1 files changed, 26 insertions, 1 deletions
diff --git a/src/lib/wallclock/approx_time.c b/src/lib/wallclock/approx_time.c
index ee498702d5..c815f20e51 100644
--- a/src/lib/wallclock/approx_time.c
+++ b/src/lib/wallclock/approx_time.c
@@ -1,6 +1,6 @@
 /* Copyright (c) 2003, 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 */
 
 /**
@@ -9,7 +9,9 @@
  **/
 
 #include "orconfig.h"
+#include "lib/subsys/subsys.h"
 #include "lib/wallclock/approx_time.h"
+#include "lib/wallclock/wallclock_sys.h"
 
 /* =====
  * Cached time
@@ -41,3 +43,26 @@ update_approx_time(time_t now)
   cached_approx_time = now;
 }
 #endif /* !defined(TIME_IS_FAST) */
+
+/**
+ * Initialize the "wallclock" subsystem by setting the current cached time.
+ **/
+static int
+subsys_wallclock_initialize(void)
+{
+  update_approx_time(time(NULL));
+  return 0;
+}
+
+/**
+ * Subsystem function table describing the "wallclock" subsystem.
+ **/
+const subsys_fns_t sys_wallclock = {
+  .name = "wallclock",
+  SUBSYS_DECLARE_LOCATION(),
+  .supported = true,
+  /* Approximate time is a diagnostic feature, we want it to init right after
+   * low-level error handling. */
+  .level = -98,
+  .initialize = subsys_wallclock_initialize,
+};