Changeset 0321109 in mainline

Timestamp:

2010-05-02T13:45:44Z (14 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

6193351

Parents:

9150781

Message:

Add as_hold() and as_release().

Location:

kernel/generic

Files:

• include/mm/as.h (modified) (1 diff)
• src/mm/as.c (modified) (2 diffs)

kernel/generic/include/mm/as.h

@@ -229 +229 @@
 extern as_t *as_create(int);
 extern void as_destroy(as_t *);
+extern void as_hold(as_t *);
+extern void as_release(as_t *);
 extern void as_switch(as_t *, as_t *);
 extern int as_page_fault(uintptr_t, pf_access_t, istate_t *);

kernel/generic/src/mm/as.c

@@ -1 +1 @@
 /*
- * Copyright (c) 2001-2006 Jakub Jermar
+ * Copyright (c) 2010 Jakub Jermar
  * All rights reserved.
  *
@@ -258 +258 @@
 
         slab_free(as_slab, as);
+}
+
+/** Hold a reference to an address space.
+ *
+ * Holding a reference to an address space prevents destruction of that address
+ * space.
+ *
+ * @param a             Address space to be held.
+ */
+void as_hold(as_t *as)
+{
+        atomic_inc(&as->refcount);
+}
+
+/** Release a reference to an address space.
+ *
+ * The last one to release a reference to an address space destroys the address
+ * space.
+ *
+ * @param a             Address space to be released.
+ */
+void as_release(as_t *as)
+{
+        if (atomic_predec(&as->refcount) == 0)
+                as_destroy(as);
 }