Changeset 678

Timestamp:

Jul 29, 2015, 5:52:17 PM (9 years ago)

Author:

guerin

Message:

malloc: implement aligned malloc/free

Location:

soft/giet_vm/giet_libs

Files:

• malloc.c (modified) (1 diff)
• malloc.h (modified) (1 diff)

soft/giet_vm/giet_libs/malloc.c

@@ -431 +431 @@
 } // end free()
 
-
-
+//////////////////////
+// reference: http://stackoverflow.com/a/6563989/4244300
+void * almalloc( unsigned int align, unsigned int size )
+{
+    unsigned int total_size;
+    void* ptr;
+
+    // check if align is a power of two
+    if ( !align || (align & (align - 1)) )
+        return NULL;
+
+    // reserve memory for data + offset + book-keeping
+    total_size = size + align + sizeof(void*);
+    ptr = malloc( total_size );
+
+    if ( ptr )
+    {
+        void* start = ptr;
+        void** book;
+
+        // find aligned ptr
+        ptr += sizeof(void*);
+        ptr += align - ((unsigned int)ptr % align);
+
+        // keep original ptr just before the actual data
+        book = ptr - sizeof(void*);
+        *book = start;
+    }
+
+    return ptr;
+}
+
+//////////////////////
+void alfree( void* ptr )
+{
+    if ( ptr )
+    {
+        void** book = ptr - sizeof(void*);
+        free(*book);
+    }
+}
 
 // Local Variables:

soft/giet_vm/giet_libs/malloc.h

@@ -101 +101 @@
 extern void free(void * ptr);
 
+extern void* almalloc (unsigned int align, unsigned int size );
+
+extern void alfree(void * ptr);
 
 #endif