org.apache.flink.util

Class AbstractCloseableRegistry<C extends Closeable,T>

java.lang.Object

org.apache.flink.util.AbstractCloseableRegistry<C,T>

Type Parameters:

C - Type of the closeable this registers

T - Type for potential meta data associated with the registering closeables

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

CloseableRegistry, SafetyNetCloseableRegistry

@Internal
public abstract class AbstractCloseableRegistry<C extends Closeable,T>
extends Object
implements Closeable

This is the abstract base class for registries that allow to register instances of Closeable, which are all closed if this registry is closed.

Registering to an already closed registry will throw an exception and close the provided Closeable

All methods in this class are thread-safe.

Constructor Summary

Constructors

Constructor and Description
AbstractCloseableRegistry(Map<Closeable,T> closeableToRef)

Method Summary

Modifier and Type	Method and Description
protected void	addCloseableInternal(Closeable closeable, T metaData) Adds a mapping to the registry map, respecting locking.
void	close()
protected abstract void	doRegister(C closeable, Map<Closeable,T> closeableMap) Does the actual registration of the closeable with the registry map.
protected abstract boolean	doUnRegister(C closeable, Map<Closeable,T> closeableMap) Does the actual un-registration of the closeable from the registry map.
int	getNumberOfRegisteredCloseables()
protected Object	getSynchronizationLock() Returns the lock on which manipulations to members closeableToRef and closeable must be synchronized.
boolean	isCloseableRegistered(Closeable c)
boolean	isClosed()
void	registerCloseable(C closeable) Registers a Closeable with the registry.
protected void	removeCloseableInternal(Closeable closeable) Removes a mapping from the registry map, respecting locking.
boolean	unregisterCloseable(C closeable) Removes a Closeable from the registry.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractCloseableRegistry

public AbstractCloseableRegistry(@Nonnull
                                 Map<Closeable,T> closeableToRef)

Method Detail

registerCloseable

public final void registerCloseable(C closeable)
                             throws IOException

Registers a Closeable with the registry. In case the registry is already closed, this method throws an IllegalStateException and closes the passed Closeable.

Parameters:

closeable - Closeable tor register

Throws:

IOException - exception when the registry was closed before

unregisterCloseable

public final boolean unregisterCloseable(C closeable)

Removes a Closeable from the registry.

Parameters:

closeable - instance to remove from the registry.

Returns:

true if the closeable was previously registered and became unregistered through this call.

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

isClosed

public boolean isClosed()

doRegister

protected abstract void doRegister(@Nonnull
                                   C closeable,
                                   @Nonnull
                                   Map<Closeable,T> closeableMap)

Does the actual registration of the closeable with the registry map. This should not do any long running or potentially blocking operations as is is executed under the registry's lock.

doUnRegister

protected abstract boolean doUnRegister(@Nonnull
                                        C closeable,
                                        @Nonnull
                                        Map<Closeable,T> closeableMap)

Does the actual un-registration of the closeable from the registry map. This should not do any long running or potentially blocking operations as is is executed under the registry's lock.

getSynchronizationLock

protected final Object getSynchronizationLock()

Returns the lock on which manipulations to members closeableToRef and closeable must be synchronized.

addCloseableInternal

protected final void addCloseableInternal(Closeable closeable,
                                          T metaData)

Adds a mapping to the registry map, respecting locking.

removeCloseableInternal

protected final void removeCloseableInternal(Closeable closeable)

Removes a mapping from the registry map, respecting locking.

getNumberOfRegisteredCloseables

@VisibleForTesting
public final int getNumberOfRegisteredCloseables()

isCloseableRegistered

@VisibleForTesting
public final boolean isCloseableRegistered(Closeable c)