library/alloc/tests/heap.rs

   1 use std::alloc::{Allocator, Global, Layout, System};
   2
   3 /// Issue #45955 and #62251.
   4 #[test]
   5 fn alloc_system_overaligned_request() {
   6     check_overalign_requests(System)
   7 }
   8
   9 #[test]
  10 fn std_heap_overaligned_request() {
  11     check_overalign_requests(Global)
  12 }
  13
  14 fn check_overalign_requests<T: Allocator>(allocator: T) {
  15     for &align in &[4, 8, 16, 32] {
  16         // less than and bigger than `MIN_ALIGN`
  17         for &size in &[align / 2, align - 1] {
  18             // size less than alignment
  19             let iterations = 128;
  20             unsafe {
  21                 let pointers: Vec<_> = (0..iterations)
  22                     .map(|_| {
  23                         allocator.allocate(Layout::from_size_align(size, align).unwrap()).unwrap()
  24                     })
  25                     .collect();
  26                 for &ptr in &pointers {
  27                     assert_eq!(
  28                         (ptr.as_non_null_ptr().as_ptr() as usize) % align,
  29                         0,
  30                         "Got a pointer less aligned than requested"
  31                     )
  32                 }
  33
  34                 // Clean up
  35                 for &ptr in &pointers {
  36                     allocator.deallocate(
  37                         ptr.as_non_null_ptr(),
  38                         Layout::from_size_align(size, align).unwrap(),
  39                     )
  40                 }
  41             }
  42         }
  43     }
  44 }