1 files changed, 88 insertions, 0 deletions
diff --git a/source/blender/blenlib/BLI_linklist_lockfree.h b/source/blender/blenlib/BLI_linklist_lockfree.h
new file mode 100644
index 00000000000..7e7400361e3
--- /dev/null
+++ b/source/blender/blenlib/BLI_linklist_lockfree.h
@@ -0,0 +1,88 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2018 Blender Foundation.
+ * All rights reserved.
+ *
+ * Contributor(s): Sergey Sharybin.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+#ifndef __BLI_LINKLIST_LOCKFREE_H__
+#define __BLI_LINKLIST_LOCKFREE_H__
+
+/** \file BLI_linklist_lockfree.h
+ *  \ingroup bli
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct LockfreeLinkNode {
+	struct LockfreeLinkNode *next;
+	/* NOTE: "Subclass" this structure to add custom-defined data. */
+} LockfreeLinkNode;
+
+typedef struct LockfreeLinkList {
+	/* We keep a dummy node at the beginning of the list all the time.
+	 * This allows us to make sure head and tail pointers are always
+	 * valid, and saves from annoying exception cases in insert().
+	 */
+	LockfreeLinkNode dummy_node;
+	/* NOTE: This fields might point to a dummy node. */
+	LockfreeLinkNode *head, *tail;
+} LockfreeLinkList;
+
+typedef void (*LockfreeeLinkNodeFreeFP)(void *link);
+
+/* ************************************************************************** */
+/* NOTE: These functions are NOT safe for use from threads. */
+/* NOTE: !!! I REPEAT: DO NOT USE THEM WITHOUT EXTERNAL LOCK !!! */
+
+/* Make list ready for lock-free access. */
+void BLI_linklist_lockfree_init(LockfreeLinkList *list);
+
+/* Completely free the whole list, it is NOT re-usable after this. */
+void BLI_linklist_lockfree_free(LockfreeLinkList *list,
+                                LockfreeeLinkNodeFreeFP free_func);
+
+/* Remove all the elements from the list, keep it usable for further
+ * inserts.
+ */
+void BLI_linklist_lockfree_clear(LockfreeLinkList *list,
+                                 LockfreeeLinkNodeFreeFP free_func);
+
+
+/* Begin iteration of lock-free linked list, starting with a
+ * first user=defined node. Will ignore the dummy node.
+ */
+LockfreeLinkNode *BLI_linklist_lockfree_begin(LockfreeLinkList *list);
+
+
+/* ************************************************************************** */
+/* NOTE: These functions are safe for use from threads. */
+
+void BLI_linklist_lockfree_insert(LockfreeLinkList *list,
+                                  LockfreeLinkNode *node);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* __BLI_LINKLIST_H__ */