From c81265e6459403444c859758db53a9675c3a4ec7 Mon Sep 17 00:00:00 2001
From: batt <batt@38d2e660-2303-0410-9eaa-f027e97ec537>
Date: Wed, 23 Dec 2009 16:49:42 +0000
Subject: [PATCH] Check for alignment of heap memory buffer; add utility macro
 used to declare a heap.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@3127 38d2e660-2303-0410-9eaa-f027e97ec537
---
 bertos/struct/heap.c | 28 +++++++++++++---------------
 bertos/struct/heap.h | 24 +++++++++++++++++++++---
 2 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/bertos/struct/heap.c b/bertos/struct/heap.c
index dc8ceaab..27f80325 100644
--- a/bertos/struct/heap.c
+++ b/bertos/struct/heap.c
@@ -38,28 +38,26 @@
 
 #include "heap.h"
 
-#include <cfg/macros.h>           // IS_POW2()
-#include <cfg/debug.h>            // ASSERT()
-
-#include <string.h>           // memset()
-
-/* NOTE: struct size must be a 2's power! */
-typedef struct _MemChunk
-{
-	struct _MemChunk *next;
-	size_t size;
-} MemChunk;
-
-STATIC_ASSERT(IS_POW2(sizeof(MemChunk)));
+#include <cfg/debug.h> // ASSERT()
+#include <string.h>    // memset()
 
 #define FREE_FILL_CODE     0xDEAD
 #define ALLOC_FILL_CODE    0xBEEF
 
+
+/*
+ * This function prototype is deprecated, will change in:
+ * void heap_init(struct Heap* h, heap_buf_t* memory, size_t size)
+ * in the nex BeRTOS release.
+ */
 void heap_init(struct Heap* h, void* memory, size_t size)
 {
-#ifdef _DEBUG
+	#ifdef _DEBUG
 	memset(memory, FREE_FILL_CODE, size);
-#endif
+	#endif
+
+	ASSERT2((((uintptr_t)memory % sizeof(heap_buf_t)) == 0),
+	"memory buffer is unaligned, please use the HEAP_DEFINE_BUF() macro to declare heap buffers!\n");
 
 	/* Initialize heap with a single big chunk */
 	h->FreeList = (MemChunk *)memory;
diff --git a/bertos/struct/heap.h b/bertos/struct/heap.h
index 7044f331..7bddcba2 100644
--- a/bertos/struct/heap.h
+++ b/bertos/struct/heap.h
@@ -45,15 +45,33 @@
 
 #include "cfg/cfg_heap.h"
 #include <cfg/compiler.h>
+#include <cfg/macros.h> // IS_POW2()
 
-struct _MemChunk;
+/* NOTE: struct size must be a 2's power! */
+typedef struct _MemChunk
+{
+	struct _MemChunk *next;
+	size_t size;
+} MemChunk;
+
+STATIC_ASSERT(IS_POW2(sizeof(MemChunk)));
+
+typedef MemChunk heap_buf_t;
 
 /// A heap
-struct Heap
+typedef struct Heap
 {
 	struct _MemChunk *FreeList;     ///< Head of the free list
-};
+} Heap;
 
+/**
+ * Utility macro to allocate a heap of size \a size.
+ *
+ * \param name Variable name for the heap.
+ * \param size Heap size in bytes.
+ */
+#define HEAP_DEFINE_BUF(name, size) \
+	heap_buf_t name[((size) + sizeof(heap_buf_t) - 1) / sizeof(heap_buf_t)];
 
 /// Initialize \a heap within the buffer pointed by \a memory which is of \a size bytes
 void heap_init(struct Heap* heap, void* memory, size_t size);
-- 
2.25.1