Class BufferQueue

java.lang.Object
  |
  +--BufferQueue

public class BufferQueue

extends java.lang.Object

An object of class BufferQueue is a named queue of Buffers used by a BoundedBufferProcess. The name is established when the BufferQueue is constructed. It can be retrieved by calling toString(). When a BufferQueue is constructed, its capacity is established. It can be filled immediately afterward by calling fill(). If the BufferQueue is not full then a Buffer can be added by calling putBuffer(). Buffers can be retrieved by calling getBuffer(). This method does not return until there is an available Buffer in the BufferQueue.

Field Summary

protected Buffer[]	buffers buffers is the array of Buffers for this BufferQueue.
protected int	capacity capacity is the maximum number of Buffers that this BufferQueue can hold.
protected int	count count is the number of Buffers in this BufferQueue.
protected java.lang.String	name name is the name for this BufferQueue.
protected int	nextGet nextGet is the index where the next available Buffer can be found in this BufferQueue.

Constructor Summary

BufferQueue(java.lang.String nm, int n)
new BufferQueue(nm, n) returns a new BufferQueue with a capacity for n Buffer objects.

Method Summary

void	fill() bq.fill() fills bq with Buffers whose names are the decimal representations of integers from 0 up to one less than the capacity of bq.
Buffer	getBuffer() bq.getBuffer() returns the next available Buffer from bq.
boolean	isFull() bq.isFull() returns true if there is no more room for Buffers in bq.
void	putBuffer(Buffer buff) bq.putBuffer(buff) adds buff to bq.
java.lang.String	toString() bq.toString() returns the name of bq.

Methods inherited from class java.lang.Object

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

Field Detail

buffers

protected Buffer[] buffers

buffers is the array of Buffers for this BufferQueue.

capacity

protected int capacity

capacity is the maximum number of Buffers that this BufferQueue can hold.

count

protected int count

count is the number of Buffers in this BufferQueue.

nextGet

protected int nextGet

nextGet is the index where the next available Buffer can be found in this BufferQueue.

name

protected java.lang.String name

name is the name for this BufferQueue.

Constructor Detail

BufferQueue

public BufferQueue(java.lang.String nm,
                   int n)

new BufferQueue(nm, n) returns a new BufferQueue with a capacity for n Buffer objects. The name of the new BufferQueue is formed by concatenating its class name with nm.

Method Detail

fill

public void fill()

bq.fill() fills bq with Buffers whose names are the decimal representations of integers from 0 up to one less than the capacity of bq.

isFull

public boolean isFull()

bq.isFull() returns true if there is no more room for Buffers in bq.

getBuffer

public Buffer getBuffer()

bq.getBuffer() returns the next available Buffer from bq. If bq is empty then getBuffer() does not return until there is an available Buffer.

putBuffer

public void putBuffer(Buffer buff)

bq.putBuffer(buff) adds buff to bq. Preconditions: bq.isFull() is false.

toString

public java.lang.String toString()

bq.toString() returns the name of bq.

Overrides:

toString in class java.lang.Object