Changeset 278b4a30 in mainline

Timestamp:

2010-05-02T10:41:23Z (14 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

7ed8530

Parents:

0c42638

Message:

Add task_hold() and task_release().

Location:

kernel/generic

Files:

• include/proc/task.h (modified) (1 diff)
• src/proc/task.c (modified) (2 diffs)

kernel/generic/include/proc/task.h

@@ -133 +133 @@
 extern task_t *task_create(as_t *, const char *);
 extern void task_destroy(task_t *);
+extern void task_hold(task_t *);
+extern void task_release(task_t *);
 extern task_t *task_find_by_id(task_id_t);
 extern int task_kill(task_id_t);

kernel/generic/src/proc/task.c

@@ -1 +1 @@
 /*
- * Copyright (c) 2001-2004 Jakub Jermar
+ * Copyright (c) 2010 Jakub Jermar
  * All rights reserved.
  *
@@ -257 +257 @@
 }
 
+/** Hold a reference to a task.
+ *
+ * Holding a reference to a task prevents destruction of that task.
+ *
+ * @param t             Task to be held.
+ */
+void task_hold(task_t *t)
+{
+        atomic_inc(&t->refcount);
+}
+
+/** Release a reference to a task.
+ *
+ * The last one to release a reference to a task destroys the task.
+ *
+ * @param t             Task to be released.
+ */
+void task_release(task_t *t)
+{
+        if ((atomic_predec(&t->refcount)) == 0)
+                task_destroy(t);
+}
+
 /** Syscall for reading task ID from userspace.
  *