com.sleepycat.je.evictor

Class Evictor

java.lang.Object

com.sleepycat.je.utilint.DaemonThread

com.sleepycat.je.evictor.Evictor

All Implemented Interfaces:

DaemonRunner, java.lang.Runnable

public class Evictor
extends DaemonThread

The Evictor looks through the INList for IN's and BIN's that are worthy of eviction. Once the nodes are selected, it removes all references to them so that they can be GC'd by the JVM.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Evictor.EvictProfile

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	SOURCE_CRITICAL
static java.lang.String	SOURCE_DAEMON
static java.lang.String	SOURCE_MANUAL

Fields inherited from class com.sleepycat.je.utilint.DaemonThread

name, nWakeupRequests, stifleExceptionChatter, workQueue, workQueueLatch

Constructor Summary

Constructors

Constructor and Description
Evictor(EnvironmentImpl envImpl, java.lang.String name)

Method Summary

Methods

Modifier and Type	Method and Description
void	addToQueue(java.lang.Object o) Evictor doesn't have a work queue so just throw an exception if it's ever called.
void	alert() Wakeup the evictor only if it's not already active.
void	clearEnv()
void	doCriticalEviction(boolean backgroundIO) Do a check on whether synchronous eviction is needed.
void	doEvict(java.lang.String source) May be called by the evictor thread on wakeup or programatically.
void	loadStats(StatsConfig config, EnvironmentStats stat) Load stats.
protected int	nDeadlockRetries() Return the number of retries when a deadlock exception occurs.
int	normalizeLevel(IN in, int evictType) Normalize the tree level of the given IN.
void	onWakeup() Called whenever the daemon thread wakes up from a sleep.
void	setRunnableHook(TestHook hook)

Methods inherited from class com.sleepycat.je.utilint.DaemonThread

addToQueueAlreadyLatched, getNWakeupRequests, getQueueSize, getThread, isPaused, isRunning, isShutdownRequested, requestShutdown, run, runOrPause, shutdown, toString, wakeup

Methods inherited from class java.lang.Object

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

Field Detail

SOURCE_DAEMON

public static final java.lang.String SOURCE_DAEMON

See Also:

Constant Field Values

SOURCE_MANUAL

public static final java.lang.String SOURCE_MANUAL

See Also:

Constant Field Values

SOURCE_CRITICAL

public static final java.lang.String SOURCE_CRITICAL

See Also:

Constant Field Values

Constructor Detail

Evictor

public Evictor(EnvironmentImpl envImpl,
       java.lang.String name)
        throws DatabaseException

Throws:

DatabaseException

Method Detail

addToQueue

public void addToQueue(java.lang.Object o)
                throws DatabaseException

Evictor doesn't have a work queue so just throw an exception if it's ever called.

Overrides:

addToQueue in class DaemonThread

Throws:

DatabaseException

loadStats

public void loadStats(StatsConfig config,
             EnvironmentStats stat)
               throws DatabaseException

Load stats.

Throws:

DatabaseException

clearEnv

public void clearEnv()

nDeadlockRetries

protected int nDeadlockRetries()
                        throws DatabaseException

Return the number of retries when a deadlock exception occurs.

Overrides:

nDeadlockRetries in class DaemonThread

Throws:

DatabaseException

alert

public void alert()

Wakeup the evictor only if it's not already active.

onWakeup

public void onWakeup()
              throws DatabaseException

Called whenever the daemon thread wakes up from a sleep.

Specified by:

onWakeup in class DaemonThread

Throws:

DatabaseException

doEvict

public void doEvict(java.lang.String source)
             throws DatabaseException

May be called by the evictor thread on wakeup or programatically.

Throws:

DatabaseException

doCriticalEviction

public void doCriticalEviction(boolean backgroundIO)
                        throws DatabaseException

Do a check on whether synchronous eviction is needed.

Throws:

DatabaseException

normalizeLevel

public int normalizeLevel(IN in,
                 int evictType)

Normalize the tree level of the given IN. Is public for unit testing. A BIN containing evictable LNs is given level 0, so it will be stripped first. For non-duplicate and DBMAP trees, the high order bits are cleared to make their levels correspond; that way, all bottom level nodes (BINs and DBINs) are given the same eviction priority. Note that BINs in a duplicate tree are assigned the same level as BINs in a non-duplicate tree. This isn't always optimimal, but is the best we can do considering that BINs in duplicate trees may contain a mix of LNs and DINs. BINs in the mapping tree are also assigned the same level as user DB BINs. When doing by-level eviction (lruOnly=false), this seems counter-intuitive since we should evict user DB nodes before mapping DB nodes. But that does occur because mapping DB INs referencing an open DB are unevictable. The level is only used for selecting among evictable nodes. If we did NOT normalize the level for the mapping DB, then INs for closed evictable DBs would not be evicted until after all nodes in all user DBs were evicted. If there were large numbers of closed DBs, this would have a negative performance impact.

setRunnableHook

public void setRunnableHook(TestHook hook)