src/test/ui/allocator/custom.rs

   1 // run-pass
   2
   3 // aux-build:helper.rs
   4 // no-prefer-dynamic
   5
   6 #![feature(allocator_api)]
   7 #![feature(slice_ptr_get)]
   8
   9 extern crate helper;
  10
  11 use std::alloc::{self, Allocator, Global, Layout, System};
  12 use std::sync::atomic::{AtomicUsize, Ordering};
  13
  14 static HITS: AtomicUsize = AtomicUsize::new(0);
  15
  16 struct A;
  17
  18 unsafe impl alloc::GlobalAlloc for A {
  19     unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
  20         HITS.fetch_add(1, Ordering::SeqCst);
  21         alloc::GlobalAlloc::alloc(&System, layout)
  22     }
  23
  24     unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
  25         HITS.fetch_add(1, Ordering::SeqCst);
  26         alloc::GlobalAlloc::dealloc(&System, ptr, layout)
  27     }
  28 }
  29
  30 #[global_allocator]
  31 static GLOBAL: A = A;
  32
  33 fn main() {
  34     println!("hello!");
  35
  36     let n = HITS.load(Ordering::SeqCst);
  37     assert!(n > 0);
  38     unsafe {
  39         let layout = Layout::from_size_align(4, 2).unwrap();
  40
  41         let memory = Global.allocate(layout.clone()).unwrap();
  42         helper::work_with(&memory);
  43         assert_eq!(HITS.load(Ordering::SeqCst), n + 1);
  44         Global.deallocate(memory.as_non_null_ptr(), layout);
  45         assert_eq!(HITS.load(Ordering::SeqCst), n + 2);
  46
  47         let s = String::with_capacity(10);
  48         helper::work_with(&s);
  49         assert_eq!(HITS.load(Ordering::SeqCst), n + 3);
  50         drop(s);
  51         assert_eq!(HITS.load(Ordering::SeqCst), n + 4);
  52
  53         let memory = System.allocate(layout.clone()).unwrap();
  54         helper::work_with(&memory);
  55         assert_eq!(HITS.load(Ordering::SeqCst), n + 4);
  56         System.deallocate(memory.as_non_null_ptr(), layout);
  57         assert_eq!(HITS.load(Ordering::SeqCst), n + 4);
  58     }
  59 }