malloc: Update comment for list_lock

(cherry picked from commit 7962541a32eff5597bc4207e781cfac8d1bb0d87)

diff --git a/ChangeLog b/ChangeLog
index d97ce5a354a00051740901c811dbedfe119f8b50..fa02ac9d77cb868cc178f0bb3aba1488993a9e97 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2016-04-13  Florian Weimer  <fweimer@redhat.com>
+
+       * malloc/arena.c (list_lock): Update comment.
+
 2016-04-13  Florian Weimer  <fweimer@redhat.com>
 
        * malloc/tst-malloc-thread-exit.c: Include test-skeleton.c early.

diff --git a/malloc/arena.c b/malloc/arena.c
index 463d31d88fc696ced1d02e4d6444ee1151471be1..f03dcb2aae481713530f53a1c5436edcc4a5982d 100644 (file)
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -85,9 +85,10 @@ static mstate free_list;
    _int_new_arena.  This suffers from data races; see the FIXME
    comments in _int_new_arena and reused_arena.
 
-   list_lock also prevents concurrent forks.  When list_lock is
-   acquired, no arena lock must be acquired, but it is permitted to
-   acquire arena locks after list_lock.  */
+   list_lock also prevents concurrent forks.  At the time list_lock is
+   acquired, no arena lock must have been acquired, but it is
+   permitted to acquire arena locks subsequently, while list_lock is
+   acquired.  */
 static mutex_t list_lock = MUTEX_INITIALIZER;
 
 /* Mapped memory in non-main arenas (reliable only for NO_THREADS). */