Class NoOpIdleStrategy

  • All Implemented Interfaces:
    IdleStrategy

    public final class NoOpIdleStrategy
    extends java.lang.Object
    implements IdleStrategy
    Low-latency idle strategy to be employed in loops that do significant work on each iteration such that any work in the idle strategy would be wasteful.
    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.String ALIAS
      Name to be returned from alias().
      static NoOpIdleStrategy INSTANCE
      As there is no instance state then this object can be used to save on allocation.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String alias()
      Simple name by which the strategy can be identified.
      void idle()
      Note: this implementation will result in no safepoint poll once inlined.
      void idle​(int workCount)
      Note: this implementation will result in no safepoint poll once inlined.
      void reset()
      Reset the internal state in preparation for entering an idle state again.
      java.lang.String toString()
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Field Detail

      • INSTANCE

        public static final NoOpIdleStrategy INSTANCE
        As there is no instance state then this object can be used to save on allocation.
    • Constructor Detail

      • NoOpIdleStrategy

        public NoOpIdleStrategy()
    • Method Detail

      • idle

        public void idle​(int workCount)
        Note: this implementation will result in no safepoint poll once inlined.

        Perform current idle action (e.g. nothing/yield/sleep). This method signature expects users to call into it on every work 'cycle'. The implementations may use the indication "workCount > 0" to reset internal backoff state. This method works well with 'work' APIs which follow the following rules:

        • 'work' returns a value larger than 0 when some work has been done
        • 'work' returns 0 when no work has been done
        • 'work' may return error codes which are less than 0, but which amount to no work has been done

        Callers are expected to follow this pattern:

         
         while (isRunning)
         {
             idleStrategy.idle(doWork());
         }
         
         
        Specified by:
        idle in interface IdleStrategy
        Parameters:
        workCount - performed in last duty cycle.
      • idle

        public void idle()
        Note: this implementation will result in no safepoint poll once inlined.

        Perform current idle action (e.g. nothing/yield/sleep). To be used in conjunction with IdleStrategy.reset() to clear internal state when idle period is over (or before it begins). Callers are expected to follow this pattern:

         
         while (isRunning)
         {
           if (!hasWork())
           {
             idleStrategy.reset();
             while (!hasWork())
             {
               if (!isRunning)
               {
                 return;
               }
               idleStrategy.idle();
             }
           }
           doWork();
         }
         
         
        Specified by:
        idle in interface IdleStrategy
      • reset

        public void reset()
        Reset the internal state in preparation for entering an idle state again.
        Specified by:
        reset in interface IdleStrategy
      • alias

        public java.lang.String alias()
        Simple name by which the strategy can be identified.
        Specified by:
        alias in interface IdleStrategy
        Returns:
        simple name by which the strategy can be identified.
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object