Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.services.locks.Lock

Modifier and Type	Field and Description
pack-priv int	count
private final Object	qualifier Qualifier used in the lock request..
private final Lockable	ref Object being locked.
private final CompatibilitySpace	space Compatibility space the object is locked in. MT - immutable - reference only

Access	Constructor and Description
protected	Lock(CompatibilitySpace space, Lockable ref, Object qualifier)

Modifier and Type	Method and Description
public void	addWaiters(Map<K, V> waiters) Implements org.apache.derby.impl.services.locks.Control.addWaiters.
pack-priv final Lock	copy()
public final boolean	equals(Object the reference object with which to compare. other) Overrides java.lang.Object.equals. Indicates whether some other object is "equal to" this one.
public ActiveLock	firstWaiter() Implements org.apache.derby.impl.services.locks.Control.firstWaiter.
public final CompatibilitySpace	getCompatabilitySpace() Implements org.apache.derby.iapi.services.locks.Latch.getCompatabilitySpace. Return the compatibility space this lock is held in. MT - Thread safe
public final int	getCount() Implements org.apache.derby.iapi.services.locks.Latch.getCount. Return the count of locks.
public Lock	getFirstGrant() Implements org.apache.derby.impl.services.locks.Control.getFirstGrant.
public List<E>	getGranted() Implements org.apache.derby.impl.services.locks.Control.getGranted.
public Lock	getLock(CompatibilitySpace compatibilitySpace, Object qualifier) Implements org.apache.derby.impl.services.locks.Control.getLock.
public final Lockable	getLockable() Implements org.apache.derby.iapi.services.locks.Latch.getLockable, org.apache.derby.impl.services.locks.Control.getLockable. Return the object this lock is held on MT - Thread safe
public LockControl	getLockControl() Implements org.apache.derby.impl.services.locks.Control.getLockControl.
public final Object	getQualifier() Implements org.apache.derby.iapi.services.locks.Latch.getQualifier. Return the qualifier lock was obtained with.
public List<E>	getWaiting() Implements org.apache.derby.impl.services.locks.Control.getWaiting.
pack-priv void	grant()
public final int	hashCode() Overrides java.lang.Object.hashCode. Returns a hash code value for this object.
public boolean	isEmpty() Implements org.apache.derby.impl.services.locks.Control.isEmpty.
public boolean	isGrantable(boolean noWaitersBeforeMe, CompatibilitySpace compatibilitySpace, Object requestQualifier) Implements org.apache.derby.impl.services.locks.Control.isGrantable.
public Control	shallowClone() Implements org.apache.derby.impl.services.locks.Control.shallowClone. We can return ourselves here because our identity is immutable and what we returned will not be accessed as a Lock, so the count cannot be changed.
pack-priv int	unlock(int unlockCount)
public boolean	unlock(Latch lockInGroup, int unlockCount) Implements org.apache.derby.impl.services.locks.Control.unlock.

count	back to summary
pack-priv int count

qualifier	back to summary
private final Object qualifier Qualifier used in the lock request.. MT - immutable - reference only

ref	back to summary
private final Lockable ref Object being locked. MT - immutable - reference only

space	back to summary
private final CompatibilitySpace space Compatibility space the object is locked in. MT - immutable - reference only

Lock	back to summary
protected Lock(CompatibilitySpace space, Lockable ref, Object qualifier)

Method Detail

addWaiters	back to summary
public void addWaiters(Map<K, V> waiters) Implements org.apache.derby.impl.services.locks.Control.addWaiters.

copy	back to summary
pack-priv final Lock copy()

equals back to summary

equals	back to summary
public final boolean equals(Object other) Overrides java.lang.Object.equals. Doc from java.lang.Object.equals. Indicates whether some other object is "equal to" this one. The `equals` method implements an equivalence relation on non-null object references: It is reflexive: for any non-null reference value `x`, `x.equals(x)` should return `true`. It is symmetric: for any non-null reference values `x` and `y`, `x.equals(y)` should return `true` if and only if `y.equals(x)` returns `true`. It is transitive: for any non-null reference values `x`, `y`, and `z`, if `x.equals(y)` returns `true` and `y.equals(z)` returns `true`, then `x.equals(z)` should return `true`. It is consistent: for any non-null reference values `x` and `y`, multiple invocations of `x.equals(y)` consistently return `true` or consistently return `false`, provided no information used in `equals` comparisons on the objects is modified. For any non-null reference value `x`, `x.equals(null)` should return `false`. An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes. Parameters other:Object the reference object with which to compare. Returns:boolean `true` if this object is the same as the obj argument; `false` otherwise.

public final boolean equals(Object other)

Overrides java.lang.Object.equals.

Doc from java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

It is reflexive: for any non-null reference value x, x.equals(x) should return true.
It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters

other:Object: the reference object with which to compare.

Returns:boolean

true if this object is the same as the obj argument; false otherwise.

firstWaiter	back to summary
public ActiveLock firstWaiter() Implements org.apache.derby.impl.services.locks.Control.firstWaiter.

getCompatabilitySpace	back to summary
public final CompatibilitySpace getCompatabilitySpace() Implements org.apache.derby.iapi.services.locks.Latch.getCompatabilitySpace. Return the compatibility space this lock is held in. MT - Thread safe Returns:CompatibilitySpace Doc from org.apache.derby.iapi.services.locks.Latch.getCompatabilitySpace. the latch's compatibility space

getCompatabilitySpace

back to summary

public final CompatibilitySpace getCompatabilitySpace()

Implements org.apache.derby.iapi.services.locks.Latch.getCompatabilitySpace.

Return the compatibility space this lock is held in. MT - Thread safe

Returns:CompatibilitySpace

Doc from org.apache.derby.iapi.services.locks.Latch.getCompatabilitySpace.

the latch's compatibility space

getCount	back to summary
public final int getCount() Implements org.apache.derby.iapi.services.locks.Latch.getCount. Return the count of locks. MT - Thread safe

getCount

back to summary

public final int getCount()

Implements org.apache.derby.iapi.services.locks.Latch.getCount.

Return the count of locks. MT - Thread safe

getFirstGrant	back to summary
public Lock getFirstGrant() Implements org.apache.derby.impl.services.locks.Control.getFirstGrant.

getGranted	back to summary
public List<E> getGranted() Implements org.apache.derby.impl.services.locks.Control.getGranted.

getLock	back to summary
public Lock getLock(CompatibilitySpace compatibilitySpace, Object qualifier) Implements org.apache.derby.impl.services.locks.Control.getLock.

getLockable	back to summary
public final Lockable getLockable() Implements org.apache.derby.iapi.services.locks.Latch.getLockable, org.apache.derby.impl.services.locks.Control.getLockable. Return the object this lock is held on MT - Thread safe Returns:Lockable Doc from org.apache.derby.iapi.services.locks.Latch.getLockable. the object the latch is held on

getLockable

back to summary

public final Lockable getLockable()

Implements org.apache.derby.iapi.services.locks.Latch.getLockable, org.apache.derby.impl.services.locks.Control.getLockable.

Return the object this lock is held on MT - Thread safe

Returns:Lockable

Doc from org.apache.derby.iapi.services.locks.Latch.getLockable.

the object the latch is held on

getLockControl	back to summary
public LockControl getLockControl() Implements org.apache.derby.impl.services.locks.Control.getLockControl.

getQualifier	back to summary
public final Object getQualifier() Implements org.apache.derby.iapi.services.locks.Latch.getQualifier. Return the qualifier lock was obtained with. MT - Thread safe Returns:Object Doc from org.apache.derby.iapi.services.locks.Latch.getQualifier. the qualifier used when the latch was obtained

getQualifier

back to summary

public final Object getQualifier()

Implements org.apache.derby.iapi.services.locks.Latch.getQualifier.

Return the qualifier lock was obtained with. MT - Thread safe

Returns:Object

Doc from org.apache.derby.iapi.services.locks.Latch.getQualifier.

the qualifier used when the latch was obtained

getWaiting	back to summary
public List<E> getWaiting() Implements org.apache.derby.impl.services.locks.Control.getWaiting.

grant	back to summary
pack-priv void grant()

hashCode back to summary

hashCode	back to summary
public final int hashCode() Overrides java.lang.Object.hashCode. Doc from java.lang.Object.hashCode. Returns a hash code value for this object. This method is supported for the benefit of hash tables such as those provided by `java.util.HashMap`. The general contract of `hashCode` is: Whenever it is invoked on the same object more than once during an execution of a Java application, the `hashCode` method must consistently return the same integer, provided no information used in `equals` comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. If two objects are equal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce the same integer result. It is not required that if two objects are unequal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables. Returns:int a hash code value for this object

public final int hashCode()

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for this object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns:int: a hash code value for this object

isEmpty	back to summary
public boolean isEmpty() Implements org.apache.derby.impl.services.locks.Control.isEmpty.

isGrantable	back to summary
public boolean isGrantable(boolean noWaitersBeforeMe, CompatibilitySpace compatibilitySpace, Object requestQualifier) Implements org.apache.derby.impl.services.locks.Control.isGrantable.

shallowClone	back to summary
public Control shallowClone() Implements org.apache.derby.impl.services.locks.Control.shallowClone. We can return ourselves here because our identity is immutable and what we returned will not be accessed as a Lock, so the count cannot be changed.

shallowClone

back to summary

public Control shallowClone()

Implements org.apache.derby.impl.services.locks.Control.shallowClone.

We can return ourselves here because our identity is immutable and what we returned will not be accessed as a Lock, so the count cannot be changed.

unlock	back to summary
pack-priv int unlock(int unlockCount)

unlock	back to summary
public boolean unlock(Latch lockInGroup, int unlockCount) Implements org.apache.derby.impl.services.locks.Control.unlock.

pack-priv Class Lock

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