c实现哲学家进餐问题。WINDOWS下。

// 解决哲学家就餐问题// 每个哲学家可用一个线程来模拟。// 设有5个哲学家，5只筷子，每个哲学家吃饭时间为一个随机值，哲学家吃饭后的思考时间也是一个随机值。#include <Windows.h>#include <iostream>#include <cstdio>#include <stdlib.h>#include <time.h>/*（1）奇数号的哲学家先拿起右边的筷子再拿起左边的筷子。

（2）偶数号哲学家先拿起左边的筷子，再拿起右边的筷子。

（3）如果哲学家抢到一只筷子，在抢占另一只筷子时失败，则要放弃已经抢占到的资源。

（4）左右两边都抢到筷子的哲学家，吃完放后释放资源。*/using namespace std;

HANDLE chop[5];HANDLE ph[5];HANDLE mutex;int nums=0;

int random(){ return rand()%100+20;}void eating(int id){ int num=random(); Sleep(num); printf("\t\t\t哲学家%d号吃了%d秒\n",id,num);}

DWORD WINAPI phthread(LPVOID param){ nums++; int id=nums; int lc=id-1; int rc=id%5; int times=0; int ret1,ret2; while(true) { Sleep(100); if (times>=2) break; if (id % 2 == 0) { ret1 = WaitForSingleObject(chop[lc], 0); if (ret1 == WAIT_OBJECT_0) { ret2 = WaitForSingleObject(chop[rc], 0); if (ret2 == WAIT_OBJECT_0) { WaitForSingleObject(mutex,INFINITE); printf("哲学家%d号拿到两只筷子开始吃第%d顿饭。\n", id,times+1); ReleaseMutex(mutex); times++; WaitForSingleObject(mutex,INFINITE); eating(id); ReleaseMutex(mutex); WaitForSingleObject(mutex,INFINITE); printf("\t\t\t哲学家%d号吃完两顿饭啦，放下筷子。\n", id); ReleaseMutex(mutex); ReleaseSemaphore(chop[rc], 1, NULL); } ReleaseSemaphore(chop[lc], 1, NULL); } } else { ret1 = WaitForSingleObject(chop[rc], 0); if (ret1 == WAIT_OBJECT_0) { ret2 = WaitForSingleObject(chop[lc], 0); if (ret2 == WAIT_OBJECT_0) { WaitForSingleObject(mutex,INFINITE); printf("哲学家%d号拿到两只筷子开始吃%d顿饭。\n", id,times+1); ReleaseMutex(mutex); times++; WaitForSingleObject(mutex,INFINITE); eating(id); ReleaseMutex(mutex); WaitForSingleObject(mutex,INFINITE); printf("\t\t\t哲学家%d号吃完两顿饭啦，放下筷子。\n", id); ReleaseMutex(mutex); ReleaseSemaphore(chop[lc], 1, NULL); } ReleaseSemaphore(chop[rc], 1, NULL); } } WaitForSingleObject(mutex,INFINITE); ReleaseMutex(mutex); } printf("=======哲学家%d吃饱了然后离开了。=======\n",id); return 0;

}

int main(){ srand((unsigned)time(0)); mutex = CreateMutex(NULL, false, NULL); for (int i = 0; i < 5; ++i) { chop[i]=CreateSemaphore(NULL,1,1,NULL); } for (int i = 0; i < 5; ++i) { int j = i + 1; ph[i] = CreateThread(NULL, 0, phthread,NULL, 0, NULL); }

 

Sleep(10000);//释放句柄 for (int i = 0; i < 5; ++i) { CloseHandle(ph[i]); CloseHandle(chop[i]); } CloseHandle(mutex); Sleep(500); system("pause"); return 0;}

转载于:https://www.cnblogs.com/ruoh3kou/p/8758069.html

相关资源：操作系统课程设计 哲学家进餐问题（完整C++/MFC源代码+可运行程序+论文）