ark::pipeline::PeriodicTimer

Defined in header “ark/pipeline/periodic_timer.hh”.

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A timer that is used to execute a function periodically. That function takes in the current time. This allows you to deterministically execute functions at some fixed rate.

Methods

• PeriodicTimer(PeriodicTimerConfiguration config)
  Constructor. Initialize a timer with the given configuration.

• ~PeriodicTimer()
  Virtual destructor, for cleanup.

• void reset_to_time(const std::chrono::steady_clock::time_point & time)
  Resets the timer to the given timestamp. No executions will occur, and future ticks/elapsed calls will be relative to this timestamp. All elapsed time will be erased.

• bool tick(const std::chrono::steady_clock::time_point & now)
  Called periodically with the current clock (virtual or otherwise). This will register the times that a timer should execute, so that downstream code can take care of executing them.

  Returns true if execute() will need to be invoked, false otherwise.

• size_t queue_size()
  Returns the number of executions remaining (the number of times you can invoke execute()).

• bool pop(TimerWorkItem & item)
  Pops the oldest execution off the queue and returns a work item. This is the first phase of execution, allowing you to deterministically pop an execution time off the timer, and execute it in a background thread.

  Returns true if the pop was successful, false if the queue is empty.

• void execute_work_item(TimerWorkItem && item)
  The second half of timer execution. Consumes the given timer work item as received from pop(), taking ownership of it, and then invokes the callback.

• bool execute()
  Pops the oldest execution off the queue and executes the callback against it. Returns true if something was executed, or false otherwise.

• std::chrono::nanoseconds time_remaining(const std::chrono::steady_clock::time_point & now)
  Returns the amount of time left before the next execution, based on the given timestamp.

• TimerStatistics statistics()
  Returns statistics related to this timer.

• TimerCallbackTimings timings()
  Returns timing information related to this timer’s callback.

• std::chrono::nanoseconds configured_expected_runtime()
  Returns the configured execution time for this timer.

• std::chrono::nanoseconds expected_runtime(const TimerWorkItem & item)
  Returns the expected runtime as if this timer had executed the given work item.

• std::string name()
  Returns the human-readable name assigned to the timer.