org.agrona.concurrent

Class BackoffIdleStrategy

java.lang.Object

org.agrona.concurrent.BackoffIdleStrategy

All Implemented Interfaces:

IdleStrategy

public final class BackoffIdleStrategy
extends java.lang.Object
implements IdleStrategy

Field Summary

Fields

Modifier and Type	Field and Description
protected long	maxParkPeriodNs
protected long	maxSpins
protected long	maxYields
protected long	minParkPeriodNs
protected long	parkPeriodNs
protected long	spins
protected org.agrona.concurrent.BackoffIdleStrategyData.State	state
protected long	yields

Constructor Summary

Constructors

Constructor and Description
BackoffIdleStrategy(long maxSpins, long maxYields, long minParkPeriodNs, long maxParkPeriodNs) Create a set of state tracking idle behavior

Method Summary

Modifier and Type	Method and Description
void	idle() Perform current idle action (e.g.
void	idle(int workCount) Perform current idle action (e.g.
void	reset() Reset the internal state in preparation for entering an idle state again.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

maxSpins

protected final long maxSpins

maxYields

protected final long maxYields

minParkPeriodNs

protected final long minParkPeriodNs

maxParkPeriodNs

protected final long maxParkPeriodNs

state

protected org.agrona.concurrent.BackoffIdleStrategyData.State state

spins

protected long spins

yields

protected long yields

parkPeriodNs

protected long parkPeriodNs

Constructor Detail

BackoffIdleStrategy

public BackoffIdleStrategy(long maxSpins,
                           long maxYields,
                           long minParkPeriodNs,
                           long maxParkPeriodNs)

Create a set of state tracking idle behavior

Parameters:

maxSpins - to perform before moving to Thread.yield()

maxYields - to perform before moving to LockSupport.parkNanos(long)

minParkPeriodNs - to use when initiating parking

maxParkPeriodNs - to use when parking

Method Detail

idle

public void idle(int workCount)

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()

Description copied from interface: IdleStrategy

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()

Description copied from interface: IdleStrategy

Reset the internal state in preparation for entering an idle state again.

Specified by:

reset in interface IdleStrategy