OpenJDK 27 · sun.nio.ch.SelectorImpl · APIdia, the JavaDoc alternative

Modifier and Type	Field and Description
private final Deque<SelectionKeyImpl>	cancelledKeys Hides java.nio.channels.spi.AbstractSelector.cancelledKeys.
private boolean	inSelect
private final Set<SelectionKey>	keys
private final Set<SelectionKey>	publicKeys
private final Set<SelectionKey>	publicSelectedKeys
private final Set<SelectionKey>	selectedKeys

Access	Constructor and Description
protected	SelectorImpl(SelectorProvider sp)

Method Summary

Modifier and Type	Method and Description
protected final void	begin(boolean blocking) Marks the beginning of a select operation that might block
public void	cancel(SelectionKeyImpl ski) Queue a cancelled key for the next selection operation
protected abstract int	doSelect(Consumer<SelectionKey> the action to perform, can be null action, long timeout in milliseconds to wait, 0 to not wait, -1 to wait indefinitely timeout) Hides java.nio.channels.Selector.doSelect. Selects the keys for channels that are ready for I/O operations.
protected final void	end(boolean blocking) Marks the end of a select operation that may have blocked
private void	ensureOpen()
protected abstract void	implClose() Invoked by implCloseSelector to close the selector.
public final void	implCloseSelector() Implements abstract java.nio.channels.spi.AbstractSelector.implCloseSelector. Closes this selector.
protected abstract void	implDereg(SelectionKeyImpl ski) Removes the key from the selector
protected void	implRegister(SelectionKeyImpl ski) Register the key in the selector.
public final Set<SelectionKey>	keys() Implements abstract java.nio.channels.Selector.keys. Returns this selector's key set.
private int	lockAndDoSelect(Consumer<SelectionKey> action, long timeout)
protected final void	processDeregisterQueue() Invoked by selection operations to process the cancelled keys
protected final int	processReadyEvents(int rOps, SelectionKeyImpl ski, Consumer<SelectionKey> action) Invoked by selection operations to handle ready events.
protected final SelectionKey	register(AbstractSelectableChannel ch, int ops, Object attachment) Implements abstract java.nio.channels.spi.AbstractSelector.register. Registers the given channel with this selector.
public final int	select(long timeout) Implements abstract java.nio.channels.Selector.select. Selects a set of keys whose corresponding channels are ready for I/O operations.
public final int	select() Implements abstract java.nio.channels.Selector.select. Selects a set of keys whose corresponding channels are ready for I/O operations.
public final int	select(Consumer<SelectionKey> action, long timeout) Overrides java.nio.channels.Selector.select. Selects and performs an action on the keys whose corresponding channels are ready for I/O operations.
public final int	select(Consumer<SelectionKey> action) Overrides java.nio.channels.Selector.select. Selects and performs an action on the keys whose corresponding channels are ready for I/O operations.
public final Set<SelectionKey>	selectedKeys() Implements abstract java.nio.channels.Selector.selectedKeys. Returns this selector's selected-key set.
public final int	selectNow() Implements abstract java.nio.channels.Selector.selectNow. Selects a set of keys whose corresponding channels are ready for I/O operations.
public final int	selectNow(Consumer<SelectionKey> action) Overrides java.nio.channels.Selector.selectNow. Selects and performs an action on the keys whose corresponding channels are ready for I/O operations.
protected abstract void	setEventOps(SelectionKeyImpl ski) Invoked by interestOps to ensure the interest ops are updated at the next selection operation.

Inherited from java.nio.channels.spi.AbstractSelector:: begin cancelledKeys close deregister end isOpen provider

cancelledKeys	back to summary
private final Deque<SelectionKeyImpl> cancelledKeys Hides java.nio.channels.spi.AbstractSelector.cancelledKeys.

inSelect	back to summary
private boolean inSelect

keys	back to summary
private final Set<SelectionKey> keys

publicKeys	back to summary
private final Set<SelectionKey> publicKeys

publicSelectedKeys	back to summary
private final Set<SelectionKey> publicSelectedKeys

selectedKeys	back to summary
private final Set<SelectionKey> selectedKeys

SelectorImpl	back to summary
protected SelectorImpl(SelectorProvider sp)

Method Detail

begin	back to summary
protected final void begin(boolean blocking) Marks the beginning of a select operation that might block

cancel	back to summary
public void cancel(SelectionKeyImpl ski) Queue a cancelled key for the next selection operation

doSelect	back to summary
protected abstract int doSelect(Consumer<SelectionKey> action, long timeout) throws IOException Hides java.nio.channels.Selector.doSelect. Selects the keys for channels that are ready for I/O operations. Parameters action:Consumer<SelectionKey> the action to perform, can be null timeout:long timeout in milliseconds to wait, 0 to not wait, -1 to wait indefinitely

doSelect

back to summary

protected abstract int doSelect(Consumer<SelectionKey> action, long timeout) throws IOException

Hides java.nio.channels.Selector.doSelect.

Selects the keys for channels that are ready for I/O operations.

Parameters

action:Consumer<SelectionKey>: the action to perform, can be null
timeout:long: timeout in milliseconds to wait, 0 to not wait, -1 to wait indefinitely

end	back to summary
protected final void end(boolean blocking) Marks the end of a select operation that may have blocked

ensureOpen	back to summary
private void ensureOpen()

implClose	back to summary
protected abstract void implClose() throws IOException Invoked by implCloseSelector to close the selector.

implCloseSelector back to summary

implCloseSelector	back to summary
public final void implCloseSelector() throws IOException Implements abstract java.nio.channels.spi.AbstractSelector.implCloseSelector. Doc from java.nio.channels.spi.AbstractSelector.implCloseSelector. Closes this selector. This method is invoked by the `close` method in order to perform the actual work of closing the selector. This method is only invoked if the selector 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 a selection operation upon this selector to return immediately as if by invoking the `wakeup` method. Annotations @Override Exceptions IOException: If an I/O error occurs while closing the selector

public final void implCloseSelector() throws IOException

Implements abstract java.nio.channels.spi.AbstractSelector.implCloseSelector.

Doc from java.nio.channels.spi.AbstractSelector.implCloseSelector.

Closes this selector.

This method is invoked by the close method in order to perform the actual work of closing the selector. This method is only invoked if the selector 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 a selection operation upon this selector to return immediately as if by invoking the wakeup method.

Annotations

@Override

Exceptions

IOException:: If an I/O error occurs while closing the selector

implDereg	back to summary
protected abstract void implDereg(SelectionKeyImpl ski) throws IOException Removes the key from the selector

implRegister	back to summary
protected void implRegister(SelectionKeyImpl ski) Register the key in the selector. The default implementation checks if the selector is open. It should be overridden by selector implementations as needed.

keys back to summary

keys	back to summary
public final Set<SelectionKey> keys() Implements abstract java.nio.channels.Selector.keys. Doc from java.nio.channels.Selector.keys. Returns this selector's key set. The key set is not directly modifiable. A key is removed only after it has been cancelled and its channel has been deregistered. Any attempt to modify the key set will cause an `UnsupportedOperationException` to be thrown. The set is safe for use by multiple concurrent threads. Annotations @Override

public final Set<SelectionKey> keys()

Implements abstract java.nio.channels.Selector.keys.

Doc from java.nio.channels.Selector.keys.

Returns this selector's key set.

The key set is not directly modifiable. A key is removed only after it has been cancelled and its channel has been deregistered. Any attempt to modify the key set will cause an UnsupportedOperationException to be thrown.

The set is safe for use by multiple concurrent threads.

Annotations

@Override

lockAndDoSelect	back to summary
private int lockAndDoSelect(Consumer<SelectionKey> action, long timeout) throws IOException

processDeregisterQueue	back to summary
protected final void processDeregisterQueue() throws IOException Invoked by selection operations to process the cancelled keys

processReadyEvents	back to summary
protected final int processReadyEvents(int rOps, SelectionKeyImpl ski, Consumer<SelectionKey> action) Invoked by selection operations to handle ready events. If an action is specified then it is invoked to handle the key, otherwise the key is added to the selected-key set (or updated when it is already in the set).

register	back to summary
protected final SelectionKey register(AbstractSelectableChannel ch, int ops, Object attachment) Implements abstract java.nio.channels.spi.AbstractSelector.register. Doc from java.nio.channels.spi.AbstractSelector.register. Registers the given channel with this selector. This method is invoked by a channel's `register` method in order to perform the actual work of registering the channel with this selector. Annotations @Override

protected final SelectionKey register(AbstractSelectableChannel ch, int ops, Object attachment)

Implements abstract java.nio.channels.spi.AbstractSelector.register.

Doc from java.nio.channels.spi.AbstractSelector.register.

Registers the given channel with this selector.

This method is invoked by a channel's register method in order to perform the actual work of registering the channel with this selector.

Annotations

@Override

select back to summary

select	back to summary
public final int select(long timeout) throws IOException Implements abstract java.nio.channels.Selector.select. Doc from java.nio.channels.Selector.select. Selects a set of keys whose corresponding channels are ready for I/O operations. This method performs a blocking selection operation. It returns only after at least one channel is selected, this selector's `wakeup` method is invoked, the current thread is interrupted, or the given timeout period expires, whichever comes first. This method does not offer real-time guarantees: It schedules the timeout as if by invoking the `Object#wait(long)` method. Annotations @Override Exceptions IOException: If an I/O error occurs

public final int select(long timeout) throws IOException

Implements abstract java.nio.channels.Selector.select.

Doc from java.nio.channels.Selector.select.

Selects a set of keys whose corresponding channels are ready for I/O operations.

This method performs a blocking selection operation. It returns only after at least one channel is selected, this selector's wakeup method is invoked, the current thread is interrupted, or the given timeout period expires, whichever comes first.

This method does not offer real-time guarantees: It schedules the timeout as if by invoking the Object#wait(long) method.

Annotations

@Override

Exceptions

IOException:: If an I/O error occurs

select back to summary

select	back to summary
public final int select() throws IOException Implements abstract java.nio.channels.Selector.select. Doc from java.nio.channels.Selector.select. Selects a set of keys whose corresponding channels are ready for I/O operations. This method performs a blocking selection operation. It returns only after at least one channel is selected, this selector's `wakeup` method is invoked, or the current thread is interrupted, whichever comes first. Annotations @Override Exceptions IOException: If an I/O error occurs

public final int select() throws IOException

Implements abstract java.nio.channels.Selector.select.

Doc from java.nio.channels.Selector.select.

Selects a set of keys whose corresponding channels are ready for I/O operations.

This method performs a blocking selection operation. It returns only after at least one channel is selected, this selector's wakeup method is invoked, or the current thread is interrupted, whichever comes first.

Annotations

@Override

Exceptions

IOException:: If an I/O error occurs

select back to summary

select	back to summary
public final int select(Consumer<SelectionKey> action, long timeout) throws IOException Overrides java.nio.channels.Selector.select. Doc from java.nio.channels.Selector.select. Selects and performs an action on the keys whose corresponding channels are ready for I/O operations. This method performs a blocking selection operation. It wakes up from querying the operating system only when at least one channel is selected, this selector's `wakeup` method is invoked, the current thread is interrupted, or the given timeout period expires, whichever comes first. The specified action's `accept` method is invoked with the key for each channel that is ready to perform an operation identified by its key's interest set. The `accept` method may be invoked more than once for the same key but with the ready-operation set containing a subset of the operations for which the channel is ready (as described above). The `accept` method is invoked while synchronized on the selector and its selected-key set. Great care must be taken to avoid deadlocking with other threads that also synchronize on these objects. Selection operations are not reentrant in general and consequently the action should take great care not to attempt a selection operation on the same selector. The behavior when attempting a reentrant selection operation is implementation specific and therefore not specified. If the action closes the selector then `ClosedSelectorException` is thrown when the action completes. The action is not prohibited from closing channels registered with the selector, nor prohibited from cancelling keys or changing a key's interest set. If a channel is selected but its key is cancelled or its interest set changed before the action is performed on the key then it is implementation specific as to whether the action is invoked (it may be invoked with an `invalid` key). Exceptions thrown by the action are relayed to the caller. This method does not offer real-time guarantees: It schedules the timeout as if by invoking the `Object#wait(long)` method. Annotations @Override Exceptions IOException: If an I/O error occurs

public final int select(Consumer<SelectionKey> action, long timeout) throws IOException

Overrides java.nio.channels.Selector.select.

Doc from java.nio.channels.Selector.select.

Selects and performs an action on the keys whose corresponding channels are ready for I/O operations.

This method performs a blocking selection operation. It wakes up from querying the operating system only when at least one channel is selected, this selector's wakeup method is invoked, the current thread is interrupted, or the given timeout period expires, whichever comes first.

The specified action's accept method is invoked with the key for each channel that is ready to perform an operation identified by its key's interest set. The accept method may be invoked more than once for the same key but with the ready-operation set containing a subset of the operations for which the channel is ready (as described above). The accept method is invoked while synchronized on the selector and its selected-key set. Great care must be taken to avoid deadlocking with other threads that also synchronize on these objects. Selection operations are not reentrant in general and consequently the action should take great care not to attempt a selection operation on the same selector. The behavior when attempting a reentrant selection operation is implementation specific and therefore not specified. If the action closes the selector then ClosedSelectorException is thrown when the action completes. The action is not prohibited from closing channels registered with the selector, nor prohibited from cancelling keys or changing a key's interest set. If a channel is selected but its key is cancelled or its interest set changed before the action is performed on the key then it is implementation specific as to whether the action is invoked (it may be invoked with an invalid key). Exceptions thrown by the action are relayed to the caller.

This method does not offer real-time guarantees: It schedules the timeout as if by invoking the Object#wait(long) method.

Annotations

@Override

Exceptions

IOException:: If an I/O error occurs

select back to summary

select	back to summary
public final int select(Consumer<SelectionKey> action) throws IOException Overrides java.nio.channels.Selector.select. Doc from java.nio.channels.Selector.select. Selects and performs an action on the keys whose corresponding channels are ready for I/O operations. This method performs a blocking selection operation. It wakes up from querying the operating system only when at least one channel is selected, this selector's `wakeup` method is invoked, or the current thread is interrupted, whichever comes first. This method is equivalent to invoking the 2-arg `select` method with a timeout of `0` to block indefinitely. Annotations @Override Exceptions IOException: If an I/O error occurs

public final int select(Consumer<SelectionKey> action) throws IOException

Overrides java.nio.channels.Selector.select.

Doc from java.nio.channels.Selector.select.

Selects and performs an action on the keys whose corresponding channels are ready for I/O operations.

This method performs a blocking selection operation. It wakes up from querying the operating system only when at least one channel is selected, this selector's wakeup method is invoked, or the current thread is interrupted, whichever comes first.

This method is equivalent to invoking the 2-arg select method with a timeout of 0 to block indefinitely.

Annotations

@Override

Exceptions

IOException:: If an I/O error occurs

selectedKeys back to summary

selectedKeys	back to summary
public final Set<SelectionKey> selectedKeys() Implements abstract java.nio.channels.Selector.selectedKeys. Doc from java.nio.channels.Selector.selectedKeys. Returns this selector's selected-key set. Keys may be removed from, but not directly added to, the selected-key set. Any attempt to add an object to the key set will cause an `UnsupportedOperationException` to be thrown. The selected-key set is not thread-safe. Annotations @Override

public final Set<SelectionKey> selectedKeys()

Implements abstract java.nio.channels.Selector.selectedKeys.

Doc from java.nio.channels.Selector.selectedKeys.

Returns this selector's selected-key set.

Keys may be removed from, but not directly added to, the selected-key set. Any attempt to add an object to the key set will cause an UnsupportedOperationException to be thrown.

The selected-key set is not thread-safe.

Annotations

@Override

selectNow back to summary

selectNow	back to summary
public final int selectNow() throws IOException Implements abstract java.nio.channels.Selector.selectNow. Doc from java.nio.channels.Selector.selectNow. Selects a set of keys whose corresponding channels are ready for I/O operations. This method performs a non-blocking selection operation. If no channels have become selectable since the previous selection operation then this method immediately returns zero. Invoking this method clears the effect of any previous invocations of the `wakeup` method. Annotations @Override Exceptions IOException: If an I/O error occurs

public final int selectNow() throws IOException

Implements abstract java.nio.channels.Selector.selectNow.

Doc from java.nio.channels.Selector.selectNow.

Selects a set of keys whose corresponding channels are ready for I/O operations.

This method performs a non-blocking selection operation. If no channels have become selectable since the previous selection operation then this method immediately returns zero.

Invoking this method clears the effect of any previous invocations of the wakeup method.

Annotations

@Override

Exceptions

IOException:: If an I/O error occurs

selectNow back to summary

selectNow	back to summary
public final int selectNow(Consumer<SelectionKey> action) throws IOException Overrides java.nio.channels.Selector.selectNow. Doc from java.nio.channels.Selector.selectNow. Selects and performs an action on the keys whose corresponding channels are ready for I/O operations. This method performs a non-blocking selection operation. Invoking this method clears the effect of any previous invocations of the `wakeup` method. Annotations @Override Exceptions IOException: If an I/O error occurs

public final int selectNow(Consumer<SelectionKey> action) throws IOException

Overrides java.nio.channels.Selector.selectNow.

Doc from java.nio.channels.Selector.selectNow.

Selects and performs an action on the keys whose corresponding channels are ready for I/O operations.

This method performs a non-blocking selection operation.

Invoking this method clears the effect of any previous invocations of the wakeup method.

Annotations

@Override

Exceptions

IOException:: If an I/O error occurs

setEventOps	back to summary
protected abstract void setEventOps(SelectionKeyImpl ski) Invoked by interestOps to ensure the interest ops are updated at the next selection operation.

public abstract Class SelectorImpl

Field Summary

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Field Detail

Constructor Detail

Method Detail