Function note_record_taskname

drivers/note/note_driver.c:501–562

 ****************************************************************************/

static void note_record_taskname(pid_t pid, FAR const char *name)
{
  FAR struct note_taskname_info_s *ti;
  size_t tilen;
  size_t namelen;
  size_t skiplen;
  size_t remain;

  namelen = strlen(name);
  DEBUGASSERT(namelen <= CONFIG_TASK_NAME_SIZE);
  tilen = sizeof(struct note_taskname_info_s) + namelen;
  DEBUGASSERT(tilen <= UCHAR_MAX);

  skiplen = CONFIG_DRIVERS_NOTE_TASKNAME_BUFSIZE - g_note_taskname.head;
  if (skiplen >= tilen + sizeof(struct note_taskname_info_s))
    {
      skiplen = 0; /* Have enough space at the tail - needn't skip */
    }

  if (g_note_taskname.head >= g_note_taskname.tail)
    {
      remain = CONFIG_DRIVERS_NOTE_TASKNAME_BUFSIZE -
               (g_note_taskname.head - g_note_taskname.tail);
    }
  else
    {
      remain = g_note_taskname.tail - g_note_taskname.head;
    }

  while (skiplen + tilen >= remain)
    {
      /* No enough space, drop the old info */

      ti = (FAR struct note_taskname_info_s *)
            &g_note_taskname.buffer[g_note_taskname.tail];
      g_note_taskname.tail = (g_note_taskname.tail + ti->size) %
                             CONFIG_DRIVERS_NOTE_TASKNAME_BUFSIZE;
      remain += ti->size;
    }

  if (skiplen)
    {
      /* Fill the skipped region with an invalid info */

      ti = (FAR struct note_taskname_info_s *)
            &g_note_taskname.buffer[g_note_taskname.head];
      ti->size = skiplen;
      ti->pid = INVALID_PROCESS_ID;
      ti->name[0] = '\0';

      /* Move to the begin of circle buffer */

      g_note_taskname.head = 0;
    }

  ti = (FAR struct note_taskname_info_s *)
        &g_note_taskname.buffer[g_note_taskname.head];
  ti->size = NOTE_ALIGN(tilen);