commit 62f4d5a2659d2a786c92299fb29a6a6be44f8caf Author: Nick Mathewson nickm@torproject.org Date: Mon Apr 2 16:47:28 2018 -0400
Add a unit test for post-loop events
This test works by having two post-loop events activate one another in a tight loop. If the "post-loop" mechanism didn't work, this would be enough to starve all other events. --- src/test/test_compat_libevent.c | 60 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+)
diff --git a/src/test/test_compat_libevent.c b/src/test/test_compat_libevent.c index 376524c2d..85f69bd62 100644 --- a/src/test/test_compat_libevent.c +++ b/src/test/test_compat_libevent.c @@ -121,10 +121,70 @@ test_compat_libevent_header_version(void *ignored) (void)0; }
+/* Test for postloop events */ + +/* Event callback to increment a counter. */ +static void +increment_int_counter_cb(periodic_timer_t *timer, void *arg) +{ + (void)timer; + int *ctr = arg; + ++*ctr; +} + +static int activated_counter = 0; + +/* Mainloop event callback to activate another mainloop event */ +static void +activate_event_cb(mainloop_event_t *ev, void *arg) +{ + (void)ev; + mainloop_event_t **other_event = arg; + mainloop_event_activate(*other_event); + ++activated_counter; +} + +static void +test_compat_libevent_postloop_events(void *arg) +{ + (void)arg; + mainloop_event_t *a = NULL, *b = NULL; + periodic_timer_t *timed = NULL; + + tor_libevent_postfork(); + + /* If postloop events don't work, then these events will activate one + * another ad infinitum and, and the periodic event will never occur. */ + b = mainloop_event_postloop_new(activate_event_cb, &a); + a = mainloop_event_postloop_new(activate_event_cb, &b); + + int counter = 0; + struct timeval fifty_ms = { 0, 10 * 1000 }; + timed = periodic_timer_new(tor_libevent_get_base(), &fifty_ms, + increment_int_counter_cb, &counter); + + mainloop_event_activate(a); + int r; + do { + r = tor_libevent_run_event_loop(tor_libevent_get_base(), 0); + if (r == -1) + break; + } while (counter < 5); + + tt_int_op(activated_counter, OP_GE, 2); + + done: + mainloop_event_free(a); + mainloop_event_free(b); + periodic_timer_free(timed); +} + struct testcase_t compat_libevent_tests[] = { { "logging_callback", test_compat_libevent_logging_callback, TT_FORK, NULL, NULL }, { "header_version", test_compat_libevent_header_version, 0, NULL, NULL }, + { "postloop_events", test_compat_libevent_postloop_events, + TT_FORK, NULL, NULL }, END_OF_TESTCASES };