X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lib%2Fringbuffer%2Ffrontend.h;h=41382fe816d8a8643052fd28ddf242b4db9beb9a;hb=a9bda5a02ba444b1dcd80c8326cf5a0d1be535fa;hp=4955b3dd9accf320b76c836838e6ba0406c85ea4;hpb=5671a6610b06175832338ed78db486b59bc5246c;p=lttng-modules.git

diff --git a/lib/ringbuffer/frontend.h b/lib/ringbuffer/frontend.h
index 4955b3dd..41382fe8 100644
--- 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 OR LGPL-2.1)
+ *
  * 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 */
 
 /*
@@ -92,7 +79,7 @@ void *channel_destroy(struct channel *chan);
 #define for_each_channel_cpu(cpu, chan)					\
 	for ((cpu) = -1;						\
 		({ (cpu) = cpumask_next(cpu, (chan)->backend.cpumask);	\
-		   smp_read_barrier_depends(); (cpu) < nr_cpu_ids; });)
+		   smp_rmb(); (cpu) < nr_cpu_ids; });)
 
 extern struct lib_ring_buffer *channel_get_ring_buffer(
 				const struct lib_ring_buffer_config *config,
@@ -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 = LTTNG_READ_ONCE(buf->finalized);
 	/*
 	 * Read finalized before counters.
 	 */