X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fcommon%2Fconsumer.c;h=53806b08d8ee4a0dcd54b80ee71edaca221fd784;hb=633d0084183d5b0aed953ce267e0e57e5ef29bd5;hp=a2980e77d29c33b57c4a12889cb82db019956fa0;hpb=d09e1200ec761aef77c721bd648a299eefcc8565;p=lttng-tools.git

diff --git a/src/common/consumer.c b/src/common/consumer.c
index a2980e77d..53806b08d 100644
--- a/src/common/consumer.c
+++ b/src/common/consumer.c
@@ -319,18 +319,20 @@ void consumer_del_stream(struct lttng_consumer_stream *stream)
 	}
 	rcu_read_unlock();
 
-	if (!--stream->chan->refcount) {
+	uatomic_dec(&stream->chan->refcount);
+	if (!uatomic_read(&stream->chan->refcount)
+			&& !uatomic_read(&stream->chan->nb_init_streams)) {
 		free_chan = stream->chan;
 	}
 
-
 	call_rcu(&stream->node.head, consumer_free_stream);
 end:
 	consumer_data.need_update = 1;
 	pthread_mutex_unlock(&consumer_data.lock);
 
-	if (free_chan)
+	if (free_chan) {
 		consumer_del_channel(free_chan);
+	}
 }
 
 struct lttng_consumer_stream *consumer_allocate_stream(
@@ -343,7 +345,8 @@ struct lttng_consumer_stream *consumer_allocate_stream(
 		uid_t uid,
 		gid_t gid,
 		int net_index,
-		int metadata_flag)
+		int metadata_flag,
+		int *alloc_ret)
 {
 	struct lttng_consumer_stream *stream;
 	int ret;
@@ -351,12 +354,13 @@ struct lttng_consumer_stream *consumer_allocate_stream(
 	stream = zmalloc(sizeof(*stream));
 	if (stream == NULL) {
 		perror("malloc struct lttng_consumer_stream");
-		goto end;
+		*alloc_ret = -ENOMEM;
+		return NULL;
 	}
 	stream->chan = consumer_find_channel(channel_key);
 	if (!stream->chan) {
-		perror("Unable to find channel key");
-		goto end;
+		*alloc_ret = -ENOENT;
+		goto error;
 	}
 	stream->chan->refcount++;
 	stream->key = stream_key;
@@ -385,24 +389,37 @@ struct lttng_consumer_stream *consumer_allocate_stream(
 		stream->cpu = stream->chan->cpucount++;
 		ret = lttng_ustconsumer_allocate_stream(stream);
 		if (ret) {
-			free(stream);
-			return NULL;
+			*alloc_ret = -EINVAL;
+			goto error;
 		}
 		break;
 	default:
 		ERR("Unknown consumer_data type");
-		assert(0);
-		goto end;
+		*alloc_ret = -EINVAL;
+		goto error;
 	}
-	DBG("Allocated stream %s (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, out_fd %d, net_seq_idx %d)",
-			stream->path_name, stream->key,
-			stream->shm_fd,
-			stream->wait_fd,
-			(unsigned long long) stream->mmap_len,
-			stream->out_fd,
+
+	/*
+	 * When nb_init_streams reaches 0, we don't need to trigger any action in
+	 * terms of destroying the associated channel, because the action that
+	 * causes the count to become 0 also causes a stream to be added. The
+	 * channel deletion will thus be triggered by the following removal of this
+	 * stream.
+	 */
+	if (uatomic_read(&stream->chan->nb_init_streams) > 0) {
+		uatomic_dec(&stream->chan->nb_init_streams);
+	}
+
+	DBG3("Allocated stream %s (key %d, shm_fd %d, wait_fd %d, mmap_len %llu,"
+			" out_fd %d, net_seq_idx %d)", stream->path_name, stream->key,
+			stream->shm_fd, stream->wait_fd,
+			(unsigned long long) stream->mmap_len, stream->out_fd,
 			stream->net_seq_idx);
-end:
 	return stream;
+
+error:
+	free(stream);
+	return NULL;
 }
 
 /*
@@ -671,7 +688,8 @@ struct lttng_consumer_channel *consumer_allocate_channel(
 		int channel_key,
 		int shm_fd, int wait_fd,
 		uint64_t mmap_len,
-		uint64_t max_sb_size)
+		uint64_t max_sb_size,
+		unsigned int nb_init_streams)
 {
 	struct lttng_consumer_channel *channel;
 	int ret;
@@ -687,6 +705,7 @@ struct lttng_consumer_channel *consumer_allocate_channel(
 	channel->mmap_len = mmap_len;
 	channel->max_sb_size = max_sb_size;
 	channel->refcount = 0;
+	channel->nb_init_streams = nb_init_streams;
 	lttng_ht_node_init_ulong(&channel->node, channel->key);
 
 	switch (consumer_data.type) {
@@ -1520,7 +1539,6 @@ static void destroy_stream_ht(struct lttng_ht *ht)
 static void consumer_del_metadata_stream(struct lttng_consumer_stream *stream)
 {
 	int ret;
-	struct lttng_consumer_channel *free_chan = NULL;
 	struct consumer_relayd_sock_pair *relayd;
 
 	assert(stream);
@@ -1602,12 +1620,10 @@ static void consumer_del_metadata_stream(struct lttng_consumer_stream *stream)
 
 	/* Atomically decrement channel refcount since other threads can use it. */
 	uatomic_dec(&stream->chan->refcount);
-	if (!uatomic_read(&stream->chan->refcount)) {
-		free_chan = stream->chan;
-	}
-
-	if (free_chan) {
-		consumer_del_channel(free_chan);
+	if (!uatomic_read(&stream->chan->refcount)
+			&& !uatomic_read(&stream->chan->nb_init_streams)) {
+		/* Go for channel deletion! */
+		consumer_del_channel(stream->chan);
 	}
 
 	free(stream);
@@ -1707,20 +1723,13 @@ restart:
 					close(ctx->consumer_metadata_pipe[0]);
 					continue;
 				} else if (revents & LPOLLIN) {
-					stream = zmalloc(sizeof(struct lttng_consumer_stream));
-					if (stream == NULL) {
-						PERROR("zmalloc metadata consumer stream");
-						goto error;
-					}
-
 					do {
-						/* Get the stream and add it to the local hash table */
-						ret = read(pollfd, stream,
-								sizeof(struct lttng_consumer_stream));
+						/* Get the stream pointer received */
+						ret = read(pollfd, &stream, sizeof(stream));
 					} while (ret < 0 && errno == EINTR);
-					if (ret < 0 || ret < sizeof(struct lttng_consumer_stream)) {
+					if (ret < 0 ||
+							ret < sizeof(struct lttng_consumer_stream *)) {
 						PERROR("read metadata stream");
-						free(stream);
 						/*
 						 * Let's continue here and hope we can still work
 						 * without stopping the consumer. XXX: Should we?