Class ElasticWait

java.lang.Object

io.perl.api.impl.ElasticWait

@NotThreadSafe
public final class ElasticWait
extends Object

Adapts the number of idle parks between wall-clock checks.

The first clock check is deliberately made after one park. Subsequent checks use the observed number of completed parks per millisecond instead of assuming that LockSupport.parkNanos(long) sleeps for exactly the requested duration. This makes the calibration independent of operating system timer granularity, scheduler behavior, CPU speed, and virtual versus platform thread execution.

This class is owned exclusively by the single PerL consumer thread.

Constructor Summary

Constructors

Constructor	Description
ElasticWait(int idleNS, int windowIntervalMS, int minIntervalMS)	Constructor ElasticWait initialize all values.

Method Summary

Modifier and Type	Method	Description
void	reset()	Starts a new reporting window while retaining the measured park rate.
void	setElastic(long currentIntervalMS)	Completes calibration for an expired window and starts the next window.
void	updateElastic(long elapsedIntervalMS)	Updates calibration after a clock check within the current window.
boolean	waitAndCheck()	Parks once and checks whether the next wall-clock sample is due.

Methods inherited from class Object

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

Constructor Details

ElasticWait

public ElasticWait(int idleNS,
 int windowIntervalMS,
 int minIntervalMS)

Constructor ElasticWait initialize all values.

Parameters:

idleNS - requested idle park duration in nanoseconds

windowIntervalMS - reporting-window duration in milliseconds

minIntervalMS - maximum bootstrap calibration interval in milliseconds

Throws:

IllegalArgumentException - if any argument is zero or negative

Method Details

reset

public void reset()

Starts a new reporting window while retaining the measured park rate.

waitAndCheck

public boolean waitAndCheck()

Parks once and checks whether the next wall-clock sample is due.

Returns:

true when the calibrated number of parks has completed

updateElastic

public void updateElastic(long elapsedIntervalMS)

Updates calibration after a clock check within the current window.

The completed batch is always cleared. If the clock has not advanced far enough to measure a rate, the bootstrap batch grows exponentially up to the configured calibration interval. Otherwise the next clock check is scheduled for the remaining part of the reporting window.

Parameters:

elapsedIntervalMS - elapsed milliseconds in the current window

setElastic

public void setElastic(long currentIntervalMS)

Completes calibration for an expired window and starts the next window.

Parameters:

currentIntervalMS - elapsed milliseconds in the expired window