Re-import from Subversion.

[pdclib] / functions / stdlib / free.c

diff --git a/functions/stdlib/free.c b/functions/stdlib/free.c
index 5801248ebb22f10631e397976ac76eedca754873..150d7b337ae60167941f87315c6d13be28e0d4bd 100644 (file)
--- a/functions/stdlib/free.c
+++ b/functions/stdlib/free.c
@@ -1,8 +1,48 @@
-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// Public Domain C Library - http://pdclib.sourceforge.net
-// This code is Public Domain. Use, modify, and redistribute at will.
-// ----------------------------------------------------------------------------
+/* ----------------------------------------------------------------------------
+ * $Id$
+ * ----------------------------------------------------------------------------
+ * Public Domain C Library - http://pdclib.sourceforge.net
+ * This code is Public Domain. Use, modify, and redistribute at will.
+ * --------------------------------------------------------------------------*/
 
 void free( void * ptr ) { /* TODO */ };
+
+/* Thomas "Beyond Infinity" Kreitner's code - unchecked, unoptimized
+{
+    chunk_t * chunk;
+    chunk_t * prev_chunk;
+    chunk = used_mem.start;
+    do
+    {
+        prev_chunk = chunk;
+        chunk = chunk->next;
+    } while ( ( chunk != NULL ) && ( chunk->address != ptr ) );
+    if ( chunk->address == ptr )
+    {
+    if( used_mem.start->next->next == NULL )
+    {
+        /* used_mem list has only one entry */
+        chunk = used_mem.start->next;
+        used_mem.last = used_mem.start;
+    }
+    else if ( chunk == used_mem.last )
+    {
+        /* chunk is the last element of used_mem list */
+        prev_chunk->next = NULL;
+        used_mem.last = prev_chunk;
+    }
+    else
+    {
+        /* chunk is neither only nor last in the used_mem list */
+        prev_chunk->next = prev_chunk->next->next;
+    }
+    chunk->next = NULL;
+    free_mem.last->next = chunk;
+    free_mem.last = chunk;
+    return chunk;
+    }
+    else
+    {
+        return NULL;
+    }
+}