完整的哲学家进食代码

完整的哲学家进食代码

//#include "stdafx.h"
#include <windows.h>  //HADNDLE
#include <process.h>
//#include <time.h>  //time(0)
//#include <stdlib.h>
#include "iostream"using namespace std;const unsigned int N=2;    //哲学家数目
const int THINKING=1;     //标记当前哲学家的状态,1表示思考(饱的)
const int HUNGRY=2;      //2表示得到饥饿,3表示正在吃饭
const int DINING=3;HANDLE hPhilosopher[N];  
HANDLE semaphore[N];HANDLE mutex;   //typedef void* HANDLE, 用于输出DWORD WINAPI philosopherProc(LPVOID lpParameter) //返回DWORD(32位数据)的API函数
//typedef unsigned long DWORD 
//typedef WINAPI __stdcall 函数参数入栈方式从右到左,一般导出函数时用。
//typedef void* LPVOID
{char stateStr[128];int ret;unsigned int leftFork;  //左右筷子unsigned int rightFork;int myid = int(lpParameter);WaitForSingleObject(mutex, INFINITE);	//安全输出						cout << "philosopher" << myid << " " << endl;ReleaseMutex(mutex);int mystate = THINKING;  //初始状态在思考leftFork = (myid)%N;rightFork = (myid+1)%N;while(true)   //注意这里的while(true)，也就是说，它一直在这几种状态之间转换。{switch(mystate)   //状态的转变{case THINKING:mystate = HUNGRY;	//thinking直接转hungrystrcpy(stateStr, "HUNGRY");break;case HUNGRY:strcpy(stateStr, "HUNGRY");ret = WaitForSingleObject(semaphore[leftFork], //先看左手0);//第二个参数，等待时间if(ret == WAIT_OBJECT_0){ret = WaitForSingleObject(semaphore[rightFork],0);if (ret == WAIT_OBJECT_0){mystate = DINING;strcpy(stateStr, "DINING");}elseReleaseSemaphore(semaphore[leftFork],1,NULL);}break;case DINING:ReleaseSemaphore(semaphore[leftFork],1,NULL);ReleaseSemaphore(semaphore[rightFork],1,NULL);mystate = THINKING;strcpy(stateStr, "THINKING");break;}WaitForSingleObject(mutex, INFINITE);//安全输出，保证不被抢占cout << "philosopher" << myid << " is: " << stateStr << endl;ReleaseMutex(mutex);//sleep 100msSleep(100);}
}int main()
{//srand(time(0));mutex = CreateMutex(NULL, false, NULL); //创建一个互斥变量for (int i = 0; i < N; i++){semaphore[i] = CreateSemaphore(NULL, 1, 1, NULL); //创建一个新的信号量hPhilosopher[i] = CreateThread(NULL, 0,   //线程安全属性，堆栈大小philosopherProc, LPVOID(i),       //线程函数,线程参数(这里，把i转成LPVOID传递)CREATE_SUSPENDED, 0);   //线程创建属性（这里是挂起，所以下面有唤起），线程ID}for (int i = 0; i < N; i++){ResumeThread(hPhilosopher[i]); //线程恢复函数}Sleep(800);//给时间线程执行return 0;
}

运行结果：

在足够时间下，哲学家的状态是一直在来回转变的，因为while(true)的原因。

可以设置一个状态检查，只要吃过就不要吃了，退出while循环，只吃一次。

cout << "philosopher" << myid << " is: " << stateStr << endl;
ReleaseMutex(mutex);
if (mystate == THINKING) //状态检测，从hungry开始，吃完之后是thinking.结束函数，同时意味着线程的退出。
{return 1;
}
//sleep 100ms
Sleep(100);

OK，先暂时这样。