我发一个C#做的就餐问题的模拟程序， 用 5 个线程模拟 5 个哲学家。
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
namespace Philosopher
{
class Fork
{
const int NOBODY = -1;
int Owner = NOBODY;
public Fork() { }
public bool IsTakenBy(Philosopher p) { return p.ID == Owner; }
public void TakenBy(Philosopher p)
{
if (Owner == NOBODY)
Owner = p.ID;
}
public void PutBy(Philosopher p)
{
if (p.ID == Owner)
Owner = NOBODY;
}
}
class Philosopher
{
bool ThreadRunning;
Thread DinningThread;
public int ID;
public Fork Left;
public Fork Right;
public Philosopher(int id, Fork left, Fork right)
{
ID = id;
Left = left;
Right = right;
DinningThread = new Thread(StartDinning);
DinningThread.Start();
}
public void Think() { Thread.Sleep(1000); }
public void Dine()
{
lock (this) {
Left.TakenBy(this);
Right.TakenBy(this);
}
if (Left.IsTakenBy(this) && Right.IsTakenBy(this)) {
Console.WriteLine("Philosopher " + ID.ToString() + " is dining.");
Thread.Sleep(1000);
}
lock (this) {
Left.PutBy(this);
Right.PutBy(this);
}
}
public void Stop() { ThreadRunning = false; }
void StartDinning()
{
ThreadRunning = true;
while (ThreadRunning) {
Think();
Dine();
}
}
}
class Program
{
static void Main(string[] args)
{
Fork[] forks = new Fork[] { new Fork(), new Fork(), new Fork(), new Fork(), new Fork() };
Philosopher[] philosophers = new Philosopher[5];
for (int i = 0; i < 5; i++) {
philosophers[i] = new Philosopher(i, forks[i], forks[(i + 4) % 5]);
}
Console.Read();
for (int i = 0; i < 5; i++)
philosophers[i].Stop();
}
}
}
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