Removing heap allocations, Porting to Unix

os_windows.cpp

@@ -1,27 +1,28 @@
+
 //-----------------------------------------------------------------------------
 // Memory
 //-----------------------------------------------------------------------------
-const SizeU os_page_size = 4096;
+const size_t os_page_size = 4096;
 
 function OS_Memory
-os_reserve(SizeU size){
+os_reserve(size_t size){
   OS_Memory result = {};
-  SizeU adjusted_size = align_up(size, os_page_size);
+  size_t adjusted_size = align_up(size, os_page_size);
   result.data = (U8*)VirtualAlloc(0, adjusted_size, MEM_RESERVE, PAGE_READWRITE);
-  assert_msg(result.data, "Failed to reserve virtual memory");
+  assert_message(result.data, "Failed to reserve virtual memory");
   result.reserve = adjusted_size;
   return result;
 }
 
 function B32
-os_commit(OS_Memory *m, SizeU size){
-  SizeU commit = align_up(size, os_page_size);
-  SizeU total_commit = m->commit + commit;
+os_commit(OS_Memory *m, size_t size){
+  size_t commit = align_up(size, os_page_size);
+  size_t total_commit = m->commit + commit;
   total_commit = clamp_top(total_commit, m->reserve);
-  SizeU adjusted_commit = total_commit - m->commit;
+  size_t adjusted_commit = total_commit - m->commit;
   if(adjusted_commit != 0){
     void *result = VirtualAlloc((U8*)m->data + m->commit, adjusted_commit, MEM_COMMIT, PAGE_READWRITE);
-    assert_msg(result, "Failed to commit more memory");
+    assert_message(result, "Failed to commit more memory");
     m->commit += adjusted_commit;
     return true;
   }
@@ -31,7 +32,7 @@ os_commit(OS_Memory *m, SizeU size){
 function void
 os_release(OS_Memory *m){
   BOOL result = VirtualFree(m->data, 0, MEM_RELEASE);
-  assert_msg(result != 0, "Failed to release OS_Memory");
+  assert_message(result != 0, "Failed to release OS_Memory");
   if(result){
     m->data = 0;
     m->commit = 0;
@@ -40,10 +41,10 @@ os_release(OS_Memory *m){
 }
 
 function B32
-os_decommit_pos(OS_Memory *m, SizeU pos){
-  SizeU aligned = align_down(pos, os_page_size);
-  SizeU adjusted_pos = clamp_top(aligned, m->commit);
-  SizeU size_to_decommit = m->commit - adjusted_pos;
+os_decommit_pos(OS_Memory *m, size_t pos){
+  size_t aligned = align_down(pos, os_page_size);
+  size_t adjusted_pos = clamp_top(aligned, m->commit);
+  size_t size_to_decommit = m->commit - adjusted_pos;
   if(size_to_decommit){
     U8 *base_address = m->data + adjusted_pos;
     BOOL result = VirtualFree(base_address, size_to_decommit, MEM_DECOMMIT);
@@ -247,3 +248,56 @@ os_list_dir(Allocator *a, String dir, U32 flags = LIST_NO_FLAGS){
 
   return result;
 }
+
+//-----------------------------------------------------------------------------
+// OS Heap allocator
+//-----------------------------------------------------------------------------
+struct OS_Heap:Allocator{
+  void *handle;
+};
+
+function void *
+os_heap_allocator_proc(Allocator *a, Allocation_Kind kind, void *old_pointer, size_t size){
+  OS_Heap *heap = (OS_Heap *)a;
+  switch(kind){
+    case Allocation_FreeAll:{
+      invalid_codepath;
+      return 0;
+    }
+    case Allocation_Destroy:{
+      BOOL result = HeapDestroy(heap->handle);
+      assert(result != 0);
+      heap->handle = 0;
+      heap->proc = 0;
+      return 0;
+    }
+    case Allocation_Free:{
+      BOOL result = HeapFree(heap->handle, 0, old_pointer);
+      assert(result != 0);
+      return 0;
+    }
+    case Allocation_Alloc:{
+      void *result = HeapAlloc(heap->handle, 0, size);
+      assert(result);
+      return result;
+    }
+    case Allocation_Resize:{
+      void *result = HeapReAlloc(heap->handle, 0, old_pointer, size);
+      assert(result);
+      return result;
+    }
+    default: invalid_codepath;
+  }
+  return 0;
+}
+
+function OS_Heap // max_size == 0 == growing heap
+win32_os_heap_create(B32 multithreaded, size_t initial_size, size_t max_size, String debug_name){
+  OS_Heap result = {};
+  result.debug_name = debug_name;
+  result.proc = os_heap_allocator_proc;
+  result.kind = Allocator_OSHeap;
+  result.handle = HeapCreate(multithreaded ? 0 : HEAP_NO_SERIALIZE, initial_size, max_size);
+  assert(result.handle);
+  return result;
+}