Class NioIoHandler

java.lang.Object

io.netty.channel.nio.NioIoHandler

All Implemented Interfaces:

IoHandler

public final class NioIoHandler
extends Object
implements IoHandler

IoHandler implementation which register the IoHandle's to a Selector.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) final class	NioIoHandler.DefaultNioRegistration
private static final class	NioIoHandler.SelectorTuple

Field Summary

Fields

Modifier and Type	Field	Description
private int	cancelledKeys
private static final int	CLEANUP_INTERVAL
private static final boolean	DISABLE_KEY_SET_OPTIMIZATION
private final ThreadAwareExecutor	executor
private static final InternalLogger	logger
private static final int	MIN_PREMATURE_SELECTOR_RETURNS
private boolean	needsToSelectAgain
private final SelectorProvider	provider
private SelectedSelectionKeySet	selectedKeys
private final IntSupplier	selectNowSupplier
private Selector	selector	The NIO Selector.
private static final int	SELECTOR_AUTO_REBUILD_THRESHOLD
private final SelectStrategy	selectStrategy
private Selector	unwrappedSelector
private final AtomicBoolean	wakenUp	Boolean that controls determines if a blocked Selector.select should break out of its selection process.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	NioIoHandler(ThreadAwareExecutor executor, SelectorProvider selectorProvider, SelectStrategy strategy)

Method Summary

Modifier and Type	Method	Description
private static NioIoOps	cast(IoOps ops)
void	destroy()	Destroy the IoHandler and free all its resources.
private static void	handleLoopException(Throwable t)
boolean	isCompatible(Class<? extends IoHandle> handleType)	Returns true if the given type is compatible with this IoHandler and so can be registered, false otherwise.
private static long	millisBeforeDeadline(long selectDeadLineNanos, long currentTimeNanos)
static IoHandlerFactory	newFactory()	Returns a new IoHandlerFactory that creates NioIoHandler instances
static IoHandlerFactory	newFactory(SelectorProvider selectorProvider)	Returns a new IoHandlerFactory that creates NioIoHandler instances.
static IoHandlerFactory	newFactory(SelectorProvider selectorProvider, SelectStrategyFactory selectStrategyFactory)	Returns a new IoHandlerFactory that creates NioIoHandler instances.
private static NioIoHandle	nioHandle(IoHandle handle)
(package private) int	numRegistered()
private NioIoHandler.SelectorTuple	openSelector()
void	prepareToDestroy()	Prepare to destroy this IoHandler.
private void	processSelectedKey(SelectionKey k)
private int	processSelectedKeys()
private int	processSelectedKeysOptimized()
private int	processSelectedKeysPlain(Set<SelectionKey> selectedKeys)
(package private) void	rebuildSelector0()
IoRegistration	register(IoHandle handle)	Register a IoHandle for IO.
(package private) Set<SelectionKey>	registeredSet()
int	run(IoHandlerContext context)	Run the IO handled by this IoHandler.
private void	select(IoHandlerContext runner, boolean oldWakenUp)
private void	selectAgain()
(package private) int	selectNow()
(package private) Selector	selector()
SelectorProvider	selectorProvider()	Returns the SelectorProvider used by this NioEventLoop to obtain the Selector.
private Selector	selectRebuildSelector(int selectCnt)
(package private) Selector	unwrappedSelector()
void	wakeup()	Wakeup the IoHandler, which means if any operation blocks it should be unblocked and return as soon as possible.

Methods inherited from class Object

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

Methods inherited from interface IoHandler

initialize

Field Details

logger

private static final InternalLogger logger

CLEANUP_INTERVAL

private static final int CLEANUP_INTERVAL

See Also:

• Constant Field Values

DISABLE_KEY_SET_OPTIMIZATION

private static final boolean DISABLE_KEY_SET_OPTIMIZATION

MIN_PREMATURE_SELECTOR_RETURNS

private static final int MIN_PREMATURE_SELECTOR_RETURNS

See Also:

• Constant Field Values

SELECTOR_AUTO_REBUILD_THRESHOLD

private static final int SELECTOR_AUTO_REBUILD_THRESHOLD

selectNowSupplier

private final IntSupplier selectNowSupplier

selector

private Selector selector

The NIO Selector.

unwrappedSelector

private Selector unwrappedSelector

selectedKeys

private SelectedSelectionKeySet selectedKeys

provider

private final SelectorProvider provider

wakenUp

private final AtomicBoolean wakenUp

Boolean that controls determines if a blocked Selector.select should break out of its selection process. In our case we use a timeout for the select method and the select method will block for that time unless waken up.

selectStrategy

private final SelectStrategy selectStrategy

executor

private final ThreadAwareExecutor executor

cancelledKeys

private int cancelledKeys

needsToSelectAgain

private boolean needsToSelectAgain

Constructor Details

NioIoHandler

private NioIoHandler(ThreadAwareExecutor executor,
 SelectorProvider selectorProvider,
 SelectStrategy strategy)

Method Details

openSelector

private NioIoHandler.SelectorTuple openSelector()

selectorProvider

public SelectorProvider selectorProvider()

Returns the SelectorProvider used by this NioEventLoop to obtain the Selector.

selector

Selector selector()

numRegistered

int numRegistered()

registeredSet

Set<SelectionKey> registeredSet()

rebuildSelector0

void rebuildSelector0()

nioHandle

private static NioIoHandle nioHandle(IoHandle handle)

cast

private static NioIoOps cast(IoOps ops)

register

public IoRegistration register(IoHandle handle)
                        throws Exception

Description copied from interface: IoHandler

Register a IoHandle for IO.

Specified by:

register in interface IoHandler

Parameters:

handle - the IoHandle to register.

Throws:

Exception - thrown if an error happens during registration.

run

public int run(IoHandlerContext context)

Description copied from interface: IoHandler

Run the IO handled by this IoHandler. The IoHandlerContext should be used to ensure we not execute too long and so block the processing of other task that are scheduled on the ThreadAwareExecutor. This is done by taking IoHandlerContext.delayNanos(long) or IoHandlerContext.deadlineNanos() into account.

Specified by:

run in interface IoHandler

Parameters:

context - the IoHandlerContext.

Returns:

the number of IoHandle for which I/O was handled. Internal events such as wakeups and timer expirations must not be included in this count.

handleLoopException

private static void handleLoopException(Throwable t)

processSelectedKeys

private int processSelectedKeys()

destroy

public void destroy()

Description copied from interface: IoHandler

Destroy the IoHandler and free all its resources. Once destroyed using the IoHandler will cause undefined behaviour.

Specified by:

destroy in interface IoHandler

processSelectedKeysPlain

private int processSelectedKeysPlain(Set<SelectionKey> selectedKeys)

processSelectedKeysOptimized

private int processSelectedKeysOptimized()

processSelectedKey

private void processSelectedKey(SelectionKey k)

prepareToDestroy

public void prepareToDestroy()

Description copied from interface: IoHandler

Prepare to destroy this IoHandler. This method will be called before IoHandler.destroy() and may be called multiple times.

Specified by:

prepareToDestroy in interface IoHandler

wakeup

public void wakeup()

Description copied from interface: IoHandler

Wakeup the IoHandler, which means if any operation blocks it should be unblocked and return as soon as possible.

Specified by:

wakeup in interface IoHandler

isCompatible

public boolean isCompatible(Class<? extends IoHandle> handleType)

Description copied from interface: IoHandler

Returns true if the given type is compatible with this IoHandler and so can be registered, false otherwise.

Specified by:

isCompatible in interface IoHandler

Parameters:

handleType - the type of the IoHandle.

Returns:

if compatible of not.

unwrappedSelector

Selector unwrappedSelector()

select

private void select(IoHandlerContext runner,
 boolean oldWakenUp)
             throws IOException

Throws:

IOException

millisBeforeDeadline

private static long millisBeforeDeadline(long selectDeadLineNanos,
 long currentTimeNanos)

selectNow

int selectNow()
       throws IOException

Throws:

IOException

selectRebuildSelector

private Selector selectRebuildSelector(int selectCnt)
                                throws IOException

Throws:

IOException

selectAgain

private void selectAgain()

newFactory

public static IoHandlerFactory newFactory()

Returns a new IoHandlerFactory that creates NioIoHandler instances

Returns:

factory the IoHandlerFactory.

newFactory

public static IoHandlerFactory newFactory(SelectorProvider selectorProvider)

Returns a new IoHandlerFactory that creates NioIoHandler instances.

Parameters:

selectorProvider - the SelectorProvider to use.

Returns:

factory the IoHandlerFactory.

newFactory

public static IoHandlerFactory newFactory(SelectorProvider selectorProvider,
 SelectStrategyFactory selectStrategyFactory)

Returns a new IoHandlerFactory that creates NioIoHandler instances.

Parameters:

selectorProvider - the SelectorProvider to use.

selectStrategyFactory - the SelectStrategyFactory to use.

Returns:

factory the IoHandlerFactory.