1 files changed, 64 insertions, 0 deletions
diff --git a/lib/settle.h b/lib/settle.h
new file mode 100644
index 00000000..d274599d
--- /dev/null
+++ b/lib/settle.h
@@ -0,0 +1,64 @@
+/*
+ *	BIRD -- Settle timer
+ *
+ *	(c) 2022 Maria Matejka <mq@jmq.cz>
+ *	(c) 2022 CZ.NIC z.s.p.o.
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_SETTLE_H_
+#define _BIRD_SETTLE_H_
+
+#include "lib/birdlib.h"
+#include "lib/timer.h"
+
+struct settle_config {
+  btime min, max;
+};
+
+struct settle {
+  union {
+    /* Timer hook polymorphism. */
+    struct {
+      resource _r;
+      void (*hook)(struct settle *);
+    };
+    timer tm;
+  };
+  struct settle_config cf;
+  btime started;
+};
+
+STATIC_ASSERT(OFFSETOF(struct settle, hook) == OFFSETOF(struct settle, tm) + OFFSETOF(timer, hook));
+
+#define SETTLE_INIT(_cfp, _hook, _data) (struct settle) { .tm = { .data = (_data), }, .hook = (_hook), .cf = ({ASSERT_DIE((_cfp)->min <= (_cfp)->max); *(_cfp); }), }
+
+
+static inline void settle_init(struct settle *s, struct settle_config *cf, void (*hook)(struct settle *), void *data)
+{
+  *s = SETTLE_INIT(cf, hook, data);
+}
+
+#define settle_active(s) tm_active(&(s)->tm)
+
+static inline void settle_kick(struct settle *s, struct birdloop *loop)
+{
+  if (!tm_active(&s->tm))
+  {
+    s->started = current_time();
+    tm_set_in(&s->tm, s->started + s->cf.min, loop);
+  }
+  else
+  {
+    btime now = current_time();
+    tm_set_in(&s->tm, MIN_(now + s->cf.min, s->started + s->cf.max), loop);
+  }
+}
+
+static inline void settle_cancel(struct settle *s)
+{
+  tm_stop(&s->tm);
+}
+
+#endif