq!(HITS.load(Ordering::SeqCst), n + 4);
}
}