X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fkernel-consumer%2Fkernel-consumer.c;h=46413eda6e710d9e2f934df9e49336a5fd6fcef0;hp=c762934ff92a55569b9323852589157e3e4ceb81;hb=ca22feea083301934d1c8511851c86fb008c0697;hpb=50f8ae690312d8f824fb9c9875b0a07f4a2547b6

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index c762934ff..46413eda6 100644
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -168,6 +168,7 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 				msg.u.stream.gid,
 				msg.u.stream.net_index,
 				msg.u.stream.metadata_flag,
+				msg.u.stream.session_id,
 				&alloc_ret);
 		if (new_stream == NULL) {
 			switch (alloc_ret) {
@@ -279,6 +280,11 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 
 		goto end_nosignal;
 	}
+	case LTTNG_CONSUMER_DATA_AVAILABLE:
+	{
+		rcu_read_unlock();
+		return -ENOSYS;
+	}
 	default:
 		goto end_nosignal;
 	}
@@ -466,3 +472,42 @@ error:
 	return ret;
 }
 
+/*
+ * Check if data is still being extracted from the buffers for a specific
+ * stream. Consumer data lock MUST be acquired before calling this function.
+ *
+ * Return 0 if the traced data are still getting read else 1 meaning that the
+ * data is available for trace viewer reading.
+ */
+int lttng_kconsumer_data_available(struct lttng_consumer_stream *stream)
+{
+	int ret;
+
+	assert(stream);
+
+	/*
+	 * Try to lock the stream mutex. On failure, we know that the stream is
+	 * being used else where hence there is data still being extracted.
+	 */
+	ret = pthread_mutex_trylock(&stream->lock);
+	if (ret == EBUSY) {
+		goto data_not_available;
+	}
+	/* The stream is now locked so we can do our ustctl calls */
+
+	ret = kernctl_get_next_subbuf(stream->wait_fd);
+	if (ret == 0) {
+		/* There is still data so let's put back this subbuffer. */
+		ret = kernctl_put_subbuf(stream->wait_fd);
+		assert(ret == 0);
+		pthread_mutex_unlock(&stream->lock);
+		goto data_not_available;
+	}
+
+	/* Data is available to be read for this stream. */
+	pthread_mutex_unlock(&stream->lock);
+	return 1;
+
+data_not_available:
+	return 0;
+}