Relayd data available command support

[lttng-tools.git] / src / bin / lttng-sessiond / consumer.c

diff --git a/src/bin/lttng-sessiond/consumer.c b/src/bin/lttng-sessiond/consumer.c
index 071135bda6975b09abf4f4db7841454dfecdc269..061ec1219c90ad5ef3bd0ea4e217424927864358 100644 (file)
--- a/src/bin/lttng-sessiond/consumer.c
+++ b/src/bin/lttng-sessiond/consumer.c
@@ -695,3 +695,67 @@ int consumer_set_subdir(struct consumer_output *consumer,
 error:
        return ret;
 }
+
+/*
+ * Ask the consumer if the data is ready to bread (available) for the specific
+ * session id.
+ *
+ * This function has a different behavior with the consumer i.e. that it waits
+ * for a reply from the consumer if yes or no the data is available.
+ */
+int consumer_is_data_available(unsigned int id,
+               struct consumer_output *consumer)
+{
+       int ret;
+       int32_t ret_code;
+       struct consumer_socket *socket;
+       struct lttng_ht_iter iter;
+       struct lttcomm_consumer_msg msg;
+
+       assert(consumer);
+
+       msg.cmd_type = LTTNG_CONSUMER_DATA_AVAILABLE;
+
+       msg.u.data_available.session_id = (uint64_t) id;
+
+       DBG3("Consumer data available for id %u", id);
+
+       /* Send command for each consumer */
+       cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter, socket,
+                       node.node) {
+               /* Code flow error */
+               assert(socket->fd >= 0);
+
+               pthread_mutex_lock(socket->lock);
+
+               ret = lttcomm_send_unix_sock(socket->fd, &msg, sizeof(msg));
+               if (ret < 0) {
+                       PERROR("send consumer data available command");
+                       pthread_mutex_unlock(socket->lock);
+                       goto error;
+               }
+
+               /*
+                * Waiting for the reply code where 0 the data is not available and 1
+                * it is for trace reading.
+                */
+               ret = lttcomm_recv_unix_sock(socket->fd, &ret_code, sizeof(ret_code));
+               if (ret < 0) {
+                       PERROR("recv consumer data available status");
+                       pthread_mutex_unlock(socket->lock);
+                       goto error;
+               }
+
+               pthread_mutex_unlock(socket->lock);
+
+               if (ret_code == 0) {
+                       break;
+               }
+       }
+
+       DBG("Consumer data available ret %d", ret_code);
+       return ret_code;
+
+error:
+       return -1;
+}