add mutex to linked_list_allocator

1 files changed, 10 insertions, 4 deletions

diff --git a/arch/x86_64/src/memory/heap/linked_list_allocator.cpp b/arch/x86_64/src/memory/heap/linked_list_allocator.cpp
index 22b5757..01838f9 100644
--- a/arch/x86_64/src/memory/heap/linked_list_allocator.cpp
+++ b/arch/x86_64/src/memory/heap/linked_list_allocator.cpp
@@ -13,6 +13,7 @@ namespace teachos::arch::memory::heap
       : heap_start(heap_start)
       , heap_end(heap_end)
       , first(nullptr)
+      , mutex{shared::mutex{}}
   {
     auto const heap_size = heap_end - heap_start;
     exception_handling::assert(
@@ -26,9 +27,10 @@ namespace teachos::arch::memory::heap
   {
     exception_handling::assert(size > min_allocatable_size(),
                                "[Linked List Allocator] Allocated memory cannot be smaller than 16 bytes");
+    mutex.lock();
 
     memory_block * previous = nullptr;
-    auto current = first.load(std::memory_order::relaxed);
+    auto current = first;
 
     while (current != nullptr)
     {
@@ -40,6 +42,8 @@ namespace teachos::arch::memory::heap
       previous = current;
       current = current->next;
     }
+
+    mutex.unlock();
     exception_handling::panic("[Linked List Allocator] Out of memory");
   }
 
@@ -47,12 +51,13 @@ namespace teachos::arch::memory::heap
   {
     exception_handling::assert(size > min_allocatable_size(),
                                "[Linked List Allocator] Allocated memory cannot be smaller than 16 bytes");
+    mutex.lock();
 
     auto const start_address = reinterpret_cast<std::size_t>(pointer);
     auto const end_address = start_address + size;
 
     memory_block * previous = nullptr;
-    auto current = first.load(std::memory_order::relaxed);
+    auto current = first;
 
     while (current != nullptr)
     {
@@ -68,6 +73,7 @@ namespace teachos::arch::memory::heap
     }
 
     coalesce_free_memory_block(previous, current, pointer, size);
+    mutex.unlock();
   }
 
   auto linked_list_allocator::split_free_memory_block(memory_block * previous_block, memory_block * current_block,
@@ -81,11 +87,11 @@ namespace teachos::arch::memory::heap
     // free block (nullptr). Therefore we have to overwrite the first block instead of overwriting its next value.
     if (previous_block == nullptr)
     {
-      first.compare_exchange_weak(previous_block, new_block, std::memory_order::relaxed);
+      first = new_block;
     }
     else
     {
-      previous_block->next.compare_exchange_weak(current_block, new_block, std::memory_order::relaxed);
+      previous_block = new_block;
     }
     clear_memory_block_header(current_block);
     return reinterpret_cast<void *>(start_address);