org.LatencyUtils
Class SimplePauseDetector

java.lang.Object
  java.lang.Thread
      org.LatencyUtils.PauseDetector
          org.LatencyUtils.SimplePauseDetector

All Implemented Interfaces:

Runnable

public class SimplePauseDetector
extends PauseDetector

A Simple PauseDetector that detects pauses using a consensus observation across a configurable number of detection thread. Detection threads can be set to periodically wakeup or continually spin.

All times and time units are in nanoseconds

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

SimplePauseDetector()
Creates a SimplePauseDetector with a default sleep interval (1 msec), a default pause notification threshold (1 msec), and using the default number of consensus detection threads (3).

SimplePauseDetector(long sleepInterval, long pauseNotificationThreshold, int numberOfDetectorThreads)
Creates a SimplePauseDetector

SimplePauseDetector(long sleepInterval, long pauseNotificationThreshold, int numberOfDetectorThreads, boolean verbose)
Creates a SimplePauseDetector

Method Summary

void	shutdown() Shut down the pause detector operation and terminate it's threads.
void	skipConsensusTimeTo(long newConsensusTime) A test method that allows the caller to artificially move the consensus observed time forward without causing a pause to be detected as a result of the time skip.
void	stallDetectorThreads(long threadNumberMask, long stallLength) A test method that allows the caller to artificially stall a requested set of the detector threads for a given amount of time.

Methods inherited from class org.LatencyUtils.PauseDetector

addListener, addListener, notifyListeners, removeListener, run

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Constructor Detail

SimplePauseDetector

public SimplePauseDetector(long sleepInterval,
                           long pauseNotificationThreshold,
                           int numberOfDetectorThreads)

Creates a SimplePauseDetector

Parameters:

sleepInterval - sleep interval used by detector threads

pauseNotificationThreshold - minimum threshold for reporting detected pauses

numberOfDetectorThreads - number of consensus detector threads to use

SimplePauseDetector

public SimplePauseDetector(long sleepInterval,
                           long pauseNotificationThreshold,
                           int numberOfDetectorThreads,
                           boolean verbose)

Creates a SimplePauseDetector

Parameters:

sleepInterval - sleep interval used by detector threads

pauseNotificationThreshold - minimum threshold for reporting detected pauses

numberOfDetectorThreads - number of consensus detector threads to use

verbose - provide verbose output when pauses are detected

SimplePauseDetector

public SimplePauseDetector()

Creates a SimplePauseDetector with a default sleep interval (1 msec), a default pause notification threshold (1 msec), and using the default number of consensus detection threads (3).

Method Detail

shutdown

public void shutdown()

Shut down the pause detector operation and terminate it's threads.

Overrides:

shutdown in class PauseDetector

stallDetectorThreads

public void stallDetectorThreads(long threadNumberMask,
                                 long stallLength)
                          throws InterruptedException

A test method that allows the caller to artificially stall a requested set of the detector threads for a given amount of time. Used to verify pause detection when consensus occurs, as well as lack of detection when it does not.

Parameters:

threadNumberMask - a mask designating which threads should be stalled.

stallLength - stall length, in nanosecond units

Throws:

InterruptedException

skipConsensusTimeTo

public void skipConsensusTimeTo(long newConsensusTime)

A test method that allows the caller to artificially move the consensus observed time forward without causing a pause to be detected as a result of the time skip. Useful for test programs that wish to use artificial time services.

Parameters:

newConsensusTime -