Only flush when there are readers active

[lttng-ust.git] / libringbuffer / frontend_types.h

diff --git a/libringbuffer/frontend_types.h b/libringbuffer/frontend_types.h
index 1d47b275b6fabd3cdc2c5351771662b4989378f7..c23fdd2841e85f808e6505455205c67231be1aac 100644 (file)
--- a/libringbuffer/frontend_types.h
+++ b/libringbuffer/frontend_types.h
@@ -1,22 +1,35 @@
-#ifndef _LINUX_RING_BUFFER_FRONTEND_TYPES_H
-#define _LINUX_RING_BUFFER_FRONTEND_TYPES_H
+#ifndef _LTTNG_RING_BUFFER_FRONTEND_TYPES_H
+#define _LTTNG_RING_BUFFER_FRONTEND_TYPES_H
 
 /*
- * linux/ringbuffer/frontend_types.h
- *
- * (C) Copyright 2005-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * libringbuffer/frontend_types.h
  *
  * Ring Buffer Library Synchronization Header (types).
  *
+ * 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 <string.h>
+#include <time.h>      /* for timer_t */
 
 #include <urcu/list.h>
 #include <urcu/uatomic.h>
@@ -25,6 +38,7 @@
 #include <usterr-signal-safe.h>
 #include "backend_types.h"
 #include "shm_internal.h"
+#include "shm_types.h"
 #include "vatomic.h"
 
 /*
@@ -34,7 +48,7 @@
 enum switch_mode { SWITCH_ACTIVE, SWITCH_FLUSH };
 
 /* channel: collection of per-cpu ring buffers. */
-#define RB_CHANNEL_PADDING     64
+#define RB_CHANNEL_PADDING             32
 struct channel {
        int record_disabled;
        unsigned long commit_count_mask;        /*
@@ -44,17 +58,23 @@ struct channel {
                                                 * subbuffer index.
                                                 */
 
-       unsigned long switch_timer_interval;    /* Buffer flush (jiffies) */
-       unsigned long read_timer_interval;      /* Reader wakeup (jiffies) */
+       unsigned long switch_timer_interval;    /* Buffer flush (us) */
+       timer_t switch_timer;
+       int switch_timer_enabled;
+
+       unsigned long read_timer_interval;      /* Reader wakeup (us) */
+       //timer_t read_timer;
        //wait_queue_head_t read_wait;          /* reader wait queue */
        int finalized;                          /* Has channel been finalized */
        size_t priv_data_offset;
+       unsigned int nr_streams;                /* Number of streams */
+       struct lttng_ust_shm_handle *handle;
+       char padding[RB_CHANNEL_PADDING];
        /*
         * Associated backend contains a variable-length array. Needs to
         * be last member.
         */
        struct channel_backend backend;         /* Associated backend */
-       char padding[RB_CHANNEL_PADDING];
 } __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
 
 /* Per-subbuffer commit counters used on the hot path */
@@ -97,7 +117,6 @@ struct lttng_ust_lib_ring_buffer {
                                         * Active readers count
                                         * standard atomic access (shared)
                                         */
-       long active_shadow_readers;
                                        /* Dropped records */
        union v_atomic records_lost_full;       /* Buffer full */
        union v_atomic records_lost_wrap;       /* Nested wrap-around */
@@ -106,8 +125,6 @@ struct lttng_ust_lib_ring_buffer {
        union v_atomic records_overrun; /* Number of overwritten records */
        //wait_queue_head_t read_wait;  /* reader buffer-level wait queue */
        int finalized;                  /* buffer has been finalized */
-       //struct timer_list switch_timer;       /* timer for periodical switch */
-       //struct timer_list read_timer; /* timer for read poll */
        unsigned long get_subbuf_consumed;      /* Read-side consumed */
        unsigned long prod_snapshot;    /* Producer count snapshot */
        unsigned long cons_snapshot;    /* Consumer count snapshot */
@@ -153,4 +170,4 @@ void *channel_get_private(struct channel *chan)
                _____ret;                                               \
        })
 
-#endif /* _LINUX_RING_BUFFER_FRONTEND_TYPES_H */
+#endif /* _LTTNG_RING_BUFFER_FRONTEND_TYPES_H */