1 files changed, 88 insertions, 0 deletions
diff --git a/src/core/mainloop/periodic.h b/src/core/mainloop/periodic.h
new file mode 100644
index 0000000000..4c8c3c96cc
--- /dev/null
+++ b/src/core/mainloop/periodic.h
@@ -0,0 +1,88 @@
+/* Copyright (c) 2015-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#ifndef TOR_PERIODIC_H
+#define TOR_PERIODIC_H
+
+#define PERIODIC_EVENT_NO_UPDATE (-1)
+
+/* Tor roles for which a periodic event item is for. An event can be for
+ * multiple roles, they can be combined. */
+#define PERIODIC_EVENT_ROLE_CLIENT      (1U << 0)
+#define PERIODIC_EVENT_ROLE_RELAY       (1U << 1)
+#define PERIODIC_EVENT_ROLE_BRIDGE      (1U << 2)
+#define PERIODIC_EVENT_ROLE_DIRAUTH     (1U << 3)
+#define PERIODIC_EVENT_ROLE_BRIDGEAUTH  (1U << 4)
+#define PERIODIC_EVENT_ROLE_HS_SERVICE  (1U << 5)
+#define PERIODIC_EVENT_ROLE_DIRSERVER   (1U << 6)
+
+/* Helper macro to make it a bit less annoying to defined groups of roles that
+ * are often used. */
+
+/* Router that is a Bridge or Relay. */
+#define PERIODIC_EVENT_ROLE_ROUTER \
+  (PERIODIC_EVENT_ROLE_BRIDGE | PERIODIC_EVENT_ROLE_RELAY)
+/* Authorities that is both bridge and directory. */
+#define PERIODIC_EVENT_ROLE_AUTHORITIES \
+  (PERIODIC_EVENT_ROLE_BRIDGEAUTH | PERIODIC_EVENT_ROLE_DIRAUTH)
+/* All roles. */
+#define PERIODIC_EVENT_ROLE_ALL \
+  (PERIODIC_EVENT_ROLE_AUTHORITIES | PERIODIC_EVENT_ROLE_CLIENT | \
+   PERIODIC_EVENT_ROLE_HS_SERVICE | PERIODIC_EVENT_ROLE_ROUTER)
+
+/*
+ * Event flags which can change the behavior of an event.
+ */
+
+/* Indicate that the event needs the network meaning that if we are in
+ * DisableNetwork or hibernation mode, the event won't be enabled. This obey
+ * the net_is_disabled() check. */
+#define PERIODIC_EVENT_FLAG_NEED_NET  (1U << 0)
+
+/** Callback function for a periodic event to take action.  The return value
+* influences the next time the function will get called.  Return
+* PERIODIC_EVENT_NO_UPDATE to not update <b>last_action_time</b> and be polled
+* again in the next second. If a positive value is returned it will update the
+* interval time. */
+typedef int (*periodic_event_helper_t)(time_t now,
+                                      const or_options_t *options);
+
+struct mainloop_event_t;
+
+/** A single item for the periodic-events-function table. */
+typedef struct periodic_event_item_t {
+  periodic_event_helper_t fn; /**< The function to run the event */
+  time_t last_action_time; /**< The last time the function did something */
+  struct mainloop_event_t *ev; /**< Libevent callback we're using to implement
+                                * this */
+  const char *name; /**< Name of the function -- for debug */
+
+  /* Bitmask of roles define above for which this event applies. */
+  uint32_t roles;
+  /* Bitmask of flags which can change the behavior of the event. */
+  uint32_t flags;
+  /* Indicate that this event has been enabled that is scheduled. */
+  unsigned int enabled : 1;
+} periodic_event_item_t;
+
+/** events will get their interval from first execution */
+#define PERIODIC_EVENT(fn, r, f) { fn##_callback, 0, NULL, #fn, r, f, 0 }
+#define END_OF_PERIODIC_EVENTS { NULL, 0, NULL, NULL, 0, 0, 0 }
+
+/* Return true iff the given event was setup before thus is enabled to be
+ * scheduled. */
+static inline int
+periodic_event_is_enabled(const periodic_event_item_t *item)
+{
+  return item->enabled;
+}
+
+void periodic_event_launch(periodic_event_item_t *event);
+void periodic_event_setup(periodic_event_item_t *event);
+void periodic_event_destroy(periodic_event_item_t *event);
+void periodic_event_reschedule(periodic_event_item_t *event);
+void periodic_event_enable(periodic_event_item_t *event);
+void periodic_event_disable(periodic_event_item_t *event);
+
+#endif /* !defined(TOR_PERIODIC_H) */
+