/**
* @version 1.20 2002-09-12
* @author shengxiang@wang
*/
public class TestPV
{
public static void main(String[] args)
{
TestPV main = new TestPV();
}
public TestPV()
{
ReadThread readTh = null;
WriteThread writeTh = null;
readTh = new ReadThread("Read1");
readTh.start();
readTh = new ReadThread("Read2");
readTh.start();
readTh = new ReadThread("Read3");
readTh.start();
readTh = new ReadThread("Read4");
readTh.start();
readTh = new ReadThread("Read5");
readTh.start();
readTh = new ReadThread("Read6");
readTh.start();
writeTh = new WriteThread("Write1");
writeTh.start();
writeTh = new WriteThread("Write2");
writeTh.start();
}
public static int m_nGlobal = 0;
public static Signal m_Full = new Signal(0);
public static Signal m_Empty = new Signal(100);
public static Signal m_Mutex = new Signal(1);
}
class ReadThread extends Thread
{
public ReadThread(String sName)
{
super();
m_sName = sName;
}
public void run()
{
while (!interrupted())
{
try
{
TestPV.m_Full.pAction();
TestPV.m_Mutex.pAction();
TestPV.m_nGlobal--;
System.out.println("ThreadName: " + m_sName + "Global value:" + TestPV.m_nGlobal);
TestPV.m_Mutex.vAction();
TestPV.m_Empty.vAction();
sleep(1);
}
catch(InterruptedException ex)
{
break;
}
}// while
}
private String m_sName;
}
class WriteThread extends Thread
{
public WriteThread(String sName)
{
super();
m_sName = sName;
}
public void run()
{
while (!interrupted())
{
try
{
TestPV.m_Empty.pAction();
TestPV.m_Mutex.pAction();
TestPV.m_nGlobal++;
System.out.println("ThreadName: " + m_sName + "Global value:" + TestPV.m_nGlobal);
TestPV.m_Mutex.vAction();
TestPV.m_Full.vAction();
sleep(1);
}
catch(InterruptedException ex)
{
break;
}
}// while
}
private String m_sName;
}
final class Signal
{
protected Signal()
{
this(1);
}
protected Signal(int nInit)
{
m_nCounter = nInit;
}
public final synchronized void pAction()
throws InterruptedException
{
m_nCounter--;
if(m_nCounter<0) wait(0);
}
public final synchronized void vAction()
{
m_nCounter++;
if(m_nCounter<=0) notify();
}
private int m_nCounter = 0;
}
