X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=urcu%2Fstatic%2Frculfstack.h;fp=urcu%2Fstatic%2Frculfstack.h;h=7caf3c8c0d15f344170c33873f4cb6f4b4d107fa;hb=af7c2dbeac32c663b64ad05e4eca70e18784463b;hp=0000000000000000000000000000000000000000;hpb=acfd099eae9026369f558e73b2a7e35860962d9d;p=urcu.git

diff --git a/urcu/static/rculfstack.h b/urcu/static/rculfstack.h
new file mode 100644
index 0000000..7caf3c8
--- /dev/null
+++ b/urcu/static/rculfstack.h
@@ -0,0 +1,97 @@
+#ifndef _URCU_RCULFSTACK_STATIC_H
+#define _URCU_RCULFSTACK_STATIC_H
+
+/*
+ * rculfstack-static.h
+ *
+ * Userspace RCU library - Lock-Free RCU Stack
+ *
+ * Copyright 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * TO BE INCLUDED ONLY IN LGPL-COMPATIBLE CODE. See rculfstack.h for linking
+ * dynamically with the userspace rcu library.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <urcu/uatomic_arch.h>
+/* A urcu implementation header should be already included. */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void _cds_lfs_node_init_rcu(struct cds_lfs_node_rcu *node)
+{
+}
+
+void _cds_lfs_init_rcu(struct cds_lfs_stack_rcu *s)
+{
+	s->head = NULL;
+}
+
+void _cds_lfs_push_rcu(struct cds_lfs_stack_rcu *s, struct cds_lfs_node_rcu *node)
+{
+	struct cds_lfs_node_rcu *head = NULL;
+
+	for (;;) {
+		struct cds_lfs_node_rcu *old_head = head;
+
+		node->next = head;
+		/*
+		 * uatomic_cmpxchg() implicit memory barrier orders earlier
+		 * stores to node before publication.
+		 */
+		head = uatomic_cmpxchg(&s->head, old_head, node);
+		if (old_head == head)
+			break;
+	}
+}
+
+/*
+ * Should be called under rcu read-side lock.
+ *
+ * The caller must wait for a grace period to pass before freeing the returned
+ * node or modifying the cds_lfs_node_rcu structure.
+ * Returns NULL if stack is empty.
+ */
+struct cds_lfs_node_rcu *
+_cds_lfs_pop_rcu(struct cds_lfs_stack_rcu *s)
+{
+	for (;;) {
+		struct cds_lfs_node_rcu *head;
+
+		head = rcu_dereference(s->head);
+		if (head) {
+			struct cds_lfs_node_rcu *next = rcu_dereference(head->next);
+
+			if (uatomic_cmpxchg(&s->head, head, next) == head) {
+				return head;
+			} else {
+				/* Concurrent modification. Retry. */
+				continue;
+			}
+		} else {
+			/* Empty stack */
+			return NULL;
+		}
+	}
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _URCU_RCULFSTACK_STATIC_H */