Add first pass at a memory validator
diff --git a/test/context.c b/test/context.c
new file mode 100644
index 0000000..04a7a8e
--- /dev/null
+++ b/test/context.c
@@ -0,0 +1,115 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <memory.h>
+#include <assert.h>
+
+#include <cn-cbor\cn-cbor.h>
+
+#include "context.h"
+
+typedef unsigned char byte;
+
+typedef struct {
+ cn_cbor_context context;
+ byte * pFirst;
+} MyContext;
+
+typedef struct _MyItem {
+ struct _MyItem * pNext;
+ size_t size;
+ byte pad[4];
+ byte data[4];
+} MyItem;
+
+
+bool CheckMemory(MyContext * pContext)
+{
+ MyItem * p;
+ int i;
+
+ // Walk memory and check every block
+
+ for (p = (MyItem *) pContext->pFirst; p != NULL; p = p->pNext) {
+ if (p->pad[0] == (byte) 0xab) {
+ // Block has been freed
+ for (i = 0; i < p->size + 8; i++) {
+ if (p->pad[i] != (byte) 0xab) {
+ fprintf(stderr, "Freed block is modified");
+ assert(false);
+ }
+ }
+ }
+ else if (p->pad[0] == (byte) 0xef) {
+ for (i = 0; i < 4; i++) {
+ if ((p->pad[i] != (byte) 0xef) || (p->pad[i + 4 + p->size] != (byte) 0xef)) {
+ fprintf(stderr, "Curent block was overrun");
+ assert(false);
+ }
+ }
+ }
+ else {
+ fprintf(stderr, "Incorrect pad value");
+ assert(false);
+ }
+ }
+
+ return true;
+}
+
+void * MyCalloc(size_t count, size_t size, void * context)
+{
+ MyItem * pb = (MyItem *) malloc(sizeof(MyItem) + count*size);
+ MyContext * myContext = (MyContext *)context;
+
+ CheckMemory(myContext);
+
+ memset(pb, 0xef, sizeof(MyItem) + count*size);
+ memset(&pb->data, 0, count*size);
+
+ pb->pNext = (struct _MyItem *) myContext->pFirst;
+ myContext->pFirst = (byte *) pb;
+ pb->size = count*size;
+
+ return &pb->data;
+}
+
+void MyFree(void * ptr, void * context)
+{
+ MyItem * pb = (MyItem *) ((byte *) ptr - sizeof(MyItem) + 4);
+ MyContext * myContext = (MyContext *)context;
+
+ CheckMemory(myContext);
+
+ memset(&pb->pad, 0xab, pb->size + 8);
+}
+
+
+cn_cbor_context * CreateContext()
+{
+ MyContext * p = malloc(sizeof(MyContext));
+
+ p->context.calloc_func = MyCalloc;
+ p->context.free_func = MyFree;
+ p->context.context = p;
+ p->pFirst = NULL;
+
+ return &p->context;
+}
+
+void FreeContext(cn_cbor_context* pContext)
+{
+ MyContext * myContext = (MyContext *)pContext;
+ MyItem * pItem;
+ MyItem * pItem2;
+
+ CheckMemory(myContext);
+
+ for (pItem = (MyItem *) myContext->pFirst; pItem != NULL; pItem = pItem2) {
+ pItem2 = pItem->pNext;
+ free(pItem);
+ }
+
+ free(myContext);
+
+ return;
+}
