Package edu.umd.cs.findbugs.ba
Class LockSet
java.lang.Object
edu.umd.cs.findbugs.ba.LockSet
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.
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate int[]
Lock counts are stored in an array.static final int
An invalid lock count resulting from the meet of two different (inconsistent) lock counts.private static final int
private int
The lock count value to return for nonexistent lock entries.private static final int
static final int
An uninitialized lock value. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionprivate void
addEntry
(int negatedIndex, int valueNumber, int lockCount) 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
Make this LockSet the same as the given one.private int
findIndex
(int valueNumber) int
getLockCount
(int valueNumber) Get the lock count for given lock object.int
Get the number of distinct lock values with positive lock counts.private boolean
identicalSubset
(LockSet other) 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
Meet this LockSet with another LockSet, storing the result in this object.private static int
mergeValues
(int a, int b) boolean
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.toString()
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Field Details
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TOP
public static final int TOPAn uninitialized lock value.- See Also:
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BOTTOM
public static final int BOTTOMAn invalid lock count resulting from the meet of two different (inconsistent) lock counts.- See Also:
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INVALID
private static final int INVALID- See Also:
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DEFAULT_CAPACITY
private static final int DEFAULT_CAPACITY- See Also:
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array
private int[] arrayLock counts are stored in an array. Even indices i are value numbers of lock objects. Odd indices i+1 are lock counts. This representation is fairly compact in memory. -
defaultLockCount
private int defaultLockCountThe lock count value to return for nonexistent lock entries.
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Constructor Details
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LockSet
public LockSet()Constructor. Creates an empty lock set which returns TOP for nonexistent lock entries.
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Method Details
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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
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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 objectlockCount
- the lock count for the lock
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setDefaultLockCount
public void setDefaultLockCount(int defaultLockCount) Set the default lock count to return for nonexistent lock entries.- Parameters:
defaultLockCount
- the default lock count value
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getNumLockedObjects
public int getNumLockedObjects()Get the number of distinct lock values with positive lock counts. -
copyFrom
Make this LockSet the same as the given one.- Parameters:
other
- the LockSet to copy
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clear
public void clear()Clear all entries out of this LockSet. -
meetWith
Meet this LockSet with another LockSet, storing the result in this object.- Parameters:
other
- the other LockSet
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sameAs
Return whether or not this LockSet is the same as the one given.- Parameters:
other
- the other LockSet
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containsReturnValue
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
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intersectWith
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
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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
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identicalSubset
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mergeValues
private static int mergeValues(int a, int b) -
findIndex
private int findIndex(int valueNumber) -
addEntry
private void addEntry(int negatedIndex, int valueNumber, int lockCount) -
toString
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getLockedValueNumbers
- Parameters:
frame
-- Returns:
- a set of the locked value numbers
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