From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Wed, 16 Jul 2014 14:35:43 +0000 (-0400)
Subject: Fix: document ust_fork_mutex nesting
X-Git-Tag: v2.5.0~3
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=4770bd47f35d74dd6825169bd2548d65df0217ae;p=lttng-ust.git

Fix: document ust_fork_mutex nesting

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index a73808e1..3a3e1d28 100644
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -68,9 +68,14 @@ static int initialized;
  *
  * ust_exit_mutex must never nest in ust_mutex.
  *
+ * ust_fork_mutex must never nest in ust_mutex.
+ *
  * ust_mutex_nest is a per-thread nesting counter, allowing the perf
  * counter lazy initialization called by events within the statedump,
  * which traces while the ust_mutex is held.
+ *
+ * ust_lock nests within the dynamic loader lock (within glibc) because
+ * it is taken within the library constructor.
  */
 static pthread_mutex_t ust_mutex = PTHREAD_MUTEX_INITIALIZER;