Class GuardSupport

java.lang.Object

com.tangosol.util.Base

com.tangosol.net.GuardSupport

public class GuardSupport
extends Base

A concrete implementation of Guardian/Guardable interactions. GuardSupport is used by a Guardian to manage its responsibilities.

Since:

Coherence 3.5

Author:

rhl

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	GuardSupport.Context	Base implementation for GuardContext's used by GuardSupport.

Nested classes/interfaces inherited from class com.tangosol.util.Base

Base.LoggingWriter

Field Summary

Fields

Modifier and Type	Field	Description
protected static final String	DEFAULT_LOG_THREADDUMP_INTERVAL	Default guardian log thread dump interval as a time duration.
protected static final long	GUARDIAN_EARLY_THRESHOLD	The threshold before which than which a guardian considers itself early in checking its guardables.
protected static final long	GUARDIAN_LATE_THRESHOLD	The threshold past which a guardian considers itself late in checking its guardables.
static final long	GUARDIAN_MAX_CHECK_INTERVAL	The maximum interval at which the Guardian thread should call check() to verify its guardables.
protected static final long	LOG_THREADDUMP_INTERVAL_MS	The minimum interval at which the Guardian should log thread dumps in milliseconds.
protected GuardSupport.Context[]	m_aGuardContext	Array of GuardContexts for the registered Guardables.
protected int	m_cGuardable	The number of registered Guardables.
protected Guardian	m_guardian	The Guardian that is managing this GuardSupport.
protected long	m_ldtNextCheck	The next time at which the Guardables should be checked.
protected static ThreadLocal	m_tlContext	ThreadLocal containing the GuardContext associated with the current thread.
protected static final String	MAX_LOG_THREADDUMP_INTERVAL
protected static final long	MAX_LOG_THREADDUMP_INTERVAL_MS	Max interval in milliseconds at which the Guardian log thread dump interval can be configured.
protected static final String	PROP_LOG_THREADDUMP_INTERVAL	Property for configuring minimum Guardian log thread dump interval as a time duration.
protected static AtomicLong	s_atomicLogTime	Atomic counter containing the last log time stamp.

Fields inherited from class com.tangosol.util.Base

DEFAULT_LOAD_FACTOR, LOG_ALWAYS, LOG_CONFIG, LOG_DEBUG, LOG_ERR, LOG_INFO, LOG_MAX, LOG_MIN, LOG_QUIET, LOG_WARN, POWER_0, POWER_G, POWER_K, POWER_M, POWER_T, UNIT_D, UNIT_H, UNIT_M, UNIT_MS, UNIT_NS, UNIT_S, UNIT_US

Constructor Summary

Constructors

Constructor	Description
GuardSupport(Guardian guardian)	Construct a GuardSupport for the specified Guardian.

Method Summary

Modifier and Type	Method	Description
Guardian.GuardContext	add(Guardable guardable, long cMillis, float flPctRecover)	Add the specified guardable to the set of Guardables managed by this manager, subject to the specified service parameters.
long	check()	Check the registered Guardable objects for timeout, taking appropriate action and calculate the timestamp when the next check should be performed.
int	getGuardableCount()	Return the number of Guardables that are registered with this GuardSupport.
protected GuardSupport.Context[]	getGuardContexts()	Return the array of GuardContext objects for the Guardables managed by this GuardSupport.
protected Guardian	getGuardian()	Return the Guardian that manages this GuardSupport.
protected static long	getLogThreaddumpIntervalMs()	Configure guardian log thread dump interval using property PROP_LOG_THREADDUMP_INTERVAL set to a time duration, i.e.
long	getNextCheckTime()	Return the next time at which the Guardables should be checked.
static Guardian.GuardContext	getThreadContext()	Obtain the GuardContext associated with the current thread.
static String	getThreadDump()	Get the full thread dump.
static void	heartbeat()	Issue a heartbeat on the GuardContext associated with the current thread.
static void	heartbeat(long cMillis)	Issue a heartbeat of the specified duration on the GuardContext associated with the current thread.
protected GuardSupport.Context	instantiateContext(Guardable guardable, long cMillis, float flPctRecover)
static void	logStackTraces()	Collect stack traces and synchronization information for all running threads and write them to the error log.
void	release()	Release the Guardables managed by this GuardSupport.
void	remove(Guardable guardable)	Remove the specified Guardable from the set of Guardables managed by this manager.
static void	reset()	Issue a reset on the GuardContext associated with the current thread.
protected void	setGuardableCount(int cGuardable)	Set the number of Guardables that are registered with this GuardSupport.
protected void	setGuardContexts(GuardSupport.Context[] aGuardContext)	Set the array of GuardContext objects for the Guardables that are managed by this GuardSupport.
protected void	setNextCheckTime(long ldtNextCheck)	Set the next time at which the Guardables should be checked.
static void	setThreadContext(Guardian.GuardContext context)	Associate the specified GuardContext with the current thread.

Methods inherited from class com.tangosol.util.Base

azzert, azzert, azzert, azzertFailed, breakLines, breakLines, capitalize, checkNotEmpty, checkNotNull, checkRange, computeSafeWaitTime, decimalValue, dup, dup, ensureBigDecimal, ensureClassLoader, ensureRuntimeException, ensureRuntimeException, equals, equalsDeep, err, err, err, err, err, escape, formatDateTime, getCallerStackFrame, getCommonMonitor, getCommonMonitor, getCommonMonitor, getContextClassLoader, getContextClassLoader, getDeepMessage, getErr, getLastSafeTimeMillis, getLog, getMaxDecDigits, getMaxHexDigits, getOriginalException, getOut, getProcessRandom, getRandom, getRandomBinary, getRandomBinary, getRandomString, getSafeTimeMillis, getStackFrame, getStackFrames, getStackTrace, getStackTrace, getStackTrace, getThreadFactory, getTimeZone, getUpTimeMillis, hashCode, hexValue, indentString, indentString, isDecimal, isHex, isLogEcho, isOctal, log, log, log, log, log, makeInteger, makeLong, makeThread, mergeArray, mergeBooleanArray, mergeByteArray, mergeCharArray, mergeDoubleArray, mergeFloatArray, mergeIntArray, mergeLongArray, mod, mod, newHashMap, newHashMap, newHashSet, newHashSet, octalValue, out, out, out, out, out, pad, parseBandwidth, parseBandwidth, parseDelimitedString, parseHex, parseHex, parseMemorySize, parseMemorySize, parsePercentage, parseTime, parseTime, parseTimeNanos, parseTimeNanos, printStackTrace, randomize, randomize, randomize, randomize, read, read, read, read, read, read, read, replace, setErr, setLog, setLogEcho, setOut, sleep, toBandwidthString, toBandwidthString, toCharEscape, toCrc, toCrc, toCrc, toCrc, toCrc, toDecString, toDelimitedString, toDelimitedString, toDelimitedString, toDelimitedString, toHex, toHex, toHexDump, toHexEscape, toHexEscape, toHexEscape, toHexEscape, toHexString, toMemorySizeString, toMemorySizeString, toQuotedCharEscape, toQuotedStringEscape, toSqlString, toString, toString, toStringEscape, toUnicodeEscape, trace, trace, trace, trace, trace, trace, trace, trace, trace, truncateString, truncateString, wait

Methods inherited from class java.lang.Object

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

Field Details

GUARDIAN_MAX_CHECK_INTERVAL

public static final long GUARDIAN_MAX_CHECK_INTERVAL

The maximum interval at which the Guardian thread should call check() to verify its guardables.

See Also:

• Constant Field Values

GUARDIAN_LATE_THRESHOLD

protected static final long GUARDIAN_LATE_THRESHOLD

The threshold past which a guardian considers itself late in checking its guardables.

See Also:

• Constant Field Values

GUARDIAN_EARLY_THRESHOLD

protected static final long GUARDIAN_EARLY_THRESHOLD

The threshold before which than which a guardian considers itself early in checking its guardables.

See Also:

• Constant Field Values

PROP_LOG_THREADDUMP_INTERVAL

protected static final String PROP_LOG_THREADDUMP_INTERVAL

Property for configuring minimum Guardian log thread dump interval as a time duration. Configure this property to reduce the number of Guardian log thread dumps in logs when too many are occurring over a short duration of time. Format is documented as String parameter of Duration(String).

Since:

25.03

See Also:

• DEFAULT_LOG_THREADDUMP_INTERVAL
• MAX_LOG_THREADDUMP_INTERVAL
• Constant Field Values

DEFAULT_LOG_THREADDUMP_INTERVAL

protected static final String DEFAULT_LOG_THREADDUMP_INTERVAL

Default guardian log thread dump interval as a time duration.

Since:

25.03

See Also:

• Constant Field Values

MAX_LOG_THREADDUMP_INTERVAL

protected static final String MAX_LOG_THREADDUMP_INTERVAL

See Also:

• Constant Field Values

MAX_LOG_THREADDUMP_INTERVAL_MS

protected static final long MAX_LOG_THREADDUMP_INTERVAL_MS

Max interval in milliseconds at which the Guardian log thread dump interval can be configured.

Since:

25.03

LOG_THREADDUMP_INTERVAL_MS

protected static final long LOG_THREADDUMP_INTERVAL_MS

The minimum interval at which the Guardian should log thread dumps in milliseconds. Override default DEFAULT_LOG_THREADDUMP_INTERVAL by setting property PROP_LOG_THREADDUMP_INTERVAL to a time duration.

Since:

25.03

See Also:

• MAX_LOG_THREADDUMP_INTERVAL

m_aGuardContext

protected GuardSupport.Context[] m_aGuardContext

Array of GuardContexts for the registered Guardables. May contain nulls.

m_cGuardable

protected int m_cGuardable

The number of registered Guardables.

m_guardian

protected Guardian m_guardian

The Guardian that is managing this GuardSupport.

m_ldtNextCheck

protected long m_ldtNextCheck

The next time at which the Guardables should be checked.

m_tlContext

protected static ThreadLocal m_tlContext

ThreadLocal containing the GuardContext associated with the current thread.

s_atomicLogTime

protected static AtomicLong s_atomicLogTime

Atomic counter containing the last log time stamp.

Constructor Details

GuardSupport

public GuardSupport(Guardian guardian)

Construct a GuardSupport for the specified Guardian.

Parameters:

guardian - the guardian managing this GuardSupport

Method Details

getGuardContexts

protected GuardSupport.Context[] getGuardContexts()

Return the array of GuardContext objects for the Guardables managed by this GuardSupport.

Returns:

the array of managed GuardContext objects

setGuardContexts

protected void setGuardContexts(GuardSupport.Context[] aGuardContext)

Set the array of GuardContext objects for the Guardables that are managed by this GuardSupport.

Parameters:

aGuardContext - the array of managed GuardContext objects

getGuardian

protected Guardian getGuardian()

Return the Guardian that manages this GuardSupport.

Returns:

the Guardian that manages this GuardSupport

getNextCheckTime

public long getNextCheckTime()

Return the next time at which the Guardables should be checked.

Returns:

the next time at which the Guardables should be checked

setNextCheckTime

protected void setNextCheckTime(long ldtNextCheck)

Set the next time at which the Guardables should be checked.

Parameters:

ldtNextCheck - the next time at which the Guardables should be checked

add

public Guardian.GuardContext add(Guardable guardable,
 long cMillis,
 float flPctRecover)

Add the specified guardable to the set of Guardables managed by this manager, subject to the specified service parameters. If the specified guardable is already guarded by this manager, adjust the service parameters.

Parameters:

guardable - the Guardable object to be managed

cMillis - the timeout for the specified Guardable

flPctRecover - the percentage of the timeout after which to attempt recovery of the Guardable; 0 < flPctRecover <= 1.0

Returns:

the GuardContext for the specified Guardable

remove

public void remove(Guardable guardable)

Remove the specified Guardable from the set of Guardables managed by this manager.

Parameters:

guardable - the guardable to remove

getGuardableCount

public int getGuardableCount()

Return the number of Guardables that are registered with this GuardSupport.

Returns:

the number of registered Guardable objects

setGuardableCount

protected void setGuardableCount(int cGuardable)

Set the number of Guardables that are registered with this GuardSupport.

Parameters:

cGuardable - the number of registered Guardable objects

check

public long check()

Check the registered Guardable objects for timeout, taking appropriate action and calculate the timestamp when the next check should be performed. The next check time can later be retrieved by the getNextCheckTime() method.

Returns:

the number of milliseconds past the time when the guardables should have been checked, or 0 if the check was performed on time

release

public void release()

Release the Guardables managed by this GuardSupport. Releasing a Guardable causes it to no longer be guarded.

instantiateContext

protected GuardSupport.Context instantiateContext(Guardable guardable,
 long cMillis,
 float flPctRecover)

Parameters:

guardable - the Guardable object to be managed

cMillis - the timeout for the specified Guardable

flPctRecover - the percentage of the timeout after which to attempt recovery of the Guardable; 0 < flPctRecover <= 1.0

Returns:

a Context for the specified guardable and SLA parameters

getThreadContext

public static Guardian.GuardContext getThreadContext()

Obtain the GuardContext associated with the current thread.

Returns:

the GuardContext or null if it has not been set

setThreadContext

public static void setThreadContext(Guardian.GuardContext context)

Associate the specified GuardContext with the current thread.

Parameters:

context - the GuardContext to associate with the current thread

heartbeat

public static void heartbeat()

Issue a heartbeat on the GuardContext associated with the current thread.

heartbeat

public static void heartbeat(long cMillis)

Issue a heartbeat of the specified duration on the GuardContext associated with the current thread.

Parameters:

cMillis - the number of milliseconds to heartbeat for

reset

public static void reset()

Issue a reset on the GuardContext associated with the current thread.

logStackTraces

public static void logStackTraces()

Collect stack traces and synchronization information for all running threads and write them to the error log.

getThreadDump

public static String getThreadDump()

Get the full thread dump.

Returns:

a string containing the thread dump

getLogThreaddumpIntervalMs

protected static long getLogThreaddumpIntervalMs()

Configure guardian log thread dump interval using property PROP_LOG_THREADDUMP_INTERVAL set to a time duration, i.e. 15m or 2h. The maximum allowed duration is MAX_LOG_THREADDUMP_INTERVAL, any value provided above this value is treated as the max allowed log thread dump interval. Default duration of DEFAULT_LOG_THREADDUMP_INTERVAL is used when property is not or set to an invalid time duration.

Returns:

the computed guardian log thread dump interval in milliseconds.

Since:

25.03