aos/events/event_loop.fbs

include "aos/configuration.fbs";

namespace aos.timing;

// Enum indicating why a message failed to send.
enum SendError : byte {
  // Messages were sent faster than allowed on a given channel.
  MESSAGE_SENT_TOO_FAST = 0,
  // The redzone for a message was invalid, implying some form of memory
  // corruption.
  INVALID_REDZONE = 1,
}

// Table used to track how many times a given error occurred.
table SendErrorCount {
  error:SendError (id: 0);
  count:uint (id: 1);
}

// Holds statistics for a time or size sample.
table Statistic {
  average:float = nan (id: 0);
  min:float = nan (id: 1);
  max:float = nan (id: 2);
  standard_deviation:float = nan (id: 3);
}

table Sender {
  // Index into the channel config for this event loop.
  channel_index:int = -1 (id: 0);

  // Number of messages published.
  count:uint (id: 1);
  // Statistics on the size of messages published.
  size:Statistic (id: 2);
  // Counts of how often different errors occurred. There
  // should be an entry for all possible errors, even if no errors occurred
  // since the last timing report. The absence of an entry implies that the
  // error in question was not supported when the log was generated.
  error_counts:[SendErrorCount] (id: 4);

  // Channel for this sender.  Not filled out by default.
  channel:Channel (id: 3);
}

table Watcher {
  // Index into the channel config for this event loop.
  channel_index:int = -1 (id: 0);

  // Number of messages received since the last report.
  count:uint (id: 1);

  // Latency measurement from when the event was generated (send time), and when
  // the handler was started.
  wakeup_latency:Statistic (id: 2);
  // Statistics on the execution time of the handler.
  handler_time:Statistic (id: 3);

  // Channel for this watcher.  Not filled out by default.
  channel:Channel (id: 4);
}

table Fetcher {
  // Index into the channel config for this event loop.
  channel_index:int = -1 (id: 0);

  // Number of messages fetched since the last time this was published.
  count:uint (id: 1);
  // Latency measurement from when the event was generated (send time), and when
  // the message was fetched.
  latency:Statistic (id: 2);

  // Channel for this fetcher.  Not filled out by default.
  channel:Channel (id: 3);
}

table Timer {
  name:string (id: 0);

  // Number of wakeups since the last report.
  count:uint (id: 1);

  // Latency measurement from when the event was generated (send time), and when
  // the handler was started.
  wakeup_latency:Statistic (id: 2);
  // Statistics on the execution time of the handler.
  handler_time:Statistic (id: 3);

  // Maximum number of cycles missed.
}

table Report {
  // Name of the event loop which is publishing this report.
  name:string (id: 0);
  // Identifier for the event loop.  This should change every time a process
  // gets restarted.
  pid:int (id: 1);

  // List of statistics for each watcher, sender, fetcher, timer, and
  // phased loop.
  watchers:[Watcher] (id: 2);
  senders:[Sender] (id: 3);
  fetchers:[Fetcher] (id: 4);
  timers:[Timer] (id: 5);
  phased_loops:[Timer] (id: 6);

  // Total count of Report send failures
  send_failures:uint64 (id: 7);
}

root_type Report;