gnu.java.nio

Class SelectorImpl


public class SelectorImpl
extends AbstractSelector

Constructor Summary

SelectorImpl(SelectorProvider provider)
Initializes the slector.

Method Summary

protected void
finalize()
Called on an object by the Virtual Machine at most once, at some point after the Object is determined unreachable but before it is destroyed.
protected void
implCloseSelector()
Closes the channel.
Set
keys()
Returns this selector's key set.
protected SelectionKey
register(SelectableChannel ch, int ops, Object att)
protected SelectionKey
register(AbstractSelectableChannel ch, int ops, Object att)
Registers a channel for the selection process.
int
select()
Selects a set of keys whose corresponding channels are ready for I/O operations.
int
select(long timeout)
Selects a set of keys whose corresponding channels are ready for I/O operations.
int
selectNow()
Selects a set of keys whose corresponding channels are ready for I/O operations.
Set
selectedKeys()
Returns this selector's selected-key set.
Selector
wakeup()
Causes the first selection operation that has not yet returned to return immediately.

Methods inherited from class java.nio.channels.spi.AbstractSelector

begin, cancelledKeys, close, deregister, end, implCloseSelector, isOpen, provider, register

Methods inherited from class java.nio.channels.Selector

close, isOpen, keys, open, provider, select, select, selectNow, selectedKeys, wakeup

Methods inherited from class java.lang.Object

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

Constructor Details

SelectorImpl

public SelectorImpl(SelectorProvider provider)
Initializes the slector.
Parameters:
provider - the provider that created this selector

Method Details

finalize

protected void finalize()
            throws Throwable
Called on an object by the Virtual Machine at most once, at some point after the Object is determined unreachable but before it is destroyed. You would think that this means it eventually is called on every Object, but this is not necessarily the case. If execution terminates abnormally, garbage collection does not always happen. Thus you cannot rely on this method to always work. For finer control over garbage collection, use references from the java.lang.ref package.

Virtual Machines are free to not call this method if they can determine that it does nothing important; for example, if your class extends Object and overrides finalize to do simply super.finalize().

finalize() will be called by a Thread that has no locks on any Objects, and may be called concurrently. There are no guarantees on the order in which multiple objects are finalized. This means that finalize() is usually unsuited for performing actions that must be thread-safe, and that your implementation must be use defensive programming if it is to always work.

If an Exception is thrown from finalize() during garbage collection, it will be patently ignored and the Object will still be destroyed.

It is allowed, although not typical, for user code to call finalize() directly. User invocation does not affect whether automatic invocation will occur. It is also permitted, although not recommended, for a finalize() method to "revive" an object by making it reachable from normal code again.

Unlike constructors, finalize() does not get called for an object's superclass unless the implementation specifically calls super.finalize().

The default implementation does nothing.

Overrides:
finalize in interface Object
Throws:
Throwable - permits a subclass to throw anything in an overridden version; but the default throws nothing

implCloseSelector

protected final void implCloseSelector()
            throws IOException
Closes the channel.
Overrides:
implCloseSelector in interface AbstractSelector
Throws:
IOException - if an error occurs

keys

public final Set keys()
Returns this selector's key set.
Overrides:
keys in interface Selector
Throws:
ClosedSelectorException - If this selector is closed.

register

protected SelectionKey register(SelectableChannel ch,
                                int ops,
                                Object att)

register

protected final SelectionKey register(AbstractSelectableChannel ch,
                                      int ops,
                                      Object att)
Registers a channel for the selection process.
Overrides:
register in interface AbstractSelector
Parameters:
ch - the channel register
ops - the interested operations
att - an attachement to the selection key
Returns:
the registered selection key

select

public final int select()
            throws IOException
Selects a set of keys whose corresponding channels are ready for I/O operations.
Overrides:
select in interface Selector
Throws:
ClosedSelectorException - If this selector is closed.
IOException - If an error occurs

select

public int select(long timeout)
            throws IOException
Selects a set of keys whose corresponding channels are ready for I/O operations.
Overrides:
select in interface Selector
Parameters:
timeout - The timeout to use.
Throws:
ClosedSelectorException - If this selector is closed.
IllegalArgumentException - If the timeout value is negative.
IOException - If an error occurs

selectNow

public final int selectNow()
            throws IOException
Selects a set of keys whose corresponding channels are ready for I/O operations.
Overrides:
selectNow in interface Selector
Throws:
ClosedSelectorException - If this selector is closed.
IOException - If an error occurs

selectedKeys

public final Set selectedKeys()
Returns this selector's selected-key set.
Overrides:
selectedKeys in interface Selector
Throws:
ClosedSelectorException - If this selector is closed.

wakeup

public final Selector wakeup()
Causes the first selection operation that has not yet returned to return immediately.
Overrides:
wakeup in interface Selector

SelectorImpl.java -- Copyright (C) 2002, 2003, 2004, 2006 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.