net.wimpi.modbus.util

Class LinkedQueue

java.lang.Object

net.wimpi.modbus.util.LinkedQueue

public class LinkedQueue
extends Object

The type Linked queue.

Field Summary

Fields

Modifier and Type	Field and Description
protected LinkedNode	m_Head Dummy header node of list.
protected Object	m_PutLock Helper monitor for managing access to last node.
protected LinkedNode	m_Tail The last node of list.
protected int	m_WaitingForTake The number of threads waiting for a take.

Constructor Summary

Constructors

Constructor and Description
LinkedQueue() Instantiates a new Linked queue.

Method Summary

Modifier and Type	Method and Description
protected Object	extract() Main mechanics for take/poll
protected void	insert(Object x) Main mechanics for put/offer
boolean	isEmpty() Is empty boolean.
boolean	offer(Object x, long msecs) Offer boolean.
Object	peek() Peek object.
Object	poll(long msecs) Poll object.
void	put(Object x) Put.
Object	take() Take object.

Methods inherited from class java.lang.Object

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

Field Detail

m_Head

protected LinkedNode m_Head

Dummy header node of list. The first actual node, if it exists, is always at m_Head.m_NextNode. After each take, the old first node becomes the head.

m_PutLock

protected final Object m_PutLock

Helper monitor for managing access to last node.

m_Tail

protected LinkedNode m_Tail

The last node of list. Put() appends to list, so modifies m_Tail_

m_WaitingForTake

protected int m_WaitingForTake

The number of threads waiting for a take. Notifications are provided in put only if greater than zero. The bookkeeping is worth it here since in reasonably balanced usages, the notifications will hardly ever be necessary, so the call overhead to notify can be eliminated.

Constructor Detail

LinkedQueue

public LinkedQueue()

Instantiates a new Linked queue.

Method Detail

insert

protected void insert(Object x)

Main mechanics for put/offer

Parameters:

x - the x

extract

protected Object extract()

Main mechanics for take/poll

Returns:

the object

put

public void put(Object x)
         throws InterruptedException

Put.

Parameters:

x - the x

Throws:

InterruptedException - the interrupted exception

offer

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

Offer boolean.

Parameters:

x - the x

msecs - the msecs

Returns:

the boolean

Throws:

InterruptedException - the interrupted exception

take

public Object take()
            throws InterruptedException

Take object.

Returns:

the object

Throws:

InterruptedException - the interrupted exception

peek

public Object peek()

Peek object.

Returns:

the object

isEmpty

public boolean isEmpty()

Is empty boolean.

Returns:

the boolean

poll

public Object poll(long msecs)
            throws InterruptedException

Poll object.

Parameters:

msecs - the msecs

Returns:

the object

Throws:

InterruptedException - the interrupted exception