Give queued_events_flush_all() responsibility for flushing log cbs

This requires that when a log cb happens, the event for flushing
queued events is scheduled, so we also add the necessary machinery
to have that happen.

Note that this doesn't actually help with logs from outside the main
thread, but those were already suppressed: see #25987 for a ticket
tracking that issue.

diff --git a/src/or/config.c b/src/or/config.c
index 54f3930fc5150fdee80098b455d1ba40b56d1236..208680060f2d75b6788d5a19592018348e60d5a9 100644 (file)
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -1547,6 +1547,7 @@ options_act_reversible(const or_options_t *old_options, char **msg)
       tor_malloc_zero(sizeof(log_severity_list_t));
     close_temp_logs();
     add_callback_log(severity, control_event_logmsg);
+    logs_set_pending_callback_callback(control_event_logmsg_pending);
     control_adjust_event_log_severity();
     tor_free(severity);
     tor_log_update_sigsafe_err_fds();

diff --git a/src/or/control.c b/src/or/control.c
index dda8872182f829a739097fef2355433146956754..7ad9460cc83c1855ef878b458cfa296d150e07e5 100644 (file)
--- a/src/or/control.c
+++ b/src/or/control.c
@@ -803,6 +803,9 @@ queued_event_free_(queued_event_t *ev)
 static void
 queued_events_flush_all(int force)
 {
+  /* Make sure that we get all the pending log events, if there are any. */
+  flush_pending_log_callbacks();
+
   if (PREDICT_UNLIKELY(queued_control_events == NULL)) {
     return;
   }
@@ -6186,7 +6189,7 @@ control_event_logmsg(int severity, uint32_t domain, const char *msg)
   int event;
 
   /* Don't even think of trying to add stuff to a buffer from a cpuworker
-   * thread. */
+   * thread. (See #25987 for plan to fix.) */
   if (! in_main_thread())
     return;
 
@@ -6232,6 +6235,23 @@ control_event_logmsg(int severity, uint32_t domain, const char *msg)
   }
 }
 
+/**
+ * Logging callback: called when there is a queued pending log callback.
+ */
+void
+control_event_logmsg_pending(void)
+{
+  if (! in_main_thread()) {
+    /* We can't handle this case yet, since we're using a
+     * mainloop_event_t to invoke queued_events_flush_all.  We ought to
+     * use a different mechanism instead: see #25987.
+     **/
+    return;
+  }
+  tor_assert(flush_queued_events_event);
+  mainloop_event_activate(flush_queued_events_event);
+}
+
 /** Called whenever we receive new router descriptors: tell any
  * interested control connections.  <b>routers</b> is a list of
  * routerinfo_t's.

diff --git a/src/or/control.h b/src/or/control.h
index 2f312a6638222e2354876c0461baa9eee73b0db9..7f8a0bdb5f6cfd0e0b31b2cefc6b34107b208405 100644 (file)
--- a/src/or/control.h
+++ b/src/or/control.h
@@ -60,6 +60,7 @@ int control_event_conn_bandwidth(connection_t *conn);
 int control_event_conn_bandwidth_used(void);
 int control_event_circuit_cell_stats(void);
 void control_event_logmsg(int severity, uint32_t domain, const char *msg);
+void control_event_logmsg_pending(void);
 int control_event_descriptors_changed(smartlist_t *routers);
 int control_event_address_mapped(const char *from, const char *to,
                                  time_t expires, const char *error,