哲学家进餐问题的c语言代码

来源：互联网发布：无间道3电影解析知乎编辑：程序博客网时间：2024/04/30 15:36

#include <pthread.h>#include <stdio.h>#define N 5#define LEFT (i+N-1)%N#define RIGHT (i+1)%N#define THINK_TIME 3#define EAT_TIME 2enum { THINKING, HUNGRY, EATING } state[N];pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER, s[N];void test(int i){    if (state[i] == HUNGRY     && state[LEFT] != EATING     && state[RIGHT] != EATING)    {        state[i] = EATING;        pthread_mutex_unlock(&s[i]);    }}void take_forks(int i){    pthread_mutex_lock(&mutex);    state[i] = HUNGRY;    test(i);    pthread_mutex_unlock(&mutex);    pthread_mutex_lock(&s[i]);}void put_forks(int i){    pthread_mutex_lock(&mutex);    state[i] = THINKING;    test(LEFT);    test(RIGHT);    pthread_mutex_unlock(&mutex);}void think(int i){    printf("philosopher %d is thinking...\n", i);    sleep(THINK_TIME);}void eat(int i){    printf("philosopher %d is eating...\n", i);    sleep(EAT_TIME);}void* phi(void* vargp){    int i = *(int*)vargp;    while (1)    {        think(i);        take_forks(i);        eat(i);        put_forks(i);    }    return NULL;}int main(){    int i;    pthread_t tid[N];    for (i = 0; i < N; i++)        pthread_create(&tid[i], NULL, phi, (void*)(&i));    for (i = 0; i < N; i++)        pthread_join(tid[i], NULL);    return 0;}

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