org.agrona.concurrent

Class NoOpIdleStrategy

java.lang.Object

org.agrona.concurrent.NoOpIdleStrategy

All Implemented Interfaces:

IdleStrategy

public final class NoOpIdleStrategy
extends 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 and Description
static 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.

Constructor Summary

Constructors

Constructor and Description
NoOpIdleStrategy()

Method Summary

Modifier and Type	Method and Description
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.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

ALIAS

public static final String ALIAS

Name to be returned from alias().

See Also:

Constant Field Values

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 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 String toString()

Overrides:

toString in class Object