From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Sat, 5 Nov 2011 15:27:53 +0000 (-0400)
Subject: Fix order of streams
X-Git-Tag: v2.0-pre15~156
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=5af2f756eb72d460d304318550afc782279452b9

Fix order of streams

Use a list instead of hash table to send streams in correct order.

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

diff --git a/include/lttng/lttng-consumer.h b/include/lttng/lttng-consumer.h
index 7751570ef..1a6afc22a 100644
--- a/include/lttng/lttng-consumer.h
+++ b/include/lttng/lttng-consumer.h
@@ -85,6 +85,7 @@ struct lttng_consumer_channel {
 	int nr_streams;
 	int shm_fd_is_copy;
 	int wait_fd_is_copy;
+	int cpucount;
 };
 
 /* Forward declaration for UST. */
diff --git a/liblttng-consumer/lttng-consumer.c b/liblttng-consumer/lttng-consumer.c
index 5311860e0..2fcb39a27 100644
--- a/liblttng-consumer/lttng-consumer.c
+++ b/liblttng-consumer/lttng-consumer.c
@@ -181,6 +181,7 @@ struct lttng_consumer_stream *consumer_allocate_stream(
 	case LTTNG_CONSUMER_KERNEL:
 		break;
 	case LTTNG_CONSUMER_UST:
+		stream->cpu = stream->chan->cpucount++;
 		ret = lttng_ustconsumer_allocate_stream(stream);
 		if (ret) {
 			free(stream);
diff --git a/lttng-sessiond/trace-ust.h b/lttng-sessiond/trace-ust.h
index 35683ebce..604024b18 100644
--- a/lttng-sessiond/trace-ust.h
+++ b/lttng-sessiond/trace-ust.h
@@ -53,7 +53,8 @@ struct ltt_ust_stream {
 	int handle;
 	char pathname[PATH_MAX];
 	struct lttng_ust_object_data *obj;
-	struct cds_lfht_node node;
+	/* Using a list of streams to keep order. */
+	struct cds_list_head list;
 };
 
 /* UST channel */
diff --git a/lttng-sessiond/ust-app.c b/lttng-sessiond/ust-app.c
index bce76f791..9e6b3468b 100644
--- a/lttng-sessiond/ust-app.c
+++ b/lttng-sessiond/ust-app.c
@@ -322,7 +322,7 @@ static struct ust_app_channel *alloc_app_channel(char *name)
 	ua_chan->handle = -1;
 	ua_chan->obj = NULL;
 	ua_chan->ctx = hashtable_new(0);
-	ua_chan->streams = hashtable_new(0);
+	CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
 	ua_chan->events = hashtable_new_str(0);
 	hashtable_node_init(&ua_chan->node, (void *) ua_chan->name,
 			strlen(ua_chan->name));
@@ -788,12 +788,11 @@ int ust_app_start_trace(struct ltt_ust_session *usess)
 				memset(ustream, 0, sizeof(struct ltt_ust_stream));
 				ustream->obj = obj;
 				ustream->handle = ustream->obj->handle;
-				hashtable_node_init(&ustream->node,
-					(void *)((unsigned long) ustream->handle), sizeof(void *));
-				hashtable_add_unique(ua_chan->streams, &ustream->node);
-				ret = snprintf(ustream->pathname, PATH_MAX, "%s/%s_%lu",
+				/* Order is important */
+				cds_list_add_tail(&ustream->list, &ua_chan->streams.head);
+				ret = snprintf(ustream->pathname, PATH_MAX, "%s/%s_%u",
 						uchan->pathname, uchan->name,
-						hashtable_get_count(ua_chan->streams) - 1);
+						ua_chan->streams.count++);
 				if (ret < 0) {
 					PERROR("asprintf UST create stream");
 					goto next_chan;
diff --git a/lttng-sessiond/ust-app.h b/lttng-sessiond/ust-app.h
index 04c3472dd..9a30b6f8f 100644
--- a/lttng-sessiond/ust-app.h
+++ b/lttng-sessiond/ust-app.h
@@ -65,7 +65,7 @@ struct ust_app_channel {
 	char name[LTTNG_UST_SYM_NAME_LEN];
 	struct lttng_ust_channel attr;
 	struct lttng_ust_object_data *obj;
-	struct cds_lfht *streams;
+	struct ltt_ust_stream_list streams;
 	struct cds_lfht *ctx;
 	struct cds_lfht *events;
 	struct cds_lfht_node node;
diff --git a/lttng-sessiond/ust-consumer.c b/lttng-sessiond/ust-consumer.c
index 1e583839e..444ff6eee 100644
--- a/lttng-sessiond/ust-consumer.c
+++ b/lttng-sessiond/ust-consumer.c
@@ -38,8 +38,7 @@ static int send_channel_streams(int sock,
 {
 	int ret, fd;
 	struct lttcomm_consumer_msg lum;
-	struct cds_lfht_iter iter;
-	struct cds_lfht_node *node;
+	struct ltt_ust_stream *stream;
 
 	DBG("Sending streams of channel %s to UST consumer", uchan->name);
 
@@ -66,15 +65,11 @@ static int send_channel_streams(int sock,
 		goto error;
 	}
 
-	rcu_read_lock();
-	hashtable_get_first(uchan->streams, &iter);
-	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
-		struct ltt_ust_stream *stream =
-				caa_container_of(node, struct ltt_ust_stream, node);
+	cds_list_for_each_entry(stream, &uchan->streams.head, list) {
 		int fds[2];
 
 		if (!stream->obj->shm_fd) {
-			goto next;
+			continue;
 		}
 		lum.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
 		lum.u.stream.channel_key = uchan->obj->shm_fd;
@@ -98,11 +93,7 @@ static int send_channel_streams(int sock,
 			perror("send consumer stream ancillary data");
 			goto error;
 		}
-
-next:
-		hashtable_get_next(uchan->streams, &iter);
 	}
-	rcu_read_unlock();
 
 	DBG("consumer channel streams sent");