Added in API level 1

AbstractSelectableChannel

abstract class AbstractSelectableChannel : SelectableChannel

kotlin.Any
↳	java.nio.channels.spi.AbstractInterruptibleChannel
	↳	java.nio.channels.SelectableChannel
		↳	java.nio.channels.spi.AbstractSelectableChannel

Known Direct Subclasses

DatagramChannel, Pipe.SinkChannel, Pipe.SourceChannel, ServerSocketChannel, SocketChannel

DatagramChannel	A selectable channel for datagram-oriented sockets.
Pipe.SinkChannel	A channel representing the writable end of a `Pipe`.
Pipe.SourceChannel	A channel representing the readable end of a `Pipe`.
ServerSocketChannel	A selectable channel for stream-oriented listening sockets.
SocketChannel	A selectable channel for stream-oriented connecting sockets.

Base implementation class for selectable channels.

This class defines methods that handle the mechanics of channel registration, deregistration, and closing. It maintains the current blocking mode of this channel as well as its current set of selection keys. It performs all of the synchronization required to implement the java.nio.channels.SelectableChannel specification. Implementations of the abstract protected methods defined in this class need not synchronize against other threads that might be engaged in the same operations.

Summary

Protected constructors
`AbstractSelectableChannel(provider: SelectorProvider!)` Initializes a new instance of this class.

Public methods
Any!	`blockingLock()` Retrieves the object upon which the `configureBlocking` and #register methods synchronize.
SelectableChannel!	`configureBlocking(block: Boolean)` Adjusts this channel's blocking mode.
Boolean	`isBlocking()` Tells whether or not every I/O operation on this channel will block until it completes.
Boolean	`isRegistered()` Tells whether or not this channel is currently registered with any selectors.
SelectionKey!	`keyFor(sel: Selector!)` Retrieves the key representing the channel's registration with the given selector.
SelectorProvider!	`provider()` Returns the provider that created this channel.
SelectionKey!	`register(sel: Selector!, ops: Int, att: Any!)` Registers this channel with the given selector, returning a selection key.

Protected methods
Unit	`implCloseChannel()` Closes this channel.
abstract Unit	`implCloseSelectableChannel()` Closes this selectable channel.
abstract Unit	`implConfigureBlocking(block: Boolean)` Adjusts this channel's blocking mode.

Inherited functions

From class AbstractInterruptibleChannel

`Unit`	`begin()` Marks the beginning of an I/O operation that might block indefinitely. This method should be invoked in tandem with the `end` method, using a `try` ... `finally` block as shown above, in order to implement asynchronous closing and interruption for this channel.
`Unit`	`close()` Closes this channel. If the channel has already been closed then this method returns immediately. Otherwise it marks the channel as closed and then invokes the `implCloseChannel` method in order to complete the close operation.
`Unit`	`end(completed: Boolean)` Marks the end of an I/O operation that might block indefinitely. This method should be invoked in tandem with the `begin` method, using a `try` ... `finally` block as shown above, in order to implement asynchronous closing and interruption for this channel.
`Unit`	`implCloseChannel()` Closes this channel. This method is invoked by the #close method in order to perform the actual work of closing the channel. This method is only invoked if the channel has not yet been closed, and it is never invoked more than once. An implementation of this method must arrange for any other thread that is blocked in an I/O operation upon this channel to return immediately, either by throwing an exception or by returning normally.
`Boolean`	`isOpen()` Tells whether or not this channel is open.

From class SelectableChannel

SelectionKey!

register(sel: Selector!, ops: Int)

Registers this channel with the given selector, returning a selection key.

An invocation of this convenience method of the form

sc.register(sel, ops) behaves in exactly the same way as the invocation sc.register(sel, ops, null)

Int

validOps()

Returns an operation set identifying this channel's supported operations. The bits that are set in this integer value denote exactly the operations that are valid for this channel. This method always returns the same value for a given concrete channel class.

Protected constructors

AbstractSelectableChannel

Added in API level 1

protected AbstractSelectableChannel(provider: SelectorProvider!)

Initializes a new instance of this class.

Parameters
`provider`	SelectorProvider!: The provider that created this channel

Public methods

blockingLock

Added in API level 1

fun blockingLock(): Any!

Retrieves the object upon which the configureBlocking and #register methods synchronize. This is often useful in the implementation of adaptors that require a specific blocking mode to be maintained for a short period of time.

Return
`Any!`	The blocking-mode lock object

configureBlocking

Added in API level 1

fun configureBlocking(block: Boolean): SelectableChannel!

Adjusts this channel's blocking mode.

If the given blocking mode is different from the current blocking mode then this method invokes the implConfigureBlocking method, while holding the appropriate locks, in order to change the mode.

Parameters
`block`	Boolean: If `true` then this channel will be placed in blocking mode; if `false` then it will be placed non-blocking mode

Return
`SelectableChannel!`	This selectable channel

Exceptions
`java.io.IOException`	If an I/O error occurs
`java.nio.channels.ClosedChannelException`	If this channel is closed
`java.nio.channels.IllegalBlockingModeException`	If `block` is `true` and this channel is registered with one or more selectors

isBlocking

Added in API level 1

fun isBlocking(): Boolean

Tells whether or not every I/O operation on this channel will block until it completes. A newly-created channel is always in blocking mode.

If this channel is closed then the value returned by this method is not specified.

Return
`Boolean`	`true` if, and only if, this channel is in blocking mode

isRegistered

Added in API level 1

fun isRegistered(): Boolean

Tells whether or not this channel is currently registered with any selectors. A newly-created channel is not registered.

Due to the inherent delay between key cancellation and channel deregistration, a channel may remain registered for some time after all of its keys have been cancelled. A channel may also remain registered for some time after it is closed.

Return
`Boolean`	`true` if, and only if, this channel is registered

keyFor

Added in API level 1

fun keyFor(sel: Selector!): SelectionKey!

Retrieves the key representing the channel's registration with the given selector.

Parameters
`sel`	Selector!: The selector

Return
`SelectionKey!`	The key returned when this channel was last registered with the given selector, or `null` if this channel is not currently registered with that selector

provider

Added in API level 1

fun provider(): SelectorProvider!

Returns the provider that created this channel.

Return
`SelectorProvider!`	The provider that created this channel

register

Added in API level 1

fun register(
    sel: Selector!, 
    ops: Int, 
    att: Any!
): SelectionKey!

Registers this channel with the given selector, returning a selection key.

This method first verifies that this channel is open and that the given initial interest set is valid.

If this channel is already registered with the given selector then the selection key representing that registration is returned after setting its interest set to the given value.

Otherwise this channel has not yet been registered with the given selector, so the register method of the selector is invoked while holding the appropriate locks. The resulting key is added to this channel's key set before being returned.

Parameters
`sel`	Selector!: The selector with which this channel is to be registered
`ops`	Int: The interest set for the resulting key
`att`	Any!: The attachment for the resulting key; may be `null`

Return
`SelectionKey!`	A key representing the registration of this channel with the given selector

Exceptions
`java.lang.IllegalArgumentException`	If a bit in the `ops` set does not correspond to an operation that is supported by this channel, that is, if `set & ~validOps() != 0`
`java.nio.channels.CancelledKeyException`	If this channel is currently registered with the given selector but the corresponding key has already been cancelled
`java.nio.channels.ClosedChannelException`	If this channel is closed
`java.nio.channels.ClosedSelectorException`	If the selector is closed
`java.nio.channels.IllegalBlockingModeException`	If this channel is in blocking mode
`java.nio.channels.IllegalSelectorException`	If this channel was not created by the same provider as the given selector

Protected methods

implCloseChannel

Added in API level 1

protected fun implCloseChannel(): Unit

Closes this channel.

This method, which is specified in the AbstractInterruptibleChannel class and is invoked by the java.nio.channels.Channel#close method, in turn invokes the implCloseSelectableChannel method in order to perform the actual work of closing this channel. It then cancels all of this channel's keys.

Exceptions
`java.io.IOException`	If an I/O error occurs while closing the channel

implCloseSelectableChannel

Added in API level 1

protected abstract fun implCloseSelectableChannel(): Unit

Closes this selectable channel.

This method is invoked by the java.nio.channels.Channel#close method in order to perform the actual work of closing the channel. This method is only invoked if the channel has not yet been closed, and it is never invoked more than once.

An implementation of this method must arrange for any other thread that is blocked in an I/O operation upon this channel to return immediately, either by throwing an exception or by returning normally.

Exceptions
`java.io.IOException`	If an I/O error occurs

implConfigureBlocking

Added in API level 1

protected abstract fun implConfigureBlocking(block: Boolean): Unit

Adjusts this channel's blocking mode.

This method is invoked by the configureBlocking method in order to perform the actual work of changing the blocking mode. This method is only invoked if the new mode is different from the current mode.

Parameters
`block`	Boolean: If `true` then this channel will be placed in blocking mode; if `false` then it will be placed non-blocking mode

Exceptions
`java.io.IOException`	If an I/O error occurs