edu.umd.cs.findbugs.ba

Class LockSet

java.lang.Object

edu.umd.cs.findbugs.ba.LockSet

public final class LockSet
extends java.lang.Object

Lock counts for values (as produced by ValueNumberAnalysis). A LockSet tells us the lock counts for all values in a method, insofar as we can accurately determine them.

Author:

David Hovemeyer

See Also:

ValueNumberAnalysis

Field Summary

Fields

Modifier and Type	Field and Description
static int	BOTTOM An invalid lock count resulting from the meet of two different (inconsistent) lock counts.
static int	TOP An uninitialized lock value.

Constructor Summary

Constructors

Constructor and Description
LockSet() Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	clear() Clear all entries out of this LockSet.
boolean	containsReturnValue(ValueNumberFactory factory) Determine whether or not this lock set contains any locked values which are method return values.
void	copyFrom(LockSet other) Make this LockSet the same as the given one.
int	getLockCount(int valueNumber) Get the lock count for given lock object.
java.util.Collection<ValueNumber>	getLockedValueNumbers(ValueNumberFrame frame)
int	getNumLockedObjects() Get the number of distinct lock values with positive lock counts.
void	intersectWith(LockSet other) Destructively intersect this lock set with another.
boolean	isEmpty() Return whether or not this lock set is empty, meaning that no locks have a positive lock count.
boolean	isTop()
void	meetWith(LockSet other) Meet this LockSet with another LockSet, storing the result in this object.
boolean	sameAs(LockSet other) Return whether or not this LockSet is the same as the one given.
void	setDefaultLockCount(int defaultLockCount) Set the default lock count to return for nonexistent lock entries.
void	setLockCount(int valueNumber, int lockCount) Set the lock count for a lock object.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

TOP

public static final int TOP

An uninitialized lock value.

See Also:

Constant Field Values

BOTTOM

public static final int BOTTOM

An invalid lock count resulting from the meet of two different (inconsistent) lock counts.

See Also:

Constant Field Values

Constructor Detail

LockSet

public LockSet()

Constructor. Creates an empty lock set which returns TOP for nonexistent lock entries.

Method Detail

getLockCount

public int getLockCount(int valueNumber)

Get the lock count for given lock object.

Parameters:

valueNumber - value number of the lock object

Returns:

the lock count for the lock object

isTop

public boolean isTop()

setLockCount

public void setLockCount(int valueNumber,
                int lockCount)

Set the lock count for a lock object.

Parameters:

valueNumber - value number of the lock object

lockCount - the lock count for the lock

setDefaultLockCount

public void setDefaultLockCount(int defaultLockCount)

Set the default lock count to return for nonexistent lock entries.

Parameters:

defaultLockCount - the default lock count value

getNumLockedObjects

public int getNumLockedObjects()

Get the number of distinct lock values with positive lock counts.

copyFrom

public void copyFrom(LockSet other)

Make this LockSet the same as the given one.

Parameters:

other - the LockSet to copy

clear

public void clear()

Clear all entries out of this LockSet.

meetWith

public void meetWith(LockSet other)

Meet this LockSet with another LockSet, storing the result in this object.

Parameters:

other - the other LockSet

sameAs

public boolean sameAs(LockSet other)

Return whether or not this LockSet is the same as the one given.

Parameters:

other - the other LockSet

containsReturnValue

public boolean containsReturnValue(ValueNumberFactory factory)

Determine whether or not this lock set contains any locked values which are method return values.

Parameters:

factory - the ValueNumberFactory that produced the lock values

intersectWith

public void intersectWith(LockSet other)

Destructively intersect this lock set with another. Note that this is not a dataflow merge: we are interested in finding out which locks are held in both sets, not in the exact lock counts.

Parameters:

other - the other LockSet

isEmpty

public boolean isEmpty()

Return whether or not this lock set is empty, meaning that no locks have a positive lock count.

Returns:

true if no locks are held, false if at least one lock is held

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getLockedValueNumbers

public java.util.Collection<ValueNumber> getLockedValueNumbers(ValueNumberFrame frame)

Parameters:

frame -

Returns:

a set of the locked value numbers