Class AbbaLockingDetector

java.lang.Object

org.h2.util.AbbaLockingDetector

All Implemented Interfaces:

Runnable

public class AbbaLockingDetector
extends Object
implements Runnable

Utility to detect AB-BA deadlocks.

Field Summary

Fields

Modifier and Type	Field	Description
private final Set<String>	knownDeadlocks
private final Map<String, Map<String,String>>	lockOrdering	Map of (object A) -> ( map of (object locked before object A) -> (stack trace where locked) )
private boolean	stop
private Thread	thread
private final ThreadMXBean	threadMXBean
private final int	tickIntervalMs

Constructor Summary

Constructors

Constructor	Description
AbbaLockingDetector()

Method Summary

Modifier and Type	Method	Description
private static void	dumpStackTraceElement(ThreadInfo info, StringBuilder sb, int i, StackTraceElement e)
private static void	generateOrdering(List<String> lockOrder, ThreadInfo info)	We cannot simply call getLockedMonitors because it is not guaranteed to return the locks in the correct order.
private static String	getObjectName(MonitorInfo info)
private static String	getStackTraceForThread(ThreadInfo info)	Dump data in the same format as ThreadInfo.toString(), but with some modifications (no stack frame limit, and removal of uninteresting stack frames)
private void	markHigher(List<String> lockOrder, ThreadInfo threadInfo)
private void	processThreadList(ThreadInfo[] threadInfoList)
void	reset()	Reset the state.
void	run()
AbbaLockingDetector	startCollecting()	Start collecting locking data.
AbbaLockingDetector	stopCollecting()	Stop collecting.
private void	tick()

Methods inherited from class Object

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

Field Details

tickIntervalMs

private final int tickIntervalMs

See Also:

• Constant Field Values

stop

private volatile boolean stop

threadMXBean

private final ThreadMXBean threadMXBean

thread

private Thread thread

lockOrdering

private final Map<String, Map<String,String>> lockOrdering

Map of (object A) -> ( map of (object locked before object A) -> (stack trace where locked) )

knownDeadlocks

private final Set<String> knownDeadlocks

Constructor Details

AbbaLockingDetector

public AbbaLockingDetector()

Method Details

startCollecting

public AbbaLockingDetector startCollecting()

Start collecting locking data.

Returns:

this

reset

public void reset()

Reset the state.

stopCollecting

public AbbaLockingDetector stopCollecting()

Stop collecting.

Returns:

this

run

public void run()

Specified by:

run in interface Runnable

tick

private void tick()

processThreadList

private void processThreadList(ThreadInfo[] threadInfoList)

generateOrdering

private static void generateOrdering(List<String> lockOrder,
 ThreadInfo info)

We cannot simply call getLockedMonitors because it is not guaranteed to return the locks in the correct order.

markHigher

private void markHigher(List<String> lockOrder,
 ThreadInfo threadInfo)

getStackTraceForThread

private static String getStackTraceForThread(ThreadInfo info)

Dump data in the same format as ThreadInfo.toString(), but with some modifications (no stack frame limit, and removal of uninteresting stack frames)

dumpStackTraceElement

private static void dumpStackTraceElement(ThreadInfo info,
 StringBuilder sb,
 int i,
 StackTraceElement e)

getObjectName

private static String getObjectName(MonitorInfo info)