Modifier and Type	Class and Description
protected static class	SynchronousChannel.Queue Simple FIFO queue class to hold waiting puts/takes.

Modifier and Type	Field and Description
protected static final Object	CANCELLED Special marker used in queue nodes to indicate that the thread waiting for a change in the node has timed out or been interrupted.
protected final SynchronousChannel.Queue	waitingPuts
protected final SynchronousChannel.Queue	waitingTakes

Access	Constructor and Description
public	SynchronousChannel()

Method Summary

Modifier and Type	Method and Description
public int	Returns: zero -- Synchronous channels have no internal capacity. capacity() Implements EDU.oswego.cs.dl.util.concurrent.BoundedChannel.capacity. Return the maximum number of elements that can be held.
public boolean	offer(Object the element to be inserted. Should be non-null. x, long the number of milliseconds to wait. If less than or equal to zero, the method does not perform any timed waits, but might still require access to a synchronization lock, which can impose unbounded delay if there is a lot of contention for the channel. msecs) Implements EDU.oswego.cs.dl.util.concurrent.Channel.offer. Place item in channel only if it can be accepted within msecs milliseconds.
public Object	Returns: null -- Synchronous channels do not hold contents unless actively taken peek() Implements EDU.oswego.cs.dl.util.concurrent.Channel.peek. Return, but do not remove object at head of Channel, or null if it is empty.
public Object	poll(long the number of milliseconds to wait. If less than or equal to zero, the operation does not perform any timed waits, but might still require access to a synchronization lock, which can impose unbounded delay if there is a lot of contention for the channel. msecs) Implements EDU.oswego.cs.dl.util.concurrent.Channel.poll. Return and remove an item from channel only if one is available within msecs milliseconds.
public void	put(Object the element to be inserted. Should be non-null. x) Implements EDU.oswego.cs.dl.util.concurrent.Channel.put. Place item in the channel, possibly waiting indefinitely until it can be accepted.
public Object	take() Implements EDU.oswego.cs.dl.util.concurrent.Channel.take. Return and remove an item from channel, possibly waiting indefinitely until such an item exists.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

CANCELLED	back to summary
protected static final Object CANCELLED Special marker used in queue nodes to indicate that the thread waiting for a change in the node has timed out or been interrupted.

waitingPuts	back to summary
protected final SynchronousChannel.Queue waitingPuts

waitingTakes	back to summary
protected final SynchronousChannel.Queue waitingTakes

Constructor Detail

SynchronousChannel	back to summary
public SynchronousChannel()

Method Detail

capacity	back to summary
public int capacity() Implements EDU.oswego.cs.dl.util.concurrent.BoundedChannel.capacity. Doc from EDU.oswego.cs.dl.util.concurrent.BoundedChannel.capacity. Return the maximum number of elements that can be held. Returns:int zero -- Synchronous channels have no internal capacity.

capacity

back to summary

public int capacity()

Implements EDU.oswego.cs.dl.util.concurrent.BoundedChannel.capacity.

Doc from EDU.oswego.cs.dl.util.concurrent.BoundedChannel.capacity.

Return the maximum number of elements that can be held.

Returns:int: zero -- Synchronous channels have no internal capacity.

offer	back to summary
public boolean offer(Object x, long msecs) throws InterruptedException Implements EDU.oswego.cs.dl.util.concurrent.Channel.offer. Doc from EDU.oswego.cs.dl.util.concurrent.Channel.offer. Place item in channel only if it can be accepted within msecs milliseconds. The time bound is interpreted in a coarse-grained, best-effort fashion. Parameters x:Object the element to be inserted. Should be non-null. msecs:long the number of milliseconds to wait. If less than or equal to zero, the method does not perform any timed waits, but might still require access to a synchronization lock, which can impose unbounded delay if there is a lot of contention for the channel. Returns:boolean true if accepted, else false Exceptions InterruptedException: if the current thread has been interrupted at a point at which interruption is detected, in which case the element is guaranteed not to be inserted (i.e., is equivalent to a false return).

offer

back to summary

public boolean offer(Object x, long msecs) throws InterruptedException

Implements EDU.oswego.cs.dl.util.concurrent.Channel.offer.

Doc from EDU.oswego.cs.dl.util.concurrent.Channel.offer.

Place item in channel only if it can be accepted within msecs milliseconds. The time bound is interpreted in a coarse-grained, best-effort fashion.

Parameters

x:Object: the element to be inserted. Should be non-null.
msecs:long: the number of milliseconds to wait. If less than or equal to zero, the method does not perform any timed waits, but might still require access to a synchronization lock, which can impose unbounded delay if there is a lot of contention for the channel.

Returns:boolean

true if accepted, else false

Exceptions

InterruptedException:: if the current thread has been interrupted at a point at which interruption is detected, in which case the element is guaranteed not to be inserted (i.e., is equivalent to a false return).

peek	back to summary
public Object peek() Implements EDU.oswego.cs.dl.util.concurrent.Channel.peek. Doc from EDU.oswego.cs.dl.util.concurrent.Channel.peek. Return, but do not remove object at head of Channel, or null if it is empty. Returns:Object null -- Synchronous channels do not hold contents unless actively taken

peek

back to summary

public Object peek()

Implements EDU.oswego.cs.dl.util.concurrent.Channel.peek.

Doc from EDU.oswego.cs.dl.util.concurrent.Channel.peek.

Return, but do not remove object at head of Channel, or null if it is empty.

Returns:Object: null -- Synchronous channels do not hold contents unless actively taken

poll	back to summary
public Object poll(long msecs) throws InterruptedException Implements EDU.oswego.cs.dl.util.concurrent.Channel.poll. Doc from EDU.oswego.cs.dl.util.concurrent.Channel.poll. Return and remove an item from channel only if one is available within msecs milliseconds. The time bound is interpreted in a coarse grained, best-effort fashion. Parameters msecs:long the number of milliseconds to wait. If less than or equal to zero, the operation does not perform any timed waits, but might still require access to a synchronization lock, which can impose unbounded delay if there is a lot of contention for the channel. Returns:Object some item, or null if the channel is empty. Exceptions InterruptedException: if the current thread has been interrupted at a point at which interruption is detected, in which case state of the channel is unchanged (i.e., equivalent to a null return).

poll

back to summary

public Object poll(long msecs) throws InterruptedException

Implements EDU.oswego.cs.dl.util.concurrent.Channel.poll.

Doc from EDU.oswego.cs.dl.util.concurrent.Channel.poll.

Return and remove an item from channel only if one is available within msecs milliseconds. The time bound is interpreted in a coarse grained, best-effort fashion.

Parameters

msecs:long: the number of milliseconds to wait. If less than or equal to zero, the operation does not perform any timed waits, but might still require access to a synchronization lock, which can impose unbounded delay if there is a lot of contention for the channel.

Returns:Object

some item, or null if the channel is empty.

Exceptions

InterruptedException:: if the current thread has been interrupted at a point at which interruption is detected, in which case state of the channel is unchanged (i.e., equivalent to a null return).

put	back to summary
public void put(Object x) throws InterruptedException Implements EDU.oswego.cs.dl.util.concurrent.Channel.put. Doc from EDU.oswego.cs.dl.util.concurrent.Channel.put. Place item in the channel, possibly waiting indefinitely until it can be accepted. Channels implementing the BoundedChannel subinterface are generally guaranteed to block on puts upon reaching capacity, but other implementations may or may not block. Parameters x:Object the element to be inserted. Should be non-null. Exceptions InterruptedException: if the current thread has been interrupted at a point at which interruption is detected, in which case the element is guaranteed not to be inserted. Otherwise, on normal return, the element is guaranteed to have been inserted.

put

back to summary

public void put(Object x) throws InterruptedException

Implements EDU.oswego.cs.dl.util.concurrent.Channel.put.

Doc from EDU.oswego.cs.dl.util.concurrent.Channel.put.

Place item in the channel, possibly waiting indefinitely until it can be accepted. Channels implementing the BoundedChannel subinterface are generally guaranteed to block on puts upon reaching capacity, but other implementations may or may not block.

Parameters

x:Object: the element to be inserted. Should be non-null.

Exceptions

InterruptedException:: if the current thread has been interrupted at a point at which interruption is detected, in which case the element is guaranteed not to be inserted. Otherwise, on normal return, the element is guaranteed to have been inserted.

take	back to summary
public Object take() throws InterruptedException Implements EDU.oswego.cs.dl.util.concurrent.Channel.take. Doc from EDU.oswego.cs.dl.util.concurrent.Channel.take. Return and remove an item from channel, possibly waiting indefinitely until such an item exists. Returns:Object some item from the channel. Different implementations may guarantee various properties (such as FIFO) about that item Exceptions InterruptedException: if the current thread has been interrupted at a point at which interruption is detected, in which case state of the channel is unchanged.

take

back to summary

public Object take() throws InterruptedException

Implements EDU.oswego.cs.dl.util.concurrent.Channel.take.

Doc from EDU.oswego.cs.dl.util.concurrent.Channel.take.

Return and remove an item from channel, possibly waiting indefinitely until such an item exists.

Returns:Object

some item from the channel. Different implementations may guarantee various properties (such as FIFO) about that item

Exceptions

InterruptedException:: if the current thread has been interrupted at a point at which interruption is detected, in which case state of the channel is unchanged.

EDU.oswego.cs.dl.util.concurrent back to summary

protected Class SynchronousChannel.Queue

Class Inheritance

extends Object

java.lang.Object
EDU.oswego.cs.dl.util.concurrent.SynchronousChannel.Queue

Simple FIFO queue class to hold waiting puts/takes.

Field Summary

Modifier and Type	Field and Description
protected LinkedNode	head
protected LinkedNode	last

Constructor Summary

Access	Constructor and Description
protected	Queue()

Method Summary

Modifier and Type	Method and Description
protected LinkedNode	deq()
protected void	enq(LinkedNode p)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

head	back to summary
protected LinkedNode head

last	back to summary
protected LinkedNode last

Constructor Detail

Queue	back to summary
protected Queue()

Method Detail

deq	back to summary
protected LinkedNode deq()

enq	back to summary
protected void enq(LinkedNode p)

public Class SynchronousChannel

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

protected Class SynchronousChannel.Queue

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail