Initial BFD commit, work in progress.

1 files changed, 587 insertions, 0 deletions

diff --git a/proto/bfd/io.c b/proto/bfd/io.c
new file mode 100644
index 00000000..f7fbc67a
--- /dev/null
+++ b/proto/bfd/io.c
@@ -0,0 +1,587 @@
+
+#include "lib/buffer.h"
+#include "lib/heap.h"
+
+struct birdloop
+{
+  pool *pool;
+
+  int wakeup_fds[2];
+  u8 poll_active;
+
+  xxx_time last_time;
+  xxx_time real_time;
+  u8 use_monotonic_clock;
+
+  BUFFER(timer2 *) timers;
+  list event_list;
+  list sock_list;
+  uint sock_num;
+
+  BUFFER(sock *) poll_sk;
+  BUFFER(struct pollfd) poll_fd;
+  u8 poll_changed;
+  u8 close_scheduled;
+
+};
+
+
+static void times_update_alt(struct birdloop *loop);
+
+static int
+times_init(struct birdloop *loop)
+{
+  struct timespec ts;
+  int rv;
+
+  rv = clock_gettime(CLOCK_MONOTONIC, &ts);
+  if (rv < 0)
+  {
+    // log(L_WARN "Monotonic clock is missing");
+
+    loop->use_monotonic_clock = 0;
+    loop->last_time = 0;
+    loop->real_time = 0;
+    times_update_alt(loop);
+    return;
+  }
+
+  /*
+  if ((tv.tv_sec < 0) || (((s64) tv.tv_sec) > ((s64) 1 << 40)))
+    log(L_WARN "Monotonic clock is crazy");
+  */
+
+  loop->use_monotonic_clock = 1;
+  loop->last_time = (tv.tv_sec S) + (tv.tv_nsec / 1000);
+  loop->real_time = 0;
+}
+
+static void
+times_update_pri(struct birdloop *loop)
+{
+  struct timespec ts;
+  int rv;
+
+  rv = clock_gettime(CLOCK_MONOTONIC, &ts);
+  if (rv < 0)
+    die("clock_gettime: %m");
+
+  xxx_time new_time = (tv.tv_sec S) + (tv.tv_nsec / 1000);
+
+  /*
+  if (new_time < loop->last_time)
+    log(L_ERR "Monotonic clock is broken");
+  */
+
+  loop->last_time = new_time;
+  loop->real_time = 0;
+}
+
+static void
+times_update_alt(struct birdloop *loop)
+{
+  struct timeval tv;
+  int rv;
+
+  rv = gettimeofday(&tv, NULL);
+  if (rv < 0)
+    die("gettimeofday: %m");
+
+  xxx_time new_time = (tv.tv_sec S) + tv.tv_usec;
+  xxx_time delta = new_time - loop->real_time;
+
+  if ((delta < 0) || (delta > (60 S)))
+  {
+    /*
+    if (loop->real_time)
+      log(L_WARN "Time jump, delta %d us", (int) delta);
+    */
+
+    delta = 100 MS;
+  }
+
+  loop->last_time += delta;
+  loop->real_time = new_time;
+}
+
+static void
+times_update(struct birdloop *loop)
+{
+  if (loop->use_monotonic_clock)
+    times_update_pri(loop);
+  else
+    times_update_alt(loop);
+}
+
+
+
+static void
+pipe_new(int *pfds)
+{
+  int pfds[2], rv;
+  sock *sk;
+  
+  rv = pipe(pfds);
+  if (rv < 0)
+    die("pipe: %m");
+
+  if (fcntl(pfds[0], F_SETFL, O_NONBLOCK) < 0)
+    die("fcntl(O_NONBLOCK): %m");
+
+  if (fcntl(pfds[1], F_SETFL, O_NONBLOCK) < 0)
+    die("fcntl(O_NONBLOCK): %m");
+}
+
+static void
+wakeup_init(struct birdloop *loop)
+{
+  pipe_new(loop->wakeup_fds);
+}
+
+static void
+wakeup_drain(struct birdloop *loop)
+{
+  char buf[64];
+  int rv;
+  
+ try:
+  rv = read(loop->wakeup_fds[0], buf, 64);
+  if (rv < 0)
+  {
+    if (errno == EINTR)
+      goto try;
+    if (errno == EAGAIN)
+      return;
+    die("wakeup read: %m");
+  }
+  if (rv == 64)
+    goto try;
+}
+
+static void
+wakeup_kick(struct birdloop *loop)
+{
+  u64 v = 1;
+  int rv;
+
+ try:
+  rv = write(loop->wakeup_fds[1], &v, sizeof(u64));
+  if (rv < 0)
+  {
+    if (errno == EINTR)
+      goto try;
+    if (errno == EAGAIN)
+      return;
+    die("wakeup write: %m");
+  }
+}
+
+
+
+
+static inline uint events_waiting(struct birdloop *loop)
+{ return !EMPTY_LIST(loop->event_list); }
+
+static void
+events_init(struct birdloop *loop)
+{
+  list_init(&poll->event_list);
+}
+
+static void
+events_fire(struct birdloop *loop)
+{
+  times_update(loop);
+  ev_run_list(&loop->event_list);
+}
+
+void
+ev2_schedule(event *e)
+{
+  if (loop->poll_active && EMPTY_LIST(loop->event_list))
+    wakeup_kick(loop);
+
+  if (e->n.next)
+    rem_node(&e->n);
+
+  add_tail(&loop->event_list, &e->n);
+}
+
+
+#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 inline uint timers_count(struct birdloop *loop)
+{ return loop->timers.used - 1; }
+
+static inline timer2 *timers_first(struct birdloop *loop)
+{ return (loop->timers.used > 1) ? loop->timers.data[1] : NULL; }
+
+
+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 sec)\n", t->expires - xxx_now);
+  else
+    debug("inactive)\n");
+}
+
+static struct resclass tm2_class = {
+  "Timer",
+  sizeof(timer),
+  tm2_free,
+  tm2_dump,
+  NULL,
+  NULL
+};
+
+timer2 *
+tm2_new(pool *p)
+{
+  timer2 *t = ralloc(p, &tm2_class);
+  t->index = -1;
+  return t;
+}
+
+void
+tm2_start(timer2 *t, xxx_time after)
+{
+  xxx_time when = loop->last_time + after;
+  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);
+  }
+
+  if (loop->poll_active && (t->index == 1))
+    wakeup_kick(loop);
+}
+
+void
+tm2_stop(timer2 *t)
+{
+  if (!t->expires)
+    return;
+
+  uint tc = timers_count(XXX);
+  HEAP_DELETE(loop->timers.data, tc, timer2 *, TIMER_LESS, TIMER_SWAP, t->index);
+  BUFFER_POP(loop->timers);
+
+  t->index = -1;
+  t->expires = 0;
+}
+
+static void
+timers_init(struct birdloop *loop)
+{
+  BUFFER_INIT(loop->timers, loop->pool, 4);
+  BUFFER_PUSH(loop->timers) = NULL;
+}
+
+static void
+timers_fire(struct birdloop *loop)
+{
+  xxx_time 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)
+    {
+      xxx_time after = t->recurrent;
+      xxx_time delta = loop->last_time - t->expires;
+      
+      if (t->randomize)
+	after += random() % (t->randomize + 1);
+
+      if (delta > after)
+	delta = 0;
+
+      tm2_start(t, after - delta);
+    }
+    else
+      tm2_stop(t);
+
+    t->hook(t);
+  }
+}
+
+
+static void
+sockets_init(struct birdloop *loop)
+{
+  list_init(&poll->sock_list);
+  poll->sock_num = 0;
+
+  BUFFER_INIT(loop->poll_sk, loop->pool, 4);
+  BUFFER_INIT(loop->poll_fd, loop->pool, 4);
+  poll_changed = 0;
+}
+
+static void
+sockets_add(struct birdloop *loop, sock *s)
+{
+  add_tail(&loop->sock_list, &s->n);
+  loop->sock_num++;
+
+  s->index = -1;
+  loop->poll_changed = 1;
+
+  if (loop->poll_active)
+    wakeup_kick(loop);
+}
+
+void
+sk_start(sock *s)
+{
+  sockets_add(xxx_loop, s);
+}
+
+static void
+sockets_remove(struct birdloop *loop, sock *s)
+{
+  rem_node(&s->n);
+  loop->sock_num--;
+
+  if (s->index >= 0)
+    s->poll_sk.data[sk->index] = NULL;
+
+  s->index = -1;
+  loop->poll_changed = 1;
+
+  /* Wakeup moved to sk_stop() */
+}
+
+void
+sk_stop(sock *s)
+{
+  sockets_remove(xxx_loop, s);
+
+  if (loop->poll_active)
+  {
+    loop->close_scheduled = 1;
+    wakeup_kick(loop);
+  }
+  else
+    close(s->fd);
+
+  s->fd = -1;
+}
+
+static inline uint sk_want_events(sock *s)
+{ return (s->rx_hook ? POLLIN : 0) | ((s->ttx != s->tpos) ? POLLOUT : 0); }
+
+static void
+sockets_update(struct birdloop *loop, sock *s)
+{
+  if (s->index >= 0)
+    s->poll_fd.data[s->index].events = sk_want_events(s);
+}
+
+static void
+sockets_prepare(struct birdloop *loop)
+{
+  BUFFER_SET(loop->poll_sk, loop->sock_num + 1);
+  BUFFER_SET(loop->poll_fd, loop->sock_num + 1);
+
+  struct pollfd *pfd = loop->poll_fd.data;
+  sock **psk = loop->poll_sk.data;
+  int i = 0;
+  node *n;
+
+  WALK_LIST(n, &loop->sock_list)
+  {
+    sock *s = SKIP_BACK(sock, n, n);
+
+    ASSERT(i < loop->sock_num);
+
+    s->index = i;
+    *psk = s;
+    pfd->fd = s->fd;
+    pfd->events = sk_want_events(s);
+    pfd->revents = 0;
+
+    pfd++;
+    psk++;
+    i++;
+  }
+
+  ASSERT(i == loop->sock_num);
+
+  /* Add internal wakeup fd */
+  *psk = NULL;
+  pfd->fd = loop->wakeup_fds[0];
+  pfd->events = POLLIN;
+  pfd->revents = 0;
+
+  loop->poll_changed = 0;
+}
+
+static void
+sockets_close_fds(struct birdloop *loop)
+{
+  struct pollfd *pfd = loop->poll_fd.data;
+  sock **psk = loop->poll_sk.data;
+  int poll_num = loop->poll_fd.used - 1;
+
+  int i;
+  for (i = 0; i < poll_num; i++)
+    if (psk[i] == NULL)
+      close(pfd[i].fd);
+
+  loop->close_scheduled = 0;
+}
+
+
+static void
+sockets_fire(struct birdloop *loop)
+{
+  struct pollfd *pfd = loop->poll_fd.data;
+  sock **psk = loop->poll_sk.data;
+  int poll_num = loop->poll_fd.used - 1;
+
+  times_update(loop);
+
+  /* Last fd is internal wakeup fd */
+  if (pfd[loop->sock_num].revents & POLLIN)
+    wakeup_drain(loop);
+
+  int i;
+  for (i = 0; i < poll_num; pfd++, psk++, i++)
+  {
+    int e = 1;
+
+    if (! pfd->revents)
+      continue;
+
+    if (pfd->revents & POLLNVAL)
+      die("poll: invalid fd %d", pfd->fd);
+
+    if (pfd->revents & POLLIN)
+      while (e && *psk && (*psk)->rx_hook)
+	e = sk_read(*psk);
+
+    e = 1;
+    if (pfd->revents & POLLOUT)
+      while (e && *psk)
+	e = sk_write(*psk);
+  }
+}
+
+
+struct birdloop *
+birdloop_new(pool *p)
+{
+  struct birdloop *loop = mb_allocz(p, sizeof(struct birdloop));
+  p->pool = p;
+
+  times_init(loop);
+  wakeup_init(loop);
+
+  events_init(loop);
+  timers_init(loop);
+  sockets_init(loop);
+
+  return loop;
+}
+
+void
+birdloop_enter(struct birdloop *loop)
+{
+  pthread_mutex_lock(loop->mutex);
+}
+
+void
+birdloop_leave(struct birdloop *loop)
+{
+  pthread_mutex_unlock(loop->mutex);
+}
+
+
+void
+birdloop_main(struct birdloop *loop)
+{
+  timer2 *t;
+  int timeout;
+
+  while (1)
+  {
+    events_fire(loop);
+    timers_fire(loop);
+
+    times_update(loop);
+    if (events_waiting(loop))
+      timeout = 0;
+    else if (t = timers_first(loop))
+      timeout = (tm2_remains(t) TO_MS) + 1;
+    else
+      timeout = -1;
+
+    if (loop->poll_changed)
+      sockets_prepare(loop);
+
+    loop->poll_active = 1;
+    pthread_mutex_unlock(loop->mutex);
+
+  try:
+    rv = poll(loop->poll_fd.data, loop->poll_fd.used, timeout);
+    if (rv < 0)
+    {
+      if (errno == EINTR || errno == EAGAIN)
+	goto try;
+      die("poll: %m");
+    }
+
+    pthread_mutex_lock(loop->mutex);
+    loop->poll_active = 0;
+
+    if (loop->close_scheduled)
+      sockets_close_fds(loop);
+
+    if (rv)
+      sockets_fire(loop);
+
+    timers_fire(loop);
+  }
+}
+
+
+