我想知道工人只有在客户要求邮寄包裹时才能获得规模。这是50个客户访问邮局（每个客户1个线程，最多50个），所有这些都是最初创建的。一次只有10个客户可以进入邮局。每个客户在创建时被随机分配以下任务之一：购买邮票，邮寄信件，邮寄包裹。在邮寄包裹时，邮政工作人员使用该比例。只有一个，一次只能使用一个。尺度不是线程。它们只是邮政工作者线程使用的资源。我有以下代码：
class Customer extends Thread {
/* we create the integer iD which is a unique ID number for every worker
and a boolean notServed which is used in the Customer waiting loop */
int iD;
int bG;
Semaphore sem;
boolean notServed=true;
/* Constructor for the Customer */
public Customer(int i, int b, Semaphore s) {
iD = i;
bG = b;
sem = s;
}
public void run() {
while (notServed) { // as long as the worker is not cut
try {
accessSpots.acquire(); //tries to get access to the rooms
if (numberOfAvailRoom > 0) { //if there are any free rooms
System.out.println("Customer " + this.iD + " enter post office ");
try {
sleep(1000);
} catch (InterruptedException ex){ }
numberOfAvailRoom--; //room is taken
sem.release(); //notify the worker that there is a worker
help.release();
try {
workers.acquire(); // now it's this customers turn but we have to wait if the worker is busy
notServed = false; // this worker will now leave after the procedure
if (bG == 1)
{
System.out.println("Customer "+this.iD+" ask postal worker to buy stamp");
buyStamp();
help.release();
workers.release();
try {
sleep(1000);
} catch (InterruptedException ex){ }
}
else if (bG == 2)
{
System.out.println("Customer "+this.iD+" ask postal worker to mail letter");
mailLetter();
help.release();
workers.release();
try {
sleep(1000);
} catch (InterruptedException ex){ }
}
else if (bG == 3)
{
//scale.release();
System.out.println("Customer "+this.iD+" ask postal worker to mail package");
//scale.release();
mailPackage();
help.release();
workers.release();
//scale.release();
try {
sleep(1000);
} catch (InterruptedException ex){ }
//bellHops.acquire();
}
} catch (InterruptedException ex) {}
}
else { // there are no free rooms
//System.out.println("There are no available room. Customer " + this.iD + " has left the workershop.");
accessSpots.release(); //release the lock on the rooms
notServed=true; // .
}
}
catch (InterruptedException ex) {}
}
}
/* this method will simulate getting a hair-cut */
public void buyStamp(){
System.out.println("Customer " + this.iD+" finished buying stamp" );
try {
sleep(1000);
} catch (InterruptedException ex) {}
sem.release();
leave();
}
public void mailLetter(){
//i = a;
System.out.println("Customer " + this.iD + " finished mailing letter ");
try {
sleep(1500);
} catch (InterruptedException ex) {}
sem.release();
leave();
}
public void mailPackage(){
//i = a;
scale.release();
System.out.println("Customer " + this.iD + " finished mailing package ");
try {
sleep(2000);
} catch (InterruptedException ex) {}
sem.release();
leave();
}
public void leave()
{
System.out.println("Customer "+this.iD+" left the post office ");
}
}
/* THE EMPLOYEE THREAD */
class Worker extends Thread {
int iD;
Semaphore sem;
//int bG
public Worker(int a, Semaphore s)
{
iD = a;
sem = s;
//bG = b;
}
public void run() {
while(true) { // runs in an infinite loop
try {
customers.acquire(); // tries to acquire the next avail customer
accessSpots.release(); // at this time he has been awaken -> want to modify the number of available rooms
numberOfAvailRoom++; // one room gets free
int a = numberOfAvailRoom;
System.out.println("Postal Worker "+this.iD +" serving cutomer ");
workers.release(); // the worker is ready
accessSpots.release(); // we don't need the lock on the room anymore
//help.acquire();
//scale.acquire();
this.Scale();
//scaleRelease();
//int a = gNum;
//this.Finished(); //cutting...
} catch (InterruptedException ex) {}
}
}
public void Scale(){
try
{
scale.acquire();
System.out.println("Scale in use by Postal Worker "+this.iD);
this.scaleRelease();
}catch (InterruptedException ex){}
}
public void scaleRelease(){
//try
//{
//rel.acquire();
System.out.println("Scale released by Postal Worker "+this.iD);
//}catch (InterruptedException ex){}
}
public void Finished(){
System.out.println("Postal Worker "+this.iD+" finished serving customer ");
//done.release();
}
}