From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Tue, 29 Nov 2011 21:39:58 +0000 (-0500)
Subject: ltt_event_create should return error values
X-Git-Tag: v1.9.1~50
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=576599a076803d5306b939bfd8333202919bb56e;p=lttng-ust.git

ltt_event_create should return error values

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/include/lttng/ust-events.h b/include/lttng/ust-events.h
index afcc67f9..0ccef46a 100644
--- a/include/lttng/ust-events.h
+++ b/include/lttng/ust-events.h
@@ -336,9 +336,10 @@ struct ltt_channel *ltt_global_channel_create(struct ltt_session *session,
 				       int *shm_fd, int *wait_fd,
 				       uint64_t *memory_map_size);
 
-struct ltt_event *ltt_event_create(struct ltt_channel *chan,
-				   struct lttng_ust_event *event_param,
-				   void *filter);
+int ltt_event_create(struct ltt_channel *chan,
+		struct lttng_ust_event *event_param,
+		void *filter,
+		struct ltt_event **event);
 
 int ltt_channel_enable(struct ltt_channel *channel);
 int ltt_channel_disable(struct ltt_channel *channel);
diff --git a/liblttng-ust/ltt-events.c b/liblttng-ust/ltt-events.c
index 2595ea89..b852b313 100644
--- a/liblttng-ust/ltt-events.c
+++ b/liblttng-ust/ltt-events.c
@@ -350,25 +350,33 @@ void _ltt_channel_destroy(struct ltt_channel *chan)
 /*
  * Supports event creation while tracing session is active.
  */
-struct ltt_event *ltt_event_create(struct ltt_channel *chan,
-				   struct lttng_ust_event *event_param,
-				   void *filter)
+int ltt_event_create(struct ltt_channel *chan,
+		struct lttng_ust_event *event_param,
+		void *filter,
+		struct ltt_event **_event)
 {
 	struct ltt_event *event;
-	int ret;
+	int ret = 0;
 
-	if (chan->used_event_id == -1UL)
+	if (chan->used_event_id == -1UL) {
+		ret = -ENOMEM;
 		goto full;
+	}
 	/*
 	 * This is O(n^2) (for each event, the loop is called at event
 	 * creation). Might require a hash if we have lots of events.
 	 */
-	cds_list_for_each_entry(event, &chan->session->events, list)
-		if (event->desc && !strcmp(event->desc->name, event_param->name))
+	cds_list_for_each_entry(event, &chan->session->events, list) {
+		if (event->desc && !strcmp(event->desc->name, event_param->name)) {
+			ret = -EEXIST;
 			goto exist;
+		}
+	}
 	event = zmalloc(sizeof(struct ltt_event));
-	if (!event)
+	if (!event) {
+		ret = -ENOMEM;
 		goto cache_error;
+	}
 	event->chan = chan;
 	event->filter = filter;
 	/*
@@ -410,7 +418,8 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 			goto statedump_error;
 	}
 	cds_list_add(&event->list, &chan->session->events);
-	return event;
+	*_event = event;
+	return 0;
 
 statedump_error:
 	if (event->desc) {
@@ -425,7 +434,7 @@ register_error:
 cache_error:
 exist:
 full:
-	return NULL;
+	return ret;
 }
 
 /*
diff --git a/liblttng-ust/lttng-ust-abi.c b/liblttng-ust/lttng-ust-abi.c
index 76af511f..e6ffa41f 100644
--- a/liblttng-ust/lttng-ust-abi.c
+++ b/liblttng-ust/lttng-ust-abi.c
@@ -334,13 +334,14 @@ void lttng_metadata_create_events(int channel_objd)
 		.name = "lttng_ust:metadata",
 	};
 	struct ltt_event *event;
+	int ret;
 
 	/*
 	 * We tolerate no failure path after event creation. It will stay
 	 * invariant for the rest of the session.
 	 */
-	event = ltt_event_create(channel, &metadata_params, NULL);
-	if (!event) {
+	ret = ltt_event_create(channel, &metadata_params, NULL, &event);
+	if (ret < 0) {
 		goto create_error;
 	}
 	return;
@@ -656,9 +657,8 @@ int lttng_abi_create_event(int channel_objd,
 	 * We tolerate no failure path after event creation. It will stay
 	 * invariant for the rest of the session.
 	 */
-	event = ltt_event_create(channel, event_param, NULL);
-	if (!event) {
-		ret = -EINVAL;
+	ret = ltt_event_create(channel, event_param, NULL, &event);
+	if (ret < 0) {
 		goto event_error;
 	}
 	objd_set_private(event_objd, event);