Fix: ACCESS_ONCE() removed in kernel 4.15

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

diff --git a/lib/ringbuffer/frontend.h b/lib/ringbuffer/frontend.h
index 85858d936ca0c3f43ad1c8b84f5f569b1e5e2e54..1450cb7faf415d7e73f53b07101b534382474b53 100644 (file)
--- a/lib/ringbuffer/frontend.h
+++ b/lib/ringbuffer/frontend.h
@@ -1,19 +1,31 @@
-#ifndef _LINUX_RING_BUFFER_FRONTEND_H
-#define _LINUX_RING_BUFFER_FRONTEND_H
+#ifndef _LIB_RING_BUFFER_FRONTEND_H
+#define _LIB_RING_BUFFER_FRONTEND_H
 
 /*
- * linux/ringbuffer/frontend.h
- *
- * (C) Copyright 2005-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * 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.
- *
- * Dual LGPL v2.1/GPL v2 license.
  */
 
 #include <linux/pipe_fs_i.h>
@@ -37,7 +49,7 @@
 #include <asm/local.h>
 
 /* Internal helpers */
-#include "../../wrapper/ringbuffer/frontend_internal.h"
+#include <wrapper/ringbuffer/frontend_internal.h>
 
 /* Buffer creation/removal and setup operations */
 
@@ -94,6 +106,10 @@ 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);
 
@@ -101,6 +117,9 @@ 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.
@@ -149,7 +168,7 @@ 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.
         */
@@ -163,6 +182,12 @@ int lib_ring_buffer_channel_is_finalized(const struct channel *chan)
        return chan->finalized;
 }
 
+static inline
+int lib_ring_buffer_channel_is_disabled(const struct channel *chan)
+{
+       return atomic_read(&chan->record_disabled);
+}
+
 static inline
 unsigned long lib_ring_buffer_get_read_data_size(
                                const struct lib_ring_buffer_config *config,
@@ -219,4 +244,4 @@ unsigned long lib_ring_buffer_get_records_read(
        return v_read(config, &buf->backend.records_read);
 }
 
-#endif /* _LINUX_RING_BUFFER_FRONTEND_H */
+#endif /* _LIB_RING_BUFFER_FRONTEND_H */