From d636939b51479e7311163ba07dff18c86f2ec6be Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Mon, 20 Jan 2020 14:05:01 +0100
Subject: [PATCH] Add FixedSizeBlockAllocator::fallback_alloc method

---
 src/allocator/fixed_size_block.rs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/allocator/fixed_size_block.rs b/src/allocator/fixed_size_block.rs
index a4c517bb..c83a12cd 100644
--- a/src/allocator/fixed_size_block.rs
+++ b/src/allocator/fixed_size_block.rs
@@ -1,3 +1,6 @@
+use alloc::alloc::Layout;
+use core::ptr;
+
 /// The block sizes to use.
 ///
 /// The sizes must each be power of 2 because they are also used as
@@ -30,4 +33,12 @@ impl FixedSizeBlockAllocator {
     pub unsafe fn init(&mut self, heap_start: usize, heap_size: usize) {
         self.fallback_allocator.init(heap_start, heap_size);
     }
+
+    /// Allocates using the fallback allocator.
+    fn fallback_alloc(&mut self, layout: Layout) -> *mut u8 {
+        match self.fallback_allocator.allocate_first_fit(layout) {
+            Ok(ptr) => ptr.as_ptr(),
+            Err(_) => ptr::null_mut(),
+        }
+    }
 }