Fix: wrapper random documentation

[lttng-modules.git] / lib / ringbuffer / frontend.h

diff --git a/lib/ringbuffer/frontend.h b/lib/ringbuffer/frontend.h
index 4955b3dd9accf320b76c836838e6ba0406c85ea4..f67edc069385a5a714c913ff1dcefd7b890bd280 100644 (file)
--- a/lib/ringbuffer/frontend.h
+++ b/lib/ringbuffer/frontend.h
@@ -1,33 +1,17 @@
-#ifndef _LIB_RING_BUFFER_FRONTEND_H
-#define _LIB_RING_BUFFER_FRONTEND_H
-
-/*
+/* SPDX-License-Identifier: (GPL-2.0-only OR LGPL-2.1-only)
+ *
  * lib/ringbuffer/frontend.h
  *
  * Ring Buffer Library Synchronization Header (API).
  *
  * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
- * 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; only
- * version 2.1 of the License.
- *
- * 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
- *
- * Author:
- *     Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
  * See ring_buffer_frontend.c for more information on wait-free algorithms.
  */
 
+#ifndef _LIB_RING_BUFFER_FRONTEND_H
+#define _LIB_RING_BUFFER_FRONTEND_H
+
 #include <linux/pipe_fs_i.h>
 #include <linux/rcupdate.h>
 #include <linux/cpumask.h>
@@ -51,6 +35,9 @@
 /* Internal helpers */
 #include <wrapper/ringbuffer/frontend_internal.h>
 
+/* Max ring buffer nesting count, see lib_ring_buffer_get_cpu(). */
+#define RING_BUFFER_MAX_NESTING 4
+
 /* Buffer creation/removal and setup operations */
 
 /*
@@ -106,6 +93,10 @@ extern void lib_ring_buffer_release_read(struct lib_ring_buffer *buf);
 extern int lib_ring_buffer_snapshot(struct lib_ring_buffer *buf,
                                    unsigned long *consumed,
                                    unsigned long *produced);
+extern int lib_ring_buffer_snapshot_sample_positions(
+                                   struct lib_ring_buffer *buf,
+                                   unsigned long *consumed,
+                                   unsigned long *produced);
 extern void lib_ring_buffer_move_consumer(struct lib_ring_buffer *buf,
                                          unsigned long consumed_new);
 
@@ -113,6 +104,9 @@ extern int lib_ring_buffer_get_subbuf(struct lib_ring_buffer *buf,
                                      unsigned long consumed);
 extern void lib_ring_buffer_put_subbuf(struct lib_ring_buffer *buf);
 
+void lib_ring_buffer_set_quiescent_channel(struct channel *chan);
+void lib_ring_buffer_clear_quiescent_channel(struct channel *chan);
+
 /*
  * lib_ring_buffer_get_next_subbuf/lib_ring_buffer_put_next_subbuf are helpers
  * to read sub-buffers sequentially.
@@ -161,7 +155,7 @@ static inline
 int lib_ring_buffer_is_finalized(const struct lib_ring_buffer_config *config,
                                 struct lib_ring_buffer *buf)
 {
-       int finalized = ACCESS_ONCE(buf->finalized);
+       int finalized = READ_ONCE(buf->finalized);
        /*
         * Read finalized before counters.
         */