Class SharedData

java.lang.Object
  |
  +--SharedData

public class SharedData

extends java.lang.Object

An object of class SharedData is a named int data value used by a SharedDataProcess. The name is established when the SharedData is constructed. It can be retrieved by calling toString().

An object reading from or writing to a SharedData object takes a fixed amount of time to complete the operation. This access time is specified in the SharedDataconstructor.

When a SharedData is constructed, its value is initialized to 0. Its value is incremented by calling write(). Its value can be read by calling read(). Writers have precedence over Readers. No Reader can read the value while Writers are waiting to write the value.

Field Summary

protected static long	accessTime accessTime is the time required to perform a data access on this SharedData.
protected Locker	locker locker provides the Writer locking and Reader waiting for this SharedData.
protected java.lang.String	name name is the name for this SharedData.
protected int	value value is the current value of this SharedData.

Constructor Summary

SharedData(java.lang.String nm, double t)
new SharedData(nm, t) returns a new SharedData object.

Method Summary

protected void	doWrite() doWrite() increments the value of this Writer.
void	read() sd.read() reads the current value of sd.
java.lang.String	toString() sd.toString() returns the name of sd.
void	write() sd.write() increments the value of sd.

Methods inherited from class java.lang.Object

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

Field Detail

value

protected int value

value is the current value of this SharedData.

accessTime

protected static long accessTime

accessTime is the time required to perform a data access on this SharedData.

locker

protected Locker locker

locker provides the Writer locking and Reader waiting for this SharedData.

name

protected java.lang.String name

name is the name for this SharedData.

Constructor Detail

SharedData

public SharedData(java.lang.String nm,
                  double t)

new SharedData(nm, t) returns a new SharedData object. The name of the new SharedData is formed by concatenating its class name with nm. Its access time is t.

Method Detail

read

public void read()

sd.read() reads the current value of sd. This method does not complete until there are no Writers waiting to write to sd.

write

public void write()

sd.write() increments the value of sd.

toString

public java.lang.String toString()

sd.toString() returns the name of sd.

Overrides:

toString in class java.lang.Object

doWrite

protected void doWrite()

doWrite() increments the value of this Writer.