Ensure that size is a multiple of Hole's alignment to avoid alignment errors

Author: phil-opp

src/hole.rs

@@ -83,7 +83,7 @@ impl HoleList {
 
 /// A block containing free memory. It points to the next hole and thus forms a linked list.
 #[cfg(not(test))]
-struct Hole {
+pub struct Hole {
     size: usize,
     next: Option<Unique<Hole>>,
 }

src/lib.rs

@@ -6,7 +6,8 @@
 #[macro_use]
 extern crate std;
 
-use hole::HoleList;
+use hole::{Hole, HoleList};
+use core::mem;
 
 mod hole;
 #[cfg(test)]
@@ -62,6 +63,7 @@ impl Heap {
         if size < HoleList::min_size() {
             size = HoleList::min_size();
         }
+        let size = align_up(size, mem::align_of::<Hole>());
 
         self.holes.allocate_first_fit(size, align)
     }
@@ -77,6 +79,8 @@ impl Heap {
         if size < HoleList::min_size() {
             size = HoleList::min_size();
         }
+        let size = align_up(size, mem::align_of::<Hole>());
+
         self.holes.deallocate(ptr, size);
     }
 

src/test.rs

@@ -1,7 +1,6 @@
 use std::prelude::v1::*;
 use std::mem::{size_of, align_of};
 use super::*;
-use super::hole::*;
 
 fn new_heap() -> Heap {
     const HEAP_SIZE: usize = 1000;