X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;fp=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=339a7659e5ae63b00d8547d6ac47656cb81e69a8;hb=2e4e8c2d5207b86e35092e7b6ee3b0d1463138b1;hp=2a61eee064f5af2fa558e73db87f2057fd8eb120;hpb=1c40d25cc62e35f06fec9f6012f8ca042bf9bdbd;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 2a61eee06..339a7659e 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -2301,6 +2301,21 @@ int cmd_data_pending(struct ltt_session *session)
 	if (session->enabled) {
 		ret = LTTNG_ERR_SESSION_STARTED;
 		goto error;
+	} else {
+		/*
+		 * If stopped, just make sure we've started before else the above call
+		 * will always send that there is data pending.
+		 *
+		 * The consumer assumes that when the data pending command is received,
+		 * the trace has been started before or else no output data is written
+		 * by the streams which is a condition for data pending. So, this is
+		 * *VERY* important that we don't ask the consumer before a start
+		 * trace.
+		 */
+		if (!session->started) {
+			ret = 0;
+			goto error;
+		}
 	}
 
 	if (ksess && ksess->consumer) {