From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Wed, 14 Feb 2018 19:59:35 +0000 (-0500)
Subject: Assert that the consumer socket lock is taken during communication
X-Git-Tag: v2.9.8~17
X-Git-Url: http://git.liburcu.org/?p=lttng-tools.git;a=commitdiff_plain;h=11b56a52390b3decde93e8efa5441b16b1842fae

Assert that the consumer socket lock is taken during communication

The consumer_data lock must be acquired during any communication
between the session and consumer daemons.

Stress tests have shown a number of deadlocks that have been
traced down to this type of errors.

Individual fixes follow this commit.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/consumer.c b/src/bin/lttng-sessiond/consumer.c
index 6ee397579..8290b5faf 100644
--- a/src/bin/lttng-sessiond/consumer.c
+++ b/src/bin/lttng-sessiond/consumer.c
@@ -763,6 +763,7 @@ int consumer_send_msg(struct consumer_socket *sock,
 
 	assert(msg);
 	assert(sock);
+	assert(pthread_mutex_trylock(sock->lock) == EBUSY);
 
 	ret = consumer_socket_send(sock, msg, sizeof(struct lttcomm_consumer_msg));
 	if (ret < 0) {