+ /*
+ * Block on interruptible epoll/poll() instead of the message reception
+ * itself as the recvmsg() wrappers always restart on EINTR. We choose
+ * to wait using interruptible epoll/poll() in order to:
+ * 1) Return if a signal occurs,
+ * 2) Not deal with partially received messages.
+ *
+ * The drawback to this approach is that we assume that messages
+ * are complete/well formed. If a message is shorter than its
+ * announced length, receive_message() will block on recvmsg()
+ * and never return (even if a signal is received).
+ */
+ ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC);
+ if (ret < 0) {
+ status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR;
+ goto end_unlock;
+ }
+ ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR);
+ if (ret < 0) {
+ status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR;
+ goto end_clean_poll;
+ }
+ ret = lttng_poll_wait_interruptible(&events, -1);
+ if (ret <= 0) {
+ status = (ret == -1 && errno == EINTR) ?
+ LTTNG_NOTIFICATION_CHANNEL_STATUS_INTERRUPTED :
+ LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR;
+ goto end_clean_poll;
+ }
+