Class Notifier

java.lang.Object
org.wpilib.system.Notifier
All Implemented Interfaces:
AutoCloseable
public class Notifier extends Object implements AutoCloseable
Notifiers run a user-provided callback function on a separate thread.

If startSingle() is used, the callback will run once. If startPeriodic() is used, the callback will run repeatedly with the given period until stop() is called.

  • Constructor Details

    • Notifier

      public Notifier(Runnable callback)
      Create a Notifier with the given callback.

      Configure when the callback runs with startSingle() or startPeriodic().

      Parameters:
      callback - The callback to run.

  • Method Details

    • close

      public void close()
      Specified by:
      close in interface AutoCloseable

    • setName

      public void setName(String name)
      Sets the name of the notifier. Used for debugging purposes only.
      Parameters:
      name - Name

    • setCallback

      public void setCallback(Runnable callback)
      Change the callback function.
      Parameters:
      callback - The callback function.

    • startSingle

      public void startSingle(double delay)
      Run the callback once after the given delay.
      Parameters:
      delay - Time in seconds to wait before the callback is called.

    • startSingle

      public void startSingle(Time delay)
      Run the callback once after the given delay.
      Parameters:
      delay - Time to wait before the callback is called.

    • startPeriodic

      public void startPeriodic(double period)
      Run the callback periodically with the given period.

      The user-provided callback should be written so that it completes before the next time it's scheduled to run.

      Parameters:
      period - Period in seconds after which to call the callback starting one period after the call to this method.

    • startPeriodic

      public void startPeriodic(Time period)
      Run the callback periodically with the given period.

      The user-provided callback should be written so that it completes before the next time it's scheduled to run.

      Parameters:
      period - Period after which to call the callback starting one period after the call to this method.

    • startPeriodic

      public void startPeriodic(Frequency frequency)
      Run the callback periodically with the given frequency.

      The user-provided callback should be written so that it completes before the next time it's scheduled to run.

      Parameters:
      frequency - Frequency at which to call the callback, starting one period after the call to this method.

    • stop

      public void stop()
      Stop further callback invocations.

      No further periodic callbacks will occur. Single invocations will also be cancelled if they haven't yet occurred.

    • setHALThreadPriority

      public static boolean setHALThreadPriority(boolean realTime, int priority)
      Sets the HAL notifier thread priority.

      The HAL notifier thread is responsible for managing the FPGA's notifier interrupt and waking up user's Notifiers when it's their time to run. Giving the HAL notifier thread real-time priority helps ensure the user's real-time Notifiers, if any, are notified to run in a timely manner.

      Parameters:
      realTime - Set to true to set a real-time priority, false for standard priority.
      priority - Priority to set the thread to. For real-time, this is 1-99 with 99 being highest. For non-real-time, this is forced to 0. See "man 7 sched" for more details.
      Returns:
      True on success.