diff options
Diffstat (limited to 'src/lib/lock/compat_mutex.c')
| -rw-r--r-- | src/lib/lock/compat_mutex.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/src/lib/lock/compat_mutex.c b/src/lib/lock/compat_mutex.c index 4ad5929715..b0084a3484 100644 --- a/src/lib/lock/compat_mutex.c +++ b/src/lib/lock/compat_mutex.c @@ -1,6 +1,6 @@ /* Copyright (c) 2003-2004, Roger Dingledine * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -29,7 +29,15 @@ tor_mutex_new_nonrecursive(void) tor_mutex_init_nonrecursive(m); return m; } -/** Release all storage and system resources held by <b>m</b>. */ +/** Release all storage and system resources held by <b>m</b>. + * + * Destroying a locked mutex is undefined behaviour. Global mutexes may be + * locked when they are passed to this function, because multiple threads can + * still access them. So we can either: + * - destroy on shutdown, and re-initialise when tor re-initialises, or + * - skip destroying and re-initialisation, using a sentinel variable. + * See #31735 for details. + */ void tor_mutex_free_(tor_mutex_t *m) { |