typedef struct tmout_desc
{
  volatile int active;
  int timestamp;
  void (*func) (void *);
  void *arg;

  struct callout_handle timer;
  struct callout timer;
} tmout_desc_t;

static volatile int next_id = 0;
#define MAX_TMOUTS 128

tmout_desc_t tmouts[MAX_TMOUTS] = { {0} };

int timeout_random = 0x12123400;

static struct mtx oss_timeout_mutex;

void
oss_timer_callback (void *arg)
{
  int ix;
  void (*func) (void *);
  tmout_desc_t *tmout = arg;

  /* oss_timeout_mutex locked by callout */

  timeout_random++;

  if (!tmout->active)
    return;

  arg = tmout->arg;
  tmout->active = 0;
  tmout->timestamp = 0;

  func = tmout->func;
  mtx_unlock(&oss_timeout_mutex);

  tmout->func (arg);
  func (arg);
}

timeout_id_t
oss_timeout (void (*func) (void *), void *arg, unsigned long long ticks)
{
  tmout_desc_t *tmout = NULL;
  int id, n;

  mtx_lock(&oss_timeout_mutex);

  timeout_random++;

  n = 0;
  id = -1;

  while (id == -1 && n < MAX_TMOUTS)

	}

      next_id = (next_id + 1) % MAX_TMOUTS;
    }

  if (id == -1)			/* No timer slots available */
    {
      mtx_unlock(&oss_timeout_mutex);
      cmn_err (CE_CONT, "Timeout table full\n");
      return 0;
    }

  tmout->func = func;
  tmout->arg = arg;
  tmout->timestamp = id | (timeout_random & ~0xff);

  callout_reset(&tmout->timer, ticks, oss_timer_callback, tmout);
  tmout->timer = timeout (oss_timer_callback, tmout, ticks);

  mtx_unlock(&oss_timeout_mutex);

  return id | (timeout_random & ~0xff);
}

void
oss_untimeout (timeout_id_t id)
{
  tmout_desc_t *tmout;
  int ix;

  ix = id & 0xff;
  if (ix < 0 || ix >= MAX_TMOUTS)
    return;

  mtx_lock(&oss_timeout_mutex);

  timeout_random++;
  tmout = &tmouts[ix];

  if (tmout->timestamp != id)	/* Expired timer */
    return;
  if (tmout->active)
    untimeout (oss_timer_callback, tmout, tmout->timer);
    callout_stop(&tmout->timer);
  tmout->active = 0;
  tmout->timestamp = 0;

  mtx_unlock(&oss_timeout_mutex);
}

int
oss_get_procinfo (int what)
{
  switch (what)
    {

  getmicrotime (&timecopy);
  return timecopy.tv_sec;
}

int
soundcard_attach (void)
{
  int i;
  oss_device_t *osdev;

  if (module_lookupbyname("sound") != NULL)
    {
      cmn_err (CE_WARN, "Open Sound System conflicts with FreeBSD driver\n");
      cmn_err (CE_CONT, "Please remove sound(4) from kernel or unload it\n");
      return EBUSY;

#endif

  osdev->major = oss_major;
  oss_register_device (osdev, "OSS core services");

  oss_common_init (osdev);

  mtx_init(&oss_timeout_mutex, "OSS timeout", NULL, MTX_DEF);

  for (i = 0; i < MAX_TMOUTS; ++i)
	callout_init_mtx(&tmouts[i].timer, &oss_timeout_mutex,
			 CALLOUT_RETURNUNLOCKED);

  return 0;
}

int
soundcard_detach (void)
{
  int i;

  if (refcount > 0 || open_devices > 0)
    return EBUSY;

  for (i = 0; i < MAX_TMOUTS; ++i)
	callout_drain(&tmouts[i].timer);

  mtx_destroy(&oss_timeout_mutex);

  oss_unload_drivers ();

  osdev_delete (core_osdev);

  for (i = 0; i < nmemblocks; i++)
    KERNEL_FREE (memblocks[i]);