Interface TimerScheduler<T>

  • All Known Implementing Classes:
    TimerSchedulerImpl

    public interface TimerScheduler<T>
    Schedules a message to be sent repeatedly to the self actor with a fixed delay between messages.

    It will not compensate the delay between messages if scheduling is delayed longer than specified for some reason. The delay between sending of subsequent messages will always be (at least) the given delay.

    In the long run, the frequency of messages will generally be slightly lower than the reciprocal of the specified delay.

    Each timer has a key and if a new timer with same key is started the previous is cancelled and it's guaranteed that a message from the previous timer is not received, even though it might already be enqueued in the mailbox when the new timer is started.

    • Method Summary

      All Methods Instance Methods Abstract Methods Deprecated Methods 
      Modifier and Type Method Description
      void cancel​(java.lang.Object key)
      Cancel a timer with a given key.
      void cancelAll()
      Cancel all timers.
      boolean isTimerActive​(java.lang.Object key)
      Check if a timer with a given key is active.
      void startPeriodicTimer​(java.lang.Object key, T msg, java.time.Duration interval)
      Deprecated.
      Use startTimerWithFixedDelay or startTimerAtFixedRate instead.
      void startSingleTimer​(java.lang.Object key, T msg, java.time.Duration delay)
      * Start a timer that will send msg once to the self actor after the given delay.
      void startTimerAtFixedRate​(java.lang.Object key, T msg, java.time.Duration interval)
      Schedules a message to be sent repeatedly to the self actor with a given frequency.
      void startTimerWithFixedDelay​(java.lang.Object key, T msg, java.time.Duration delay)
      Schedules a message to be sent repeatedly to the self actor with a fixed delay between messages.
    • Method Detail

      • cancel

        void cancel​(java.lang.Object key)
        Cancel a timer with a given key. If canceling a timer that was already canceled, or key never was used to start a timer this operation will do nothing.

        It is guaranteed that a message from a canceled timer, including its previous incarnation for the same key, will not be received by the actor, even though the message might already be enqueued in the mailbox when cancel is called.

        Parameters:
        key - (undocumented)
      • cancelAll

        void cancelAll()
        Cancel all timers.
      • isTimerActive

        boolean isTimerActive​(java.lang.Object key)
        Check if a timer with a given key is active.
        Parameters:
        key - (undocumented)
        Returns:
        (undocumented)
      • startSingleTimer

        void startSingleTimer​(java.lang.Object key,
                              T msg,
                              java.time.Duration delay)
        * Start a timer that will send msg once to the self actor after the given delay.

        Each timer has a key and if a new timer with same key is started the previous is cancelled and it's guaranteed that a message from the previous timer is not received, even though it might already be enqueued in the mailbox when the new timer is started.

        Parameters:
        key - (undocumented)
        msg - (undocumented)
        delay - (undocumented)
      • startTimerAtFixedRate

        void startTimerAtFixedRate​(java.lang.Object key,
                                   T msg,
                                   java.time.Duration interval)
        Schedules a message to be sent repeatedly to the self actor with a given frequency.

        It will compensate the delay for a subsequent message if the sending of previous message was delayed more than specified. In such cases, the actual message interval will differ from the interval passed to the method.

        If the execution is delayed longer than the interval, the subsequent message will be sent immediately after the prior one. This also has the consequence that after long garbage collection pauses or other reasons when the JVM was suspended all "missed" messages will be sent when the process wakes up again.

        In the long run, the frequency of messages will be exactly the reciprocal of the specified interval.

        Warning: startTimerAtFixedRate can result in bursts of scheduled messages after long garbage collection pauses, which may in worst case cause undesired load on the system. Therefore startTimerWithFixedDelay is often preferred.

        Each timer has a key and if a new timer with same key is started the previous is cancelled and it's guaranteed that a message from the previous timer is not received, even though it might already be enqueued in the mailbox when the new timer is started.

        Parameters:
        key - (undocumented)
        msg - (undocumented)
        interval - (undocumented)
      • startTimerWithFixedDelay

        void startTimerWithFixedDelay​(java.lang.Object key,
                                      T msg,
                                      java.time.Duration delay)
        Schedules a message to be sent repeatedly to the self actor with a fixed delay between messages.

        It will not compensate the delay between messages if scheduling is delayed longer than specified for some reason. The delay between sending of subsequent messages will always be (at least) the given delay.

        In the long run, the frequency of messages will generally be slightly lower than the reciprocal of the specified delay.

        Each timer has a key and if a new timer with same key is started the previous is cancelled and it's guaranteed that a message from the previous timer is not received, even though it might already be enqueued in the mailbox when the new timer is started.

        Parameters:
        key - (undocumented)
        msg - (undocumented)
        delay - (undocumented)