commit f205dabf7ae5c8dde9adc3cc39ef7721953abfea Author: Nick Mathewson nickm@torproject.org Date: Mon Dec 11 12:21:00 2017 -0500
Stop using event_base_once().
This function leaks memory when the event_base is freed before the event itself fires. That's not harmful, but it's annoying when trying to debug other memory leaks.
Fixes bug 24584; bugfix on 0.2.8.1-alpha. --- changes/bug24584 | 5 +++++ src/or/main.c | 22 ++++++++++++++++------ 2 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/changes/bug24584 b/changes/bug24584 new file mode 100644 index 000000000..071c7c2a1 --- /dev/null +++ b/changes/bug24584 @@ -0,0 +1,5 @@ + o Minor bugfixes (memory cleanup): + - Avoid possible at-exit memory leaks related to use of Libevent's + event_base_once() function. (This function tends to leak memory + if the event_base is closed before the event fires.) Fixes bug 24584; + bugfix on 0.2.8.1-alpha. diff --git a/src/or/main.c b/src/or/main.c index aae98dd8a..6d58cf341 100644 --- a/src/or/main.c +++ b/src/or/main.c @@ -666,6 +666,9 @@ tell_event_loop_to_run_external_code(void) } }
+/** Event to run 'shutdown did not work callback'. */ +static struct event *shutdown_did_not_work_event = NULL; + /** Failsafe measure that should never actually be necessary: If * tor_shutdown_event_loop_and_exit() somehow doesn't successfully exit the * event loop, then this callback will kill Tor with an assertion failure @@ -699,9 +702,10 @@ tor_shutdown_event_loop_and_exit(int exitcode) * exit normally. */ /* XXXX We should consider this code if it's never used. */ struct timeval ten_seconds = { 10, 0 }; - event_base_once(tor_libevent_get_base(), -1, EV_TIMEOUT, - shutdown_did_not_work_callback, NULL, - &ten_seconds); + shutdown_did_not_work_event = tor_evtimer_new( + tor_libevent_get_base(), + shutdown_did_not_work_callback, NULL); + event_add(shutdown_did_not_work_event, &ten_seconds);
/* Unlike loopexit, loopbreak prevents other callbacks from running. */ tor_event_base_loopbreak(tor_libevent_get_base()); @@ -1341,6 +1345,8 @@ find_periodic_event(const char *name) return NULL; }
+/** Event to run initialize_periodic_events_cb */ +static struct event *initialize_periodic_events_event = NULL; /** Helper, run one second after setup: * Initializes all members of periodic_events and starts them running. * @@ -1352,6 +1358,7 @@ initialize_periodic_events_cb(evutil_socket_t fd, short events, void *data) (void) fd; (void) events; (void) data; + tor_event_free(initialize_periodic_events_event); int i; for (i = 0; periodic_events[i].name; ++i) { periodic_event_launch(&periodic_events[i]); @@ -1380,9 +1387,10 @@ initialize_periodic_events(void) NAMED_CALLBACK(check_dns_honesty);
struct timeval one_second = { 1, 0 }; - event_base_once(tor_libevent_get_base(), -1, EV_TIMEOUT, - initialize_periodic_events_cb, NULL, - &one_second); + initialize_periodic_events_event = tor_evtimer_new( + tor_libevent_get_base(), + initialize_periodic_events_cb, NULL); + event_add(initialize_periodic_events_event, &one_second); }
STATIC void @@ -3384,6 +3392,8 @@ tor_free_all(int postfork) periodic_timer_free(second_timer); teardown_periodic_events(); periodic_timer_free(refill_timer); + tor_event_free(shutdown_did_not_work_event); + tor_event_free(initialize_periodic_events_event);
if (!postfork) { release_lockfile();