Timers: Split microsecond timers from BFD code to lib

1 files changed, 207 insertions, 0 deletions

diff --git a/lib/timer.c b/lib/timer.c
new file mode 100644
index 00000000..00ac4b03
--- /dev/null
+++ b/lib/timer.c
@@ -0,0 +1,207 @@
+/*
+ *	BIRD -- Timers
+ *
+ *	(c) 2013--2017 Ondrej Zajicek <santiago@crfreenet.org>
+ *	(c) 2013--2017 CZ.NIC z.s.p.o.
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+
+#include <stdlib.h>
+
+#include "nest/bird.h"
+
+#include "lib/heap.h"
+#include "lib/resource.h"
+#include "lib/timer.h"
+
+
+struct timeloop main_timeloop;
+
+
+#ifdef USE_PTHREADS
+
+#include <pthread.h>
+
+/* Data accessed and modified from proto/bfd/io.c */
+pthread_key_t current_time_key;
+
+static inline struct timeloop *
+timeloop_current(void)
+{
+  return pthread_getspecific(current_time_key);
+}
+
+static inline void
+timeloop_init_current(void)
+{
+  pthread_key_create(&current_time_key, NULL);
+  pthread_setspecific(current_time_key, &main_timeloop);
+}
+
+void wakeup_kick_current(void);
+
+#else
+
+/* Just use main timelooop */
+static inline struct timeloop * timeloop_current(void) { return &main_timeloop; }
+static inline void timeloop_init_current(void) { }
+
+#endif
+
+btime
+current_time(void)
+{
+  return timeloop_current()->last_time;
+}
+
+
+#define TIMER_LESS(a,b)		((a)->expires < (b)->expires)
+#define TIMER_SWAP(heap,a,b,t)	(t = heap[a], heap[a] = heap[b], heap[b] = t, \
+				   heap[a]->index = (a), heap[b]->index = (b))
+
+
+static void
+tm2_free(resource *r)
+{
+  timer2 *t = (timer2 *) r;
+
+  tm2_stop(t);
+}
+
+static void
+tm2_dump(resource *r)
+{
+  timer2 *t = (timer2 *) r;
+
+  debug("(code %p, data %p, ", t->hook, t->data);
+  if (t->randomize)
+    debug("rand %d, ", t->randomize);
+  if (t->recurrent)
+    debug("recur %d, ", t->recurrent);
+  if (t->expires)
+    debug("expires in %d ms)\n", (t->expires - current_time()) TO_MS);
+  else
+    debug("inactive)\n");
+}
+
+
+static struct resclass tm2_class = {
+  "Timer",
+  sizeof(timer2),
+  tm2_free,
+  tm2_dump,
+  NULL,
+  NULL
+};
+
+timer2 *
+tm2_new(pool *p)
+{
+  timer2 *t = ralloc(p, &tm2_class);
+  t->index = -1;
+  return t;
+}
+
+void
+tm2_set(timer2 *t, btime when)
+{
+  struct timeloop *loop = timeloop_current();
+  uint tc = timers_count(loop);
+
+  if (!t->expires)
+  {
+    t->index = ++tc;
+    t->expires = when;
+    BUFFER_PUSH(loop->timers) = t;
+    HEAP_INSERT(loop->timers.data, tc, timer2 *, TIMER_LESS, TIMER_SWAP);
+  }
+  else if (t->expires < when)
+  {
+    t->expires = when;
+    HEAP_INCREASE(loop->timers.data, tc, timer2 *, TIMER_LESS, TIMER_SWAP, t->index);
+  }
+  else if (t->expires > when)
+  {
+    t->expires = when;
+    HEAP_DECREASE(loop->timers.data, tc, timer2 *, TIMER_LESS, TIMER_SWAP, t->index);
+  }
+
+#ifdef CONFIG_BFD
+  /* Hack to notify BFD loops */
+  if ((loop != &main_timeloop) && (t->index == 1))
+    wakeup_kick_current();
+#endif
+}
+
+void
+tm2_start(timer2 *t, btime after)
+{
+  tm2_set(t, current_time() + MAX(after, 0));
+}
+
+void
+tm2_stop(timer2 *t)
+{
+  if (!t->expires)
+    return;
+
+  struct timeloop *loop = timeloop_current();
+  uint tc = timers_count(loop);
+
+  HEAP_DELETE(loop->timers.data, tc, timer2 *, TIMER_LESS, TIMER_SWAP, t->index);
+  BUFFER_POP(loop->timers);
+
+  t->index = -1;
+  t->expires = 0;
+}
+
+void
+timers_init(struct timeloop *loop, pool *p)
+{
+  times_init(loop);
+
+  BUFFER_INIT(loop->timers, p, 4);
+  BUFFER_PUSH(loop->timers) = NULL;
+}
+
+void
+timers_fire(struct timeloop *loop)
+{
+  btime base_time;
+  timer2 *t;
+
+  times_update(loop);
+  base_time = loop->last_time;
+
+  while (t = timers_first(loop))
+  {
+    if (t->expires > base_time)
+      return;
+
+    if (t->recurrent)
+    {
+      btime when = t->expires + t->recurrent;
+
+      if (when <= loop->last_time)
+	when = loop->last_time + t->recurrent;
+
+      if (t->randomize)
+	when += random() % (t->randomize + 1);
+
+      tm2_set(t, when);
+    }
+    else
+      tm2_stop(t);
+
+    t->hook(t);
+  }
+}
+
+void
+timer_init(void)
+{
+  timers_init(&main_timeloop, &root_pool);
+  timeloop_init_current();
+}