Always initialize the periodic events list.

Various places in our code try to activate these events or check
their status, so we should make sure they're initialized as early as
possible.  Fixes bug 27861; bugfix on 0.3.5.1-alpha.

3 files changed, 16 insertions, 7 deletions

diff --git a/changes/bug27861 b/changes/bug27861
new file mode 100644
index 0000000000..377d68e320
--- /dev/null
+++ b/changes/bug27861
@@ -0,0 +1,4 @@
+  o Major bugfixes (initialization, crash):
+    - Fix an assertion crash that would stop Tor from starting up if
+      the code tried to activate a periodic event too early. Fixes bug
+      27861; bugfix on 0.3.5.1-alpha.
diff --git a/src/core/mainloop/mainloop.c b/src/core/mainloop/mainloop.c
index 4a9da43c9c..6e7033ec4b 100644
--- a/src/core/mainloop/mainloop.c
+++ b/src/core/mainloop/mainloop.c
@@ -1535,7 +1535,9 @@ initialize_periodic_events_cb(evutil_socket_t fd, short events, void *data)
 STATIC void
 initialize_periodic_events(void)
 {
-  tor_assert(periodic_events_initialized == 0);
+  if (periodic_events_initialized)
+    return;
+
   periodic_events_initialized = 1;
 
   /* Set up all periodic events. We'll launch them by roles. */
@@ -2682,6 +2684,8 @@ dns_servers_relaunch_checks(void)
 void
 initialize_mainloop_events(void)
 {
+  initialize_periodic_events();
+
   if (!schedule_active_linked_connections_event) {
     schedule_active_linked_connections_event =
       mainloop_event_postloop_new(schedule_active_linked_connections_cb, NULL);
@@ -2699,10 +2703,7 @@ do_main_loop(void)
   /* initialize the periodic events first, so that code that depends on the
    * events being present does not assert.
    */
-  if (! periodic_events_initialized) {
-    initialize_periodic_events();
-  }
-
+  initialize_periodic_events();
   initialize_mainloop_events();
 
   /* set up once-a-second callback. */
diff --git a/src/test/test_periodic_event.c b/src/test/test_periodic_event.c
index 7804a9d8fb..86dedd85d8 100644
--- a/src/test/test_periodic_event.c
+++ b/src/test/test_periodic_event.c
@@ -87,15 +87,19 @@ test_pe_launch(void *arg)
     item->fn = dumb_event_fn;
   }
 
-  /* Lets make sure that before intialization, we can't scan the periodic
-   * events list and launch them. Lets try by being a Client. */
   options = get_options_mutable();
   options->SocksPort_set = 1;
   periodic_events_on_new_options(options);
+#if 0
+  /* Lets make sure that before intialization, we can't scan the periodic
+   * events list and launch them. Lets try by being a Client. */
+  /* XXXX We make sure these events are initialized now way earlier than we
+   * did before. */
   for (int i = 0; periodic_events[i].name; ++i) {
     periodic_event_item_t *item = &periodic_events[i];
     tt_int_op(periodic_event_is_enabled(item), OP_EQ, 0);
   }
+#endif
 
   initialize_periodic_events();