From 976fe9eaae642a5263ec6d7a1572251fa81dbd2f Mon Sep 17 00:00:00 2001
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Mon, 27 Jun 2011 12:04:33 -0400
Subject: [PATCH] Merge LTTng commit e64957da15e3652322dcf6a5389beb01901de8e6

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 libust/ltt-events.c | 46 +++++++++++++++++++++++++++++++++++++++++++--
 libust/ltt-events.h | 11 +++++++++--
 2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/libust/ltt-events.c b/libust/ltt-events.c
index 40e8e459..a94e8f9a 100644
--- a/libust/ltt-events.c
+++ b/libust/ltt-events.c
@@ -82,7 +82,7 @@ void ltt_session_destroy(struct ltt_session *session)
 	kfree(session);
 }
 
-int ltt_session_start(struct ltt_session *session)
+int ltt_session_enable(struct ltt_session *session)
 {
 	int ret = 0;
 	struct ltt_channel *chan;
@@ -119,7 +119,7 @@ end:
 	return ret;
 }
 
-int ltt_session_stop(struct ltt_session *session)
+int ltt_session_disable(struct ltt_session *session)
 {
 	int ret = 0;
 
@@ -135,6 +135,46 @@ end:
 	return ret;
 }
 
+int ltt_channel_enable(struct ltt_channel *channel)
+{
+	int old;
+
+	old = xchg(&channel->enabled, 1);
+	if (old)
+		return -EEXIST;
+	return 0;
+}
+
+int ltt_channel_disable(struct ltt_channel *channel)
+{
+	int old;
+
+	old = xchg(&channel->enabled, 0);
+	if (!old)
+		return -EEXIST;
+	return 0;
+}
+
+int ltt_event_enable(struct ltt_event *event)
+{
+	int old;
+
+	old = xchg(&event->enabled, 1);
+	if (old)
+		return -EEXIST;
+	return 0;
+}
+
+int ltt_event_disable(struct ltt_event *event)
+{
+	int old;
+
+	old = xchg(&event->enabled, 0);
+	if (!old)
+		return -EEXIST;
+	return 0;
+}
+
 static struct ltt_transport *ltt_transport_find(const char *name)
 {
 	struct ltt_transport *transport;
@@ -180,6 +220,7 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 			read_timer_interval);
 	if (!chan->chan)
 		goto create_error;
+	chan->enabled = 1;
 	chan->ops = &transport->ops;
 	list_add(&chan->list, &session->chan);
 	mutex_unlock(&sessions_mutex);
@@ -232,6 +273,7 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 	event->chan = chan;
 	event->filter = filter;
 	event->id = chan->free_event_id++;
+	event->enabled = 1;
 	event->instrumentation = event_param->instrumentation;
 	/* Populate ltt_event structure before tracepoint registration. */
 	smp_wmb();
diff --git a/libust/ltt-events.h b/libust/ltt-events.h
index 05eff540..787868a9 100644
--- a/libust/ltt-events.h
+++ b/libust/ltt-events.h
@@ -164,6 +164,7 @@ struct lttng_probe_desc {
 struct ltt_event {
 	unsigned int id;
 	struct ltt_channel *chan;
+	int enabled;
 	const struct lttng_event_desc *desc;
 	void *filter;
 	struct lttng_ctx *ctx;
@@ -211,6 +212,7 @@ struct ltt_channel_ops {
 struct ltt_channel {
 	unsigned int id;
 	struct channel *chan;		/* Channel buffers */
+	int enabled;
 	struct lttng_ctx *ctx;
 	/* Event ID management */
 	struct ltt_session *session;
@@ -243,8 +245,8 @@ struct ltt_transport {
 };
 
 struct ltt_session *ltt_session_create(void);
-int ltt_session_start(struct ltt_session *session);
-int ltt_session_stop(struct ltt_session *session);
+int ltt_session_enable(struct ltt_session *session);
+int ltt_session_disable(struct ltt_session *session);
 void ltt_session_destroy(struct ltt_session *session);
 
 struct ltt_channel *ltt_channel_create(struct ltt_session *session,
@@ -263,6 +265,11 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 				   struct lttng_kernel_event *event_param,
 				   void *filter);
 
+int ltt_channel_enable(struct ltt_channel *channel);
+int ltt_channel_disable(struct ltt_channel *channel);
+int ltt_event_enable(struct ltt_event *event);
+int ltt_event_disable(struct ltt_event *event);
+
 void ltt_transport_register(struct ltt_transport *transport);
 void ltt_transport_unregister(struct ltt_transport *transport);
 
-- 
2.34.1