implement heap_realloc

heap.c

@@ -1,4 +1,5 @@
 #include "heap.h"
+#include "cutil.h"
 
 static mblock_t* mblock_get_next(mblock_t* block)
 {
@@ -111,6 +112,19 @@ void* heap_alloc(mheap_t* heap, size_t size)
     return block->data;
 }
 
+void* heap_realloc(mheap_t* heap, void* mem, size_t size)
+{
+    mblock_t* block = (mblock_t*)((u8*)mem - MBLOCK_SIZE);
+    (void)heap;
+    
+    heap_free(heap, mem);
+    void* newMem = heap_alloc(heap, size);
+    if (mem != newMem)
+        cu_memcpy(newMem, mem, mblock_get_size(block));
+    
+    return newMem;
+}
+
 void heap_free(mheap_t* heap, void* mem)
 {
     mblock_t* block = (mblock_t*)((u8*)mem - MBLOCK_SIZE);

heap.h

@@ -29,6 +29,7 @@ void heap_init(mheap_t* heap, void* data, uword size);
 void heap_join(mblock_t* start, int dir);
 void heap_split(mblock_t* block, size_t req_size);
 void* heap_alloc(mheap_t* heap, size_t size);
+void* heap_realloc(mheap_t* heap, void* mem, size_t size);
 void heap_free(mheap_t* heap, void* mem);
 
 #endif

test.c

@@ -200,6 +200,8 @@ int main()
     printf("heap_alloc\t%p\n", m2);
     printf("heap_alloc\t%p\n", m3);
     printf("heap_alloc\t%p\n", m4);
+    void* m5 = heap_realloc(&heap, m4, 10);
+    printf("heap_realloc\t%p\t%p\n", m4, m5);
 
     cutil_exit();
     return 0;