Fix deadlock: don't take channel lock in timer

[lttng-tools.git] / src / common / consumer.c

diff --git a/src/common/consumer.c b/src/common/consumer.c
index a26a41554d2e379c2e97ad4cca20929627571468..6cf85d96a75b0afa69994886d9a94d91a7faaa29 100644 (file)
--- a/src/common/consumer.c
+++ b/src/common/consumer.c
@@ -551,6 +551,7 @@ static int add_stream(struct lttng_consumer_stream *stream,
 
        pthread_mutex_lock(&consumer_data.lock);
        pthread_mutex_lock(&stream->chan->lock);
+       pthread_mutex_lock(&stream->chan->timer_lock);
        pthread_mutex_lock(&stream->lock);
        rcu_read_lock();
 
@@ -588,6 +589,7 @@ static int add_stream(struct lttng_consumer_stream *stream,
 
        rcu_read_unlock();
        pthread_mutex_unlock(&stream->lock);
+       pthread_mutex_unlock(&stream->chan->timer_lock);
        pthread_mutex_unlock(&stream->chan->lock);
        pthread_mutex_unlock(&consumer_data.lock);
 
@@ -838,6 +840,7 @@ struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
        channel->tracefile_count = tracefile_count;
        channel->monitor = monitor;
        pthread_mutex_init(&channel->lock, NULL);
+       pthread_mutex_init(&channel->timer_lock, NULL);
 
        /*
         * In monitor mode, the streams associated with the channel will be put in
@@ -884,6 +887,7 @@ int consumer_add_channel(struct lttng_consumer_channel *channel,
 
        pthread_mutex_lock(&consumer_data.lock);
        pthread_mutex_lock(&channel->lock);
+       pthread_mutex_lock(&channel->timer_lock);
        rcu_read_lock();
 
        lttng_ht_lookup(consumer_data.channel_ht, &channel->key, &iter);
@@ -900,6 +904,7 @@ int consumer_add_channel(struct lttng_consumer_channel *channel,
 
 end:
        rcu_read_unlock();
+       pthread_mutex_unlock(&channel->timer_lock);
        pthread_mutex_unlock(&channel->lock);
        pthread_mutex_unlock(&consumer_data.lock);
 
@@ -1153,6 +1158,7 @@ struct lttng_consumer_local_data *lttng_consumer_create(
 
        ctx->consumer_error_socket = -1;
        ctx->consumer_metadata_socket = -1;
+       pthread_mutex_init(&ctx->metadata_socket_lock, NULL);
        /* assign the callbacks */
        ctx->on_buffer_ready = buffer_ready;
        ctx->on_recv_channel = recv_channel;
@@ -1955,8 +1961,8 @@ void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
 end:
        /*
         * Nullify the stream reference so it is not used after deletion. The
-        * consumer data lock MUST be acquired before being able to check for a
-        * NULL pointer value.
+        * channel lock MUST be acquired before being able to check for
+        * a NULL pointer value.
         */
        stream->chan->metadata_stream = NULL;
 
@@ -1990,6 +1996,7 @@ static int add_metadata_stream(struct lttng_consumer_stream *stream,
 
        pthread_mutex_lock(&consumer_data.lock);
        pthread_mutex_lock(&stream->chan->lock);
+       pthread_mutex_lock(&stream->chan->timer_lock);
        pthread_mutex_lock(&stream->lock);
 
        /*
@@ -2036,6 +2043,7 @@ static int add_metadata_stream(struct lttng_consumer_stream *stream,
 
        pthread_mutex_unlock(&stream->lock);
        pthread_mutex_unlock(&stream->chan->lock);
+       pthread_mutex_unlock(&stream->chan->timer_lock);
        pthread_mutex_unlock(&consumer_data.lock);
        return ret;
 }