org.jcsp.lang
Class SpuriousLog

java.lang.Object
  org.jcsp.lang.SpuriousLog

public class SpuriousLog
extends Object

This holds the log of spurious wakeups and early timeouts.

Description

The java.lang.Object.wait method sometimes returns spuriously - i.e. without being notify'd by another thread or interrupted or timed-out! This class is an optional (static) repository holding and reporting counts of any such spurious wakeups. JCSP handles all spurious wakeups cleanly.

Some JVMs also timeout on calls of wait(timeout) early. This class enables the specification of how early will be acceptable to JCSP. ``Timeouts'' returned earlier than the set threshold are treated as spurious wakeups (i.e. the process is put back to sleep). Provision is also made for counting and reporting the accepted early timeouts.

To operate, this logging must first be switched on (start()).

Author:

P.H. Welch

Field Summary

static int	AlternativeSelect This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	AlternativeSelectWithTimeout This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	AltingBarrierCoordinateStartEnable This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	Any2AnyChannelIntRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	Any2AnyChannelIntWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	Any2AnyChannelIntXRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	Any2AnyChannelIntXWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	Any2AnyChannelRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	Any2AnyChannelWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	Any2AnyChannelXRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	Any2AnyChannelXWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	Any2OneChannelIntRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	Any2OneChannelIntWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	Any2OneChannelIntXRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	Any2OneChannelIntXWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	Any2OneChannelRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	Any2OneChannelWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	Any2OneChannelXRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	Any2OneChannelXWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	BarrierSync This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	BucketFallInto This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	One2AnyChannelIntRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	One2AnyChannelIntWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	One2AnyChannelIntXRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	One2AnyChannelIntXWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	One2AnyChannelRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	One2AnyChannelWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	One2AnyChannelXRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	One2AnyChannelXWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	One2OneChannelIntRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	One2OneChannelIntWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	One2OneChannelIntXRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	One2OneChannelIntXWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	One2OneChannelRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	One2OneChannelWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	One2OneChannelXRead This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.
static int	One2OneChannelXWrite This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.
static int	StopRun This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

Method Summary

static void	finish() Finish logging of spurious wakeups.
static long	getEarlyTimeout() This returns the allowed early timeout (in msecs).
static int[]	getSpuriousWakeUpCounts() Returns the counts of spurious wakeups so far.
static int	numberEarlyTimeouts() Returns the number of early timeouts accepted so far.
static int	numberSpuriousWakeUps() Returns the number of spurious wakeups so far.
static String	report() This returns a report on the counts of spurious wakeups and early timeouts so far.
static void	setEarlyTimeout(long earlyTimeout) This sets the allowed early timeout (in msecs).
static void	start() Start logging of spurious wakeups.

Methods inherited from class java.lang.Object

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

Field Detail

One2OneChannelIntRead

public static final int One2OneChannelIntRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

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Constant Field Values

One2OneChannelIntWrite

public static final int One2OneChannelIntWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

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Constant Field Values

One2OneChannelIntXRead

public static final int One2OneChannelIntXRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

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Constant Field Values

One2OneChannelIntXWrite

public static final int One2OneChannelIntXWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

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Constant Field Values

One2OneChannelRead

public static final int One2OneChannelRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

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Constant Field Values

One2OneChannelWrite

public static final int One2OneChannelWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

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Constant Field Values

One2OneChannelXRead

public static final int One2OneChannelXRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

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Constant Field Values

One2OneChannelXWrite

public static final int One2OneChannelXWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

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Constant Field Values

Any2OneChannelIntRead

public static final int Any2OneChannelIntRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

See Also:

Constant Field Values

Any2OneChannelIntWrite

public static final int Any2OneChannelIntWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

See Also:

Constant Field Values

Any2OneChannelIntXRead

public static final int Any2OneChannelIntXRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

See Also:

Constant Field Values

Any2OneChannelIntXWrite

public static final int Any2OneChannelIntXWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

See Also:

Constant Field Values

Any2OneChannelRead

public static final int Any2OneChannelRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

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Constant Field Values

Any2OneChannelWrite

public static final int Any2OneChannelWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

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Constant Field Values

Any2OneChannelXRead

public static final int Any2OneChannelXRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

See Also:

Constant Field Values

Any2OneChannelXWrite

public static final int Any2OneChannelXWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

See Also:

Constant Field Values

One2AnyChannelIntRead

public static final int One2AnyChannelIntRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

See Also:

Constant Field Values

One2AnyChannelIntWrite

public static final int One2AnyChannelIntWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

See Also:

Constant Field Values

One2AnyChannelIntXRead

public static final int One2AnyChannelIntXRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

See Also:

Constant Field Values

One2AnyChannelIntXWrite

public static final int One2AnyChannelIntXWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

See Also:

Constant Field Values

One2AnyChannelRead

public static final int One2AnyChannelRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

See Also:

Constant Field Values

One2AnyChannelWrite

public static final int One2AnyChannelWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

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Constant Field Values

One2AnyChannelXRead

public static final int One2AnyChannelXRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

See Also:

Constant Field Values

One2AnyChannelXWrite

public static final int One2AnyChannelXWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

See Also:

Constant Field Values

Any2AnyChannelIntRead

public static final int Any2AnyChannelIntRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

See Also:

Constant Field Values

Any2AnyChannelIntWrite

public static final int Any2AnyChannelIntWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

See Also:

Constant Field Values

Any2AnyChannelIntXRead

public static final int Any2AnyChannelIntXRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

See Also:

Constant Field Values

Any2AnyChannelIntXWrite

public static final int Any2AnyChannelIntXWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

See Also:

Constant Field Values

Any2AnyChannelRead

public static final int Any2AnyChannelRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

See Also:

Constant Field Values

Any2AnyChannelWrite

public static final int Any2AnyChannelWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

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Constant Field Values

Any2AnyChannelXRead

public static final int Any2AnyChannelXRead

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

See Also:

Constant Field Values

Any2AnyChannelXWrite

public static final int Any2AnyChannelXWrite

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

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Constant Field Values

AlternativeSelect

public static final int AlternativeSelect

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

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Constant Field Values

AlternativeSelectWithTimeout

public static final int AlternativeSelectWithTimeout

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

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Constant Field Values

BarrierSync

public static final int BarrierSync

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

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Constant Field Values

BucketFallInto

public static final int BucketFallInto

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

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Constant Field Values

AltingBarrierCoordinateStartEnable

public static final int AltingBarrierCoordinateStartEnable

This indexes the counts of spurious wakeups (getSpuriousWakeUpCounts()), indicating the class and operation that suffered.

Note: this field is not operative in the current JCSP release. Spurious wakeups on AltingBarriers are handled correctly -- just not recorded.

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Constant Field Values

StopRun

public static final int StopRun

This indexes the counts of spurious wakeups (report()), indicating the class and operation that suffered.

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Constant Field Values

Method Detail

start

public static void start()

Start logging of spurious wakeups. This should be set before any concurrency is started. It should only be set once. There is no concurrency protection!

finish

public static void finish()

Finish logging of spurious wakeups. This should be set after any concurrency has finished. There is no concurrency protection!

numberSpuriousWakeUps

public static int numberSpuriousWakeUps()

Returns the number of spurious wakeups so far.

Returns:

the number of spurious wakeups so far.

getSpuriousWakeUpCounts

public static int[] getSpuriousWakeUpCounts()

Returns the counts of spurious wakeups so far. This array is indexed by the public constants in this class. Only a clone is returned.

Returns:

the counts of spurious wakeups so far.

setEarlyTimeout

public static void setEarlyTimeout(long earlyTimeout)

This sets the allowed early timeout (in msecs). Some JVMs timeout on calls of wait(timeout) early - this specifies how early JCSP will tolerate. ``Timeouts'' returned earlier than the set threshold are treated as spurious wakeups (i.e. the process is put back to sleep).

This should be set before any concurrency is started. It should only be set once. There is no concurrency protection!

Parameters:

earlyTimeout - the allowed early timeout (in msecs).

getEarlyTimeout

public static long getEarlyTimeout()

This returns the allowed early timeout (in msecs).

Returns:

the allowed early timeout (in msecs).

numberEarlyTimeouts

public static int numberEarlyTimeouts()

Returns the number of early timeouts accepted so far.

Returns:

the number of early timeouts accepted so far.

report

public static String report()

This returns a report on the counts of spurious wakeups and early timeouts so far. A breakdown of spurious wakeup counts is given only if there are some.

Returns:

the report.