操作系统经典同步互斥问题——哲学家就餐

#include <iostream>#include <mutex>#include <cstdio>#include <thread>#include <semaphore.h>using namespace std;#define THINK(i) PRintf("ph[%d] is thinking.../n", i)#define EAT(i) printf("ph[%d] eats./n", i)void P(mutex &mt){    mt.lock();}void V(mutex &mt){    mt.unlock();}void P(sem_t* sem){    if(sem_wait(sem))        perror("P error!");}void V(sem_t* sem){    if(sem_post(sem))        perror("V error!");}// 加入unistd.h出现问题，似乎与thread的兼容性比较差，于是重写void delay(){    int sum=0;    for(int i = 0; i < 10000000; i++)        sum += i;}mutex fork[5];sem_t room;void init(){    sem_init(&room, 0, 4);}void philosopher (int i){    for(int j = 0; j < 5; j++)    {        THINK(i);        P(&room);        P(fork[i]);        P(fork[(i+1)%5]);        EAT(i);        V(&room);        V(fork[i]);        V(fork[(i+1)%5]);    }}int main(){    init();    thread t[] = {        thread(philosopher, 0),        thread(philosopher, 1),        thread(philosopher, 2),        thread(philosopher, 3),        thread(philosopher, 4),    };                for(int k = 0; k < 5; k++)        t[k].join();        return 0;}