org.apache.solr.hadoop
Class HeartBeater

java.lang.Object
  java.lang.Thread
      org.apache.solr.hadoop.HeartBeater

All Implemented Interfaces:

Runnable

public class HeartBeater
extends Thread

This class runs a background thread that once every 60 seconds checks to see if a progress report is needed. If a report is needed it is issued. A simple counter threadsNeedingHeartBeat handles the number of threads requesting a heart beat. The expected usage pattern is

  try {
       heartBeater.needHeartBeat();
       do something that may take a while
    } finally {
       heartBeater.cancelHeartBeat();
    }
 

Nested Class Summary

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

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

static org.slf4j.Logger

LOG

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

HeartBeater(org.apache.hadoop.util.Progressable progress)
Create the heart beat object thread set it to daemon priority and start the thread.

Method Summary

void	cancelHeartBeat() inform the background thread that this heartbeat request is not needed.
void	close() Releases any resources
org.apache.hadoop.util.Progressable	getProgress()
void	needHeartBeat() inform the background thread that heartbeats are to be issued.
void	run()
void	setProgress(org.apache.hadoop.util.Progressable progress)
void	setStatus(String status)

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

Field Detail

LOG

public static org.slf4j.Logger LOG

Constructor Detail

HeartBeater

public HeartBeater(org.apache.hadoop.util.Progressable progress)

Create the heart beat object thread set it to daemon priority and start the thread. When the count in threadsNeedingHeartBeat is positive, the heart beat will be issued on the progress object every 60 seconds.

Method Detail

getProgress

public org.apache.hadoop.util.Progressable getProgress()

setProgress

public void setProgress(org.apache.hadoop.util.Progressable progress)

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

needHeartBeat

public void needHeartBeat()

inform the background thread that heartbeats are to be issued. Issue a heart beat also

cancelHeartBeat

public void cancelHeartBeat()

inform the background thread that this heartbeat request is not needed. This must be called at some point after each needHeartBeat() request.

setStatus

public void setStatus(String status)

close

public void close()

Releases any resources