算法设计原理:
(a)系统生成五位哲学家以及五根筷子chopsticks[5],每根筷子都是临界资源,所以我们用五个信号量semaphore来描述这五根筷子。
(b)为了确保始终有哲学家能够吃上饭,我规定奇数号哲学家先拿他左边的筷子,然后再去拿他右边的筷子;而偶数号哲学家则要先去拿他右边的筷子,再去那他左边的筷子。
伪代码:
semaphore chopsticks[5]={1,1,1,1,1};
while(TRUE){
for (int i=0;i<5;i++){
…
//think
…
if((i+1)%2==1){
Swait(chopsticks[i],chopsticks[(i+1)%5];
…
//eat
…
Signal(chopsticks[i],chopsticks[(i+1)%5])
}
else{
Swait(chopsticks[(i+1)%5],chopsticks[i]);
…
//eat
…
Signal(chopsticks[(i+1)%5],chopsticks[i]];
}
}
}
完整代码:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;
namespace philosopher
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
chopsticks1 = new Semaphore(1, 1);
chopsticks2 = new Semaphore(1, 1);
chopsticks3 = new Semaphore(1, 1);
chopsticks4 = new Semaphore(1, 1);
chopsticks5 = new Semaphore(1, 1);
}
private static bool StopFlag = false;
private int philosopherNumber = 5;
private void Form1_Load(object sender, EventArgs e)
{
}
public class TaskInfo
{
public int Index;
public TaskIn