int n;

int cur;

sem_t sem_fizz;

sem_t sem_buzz;

sem_t sem_fizz_buzz; // 这三个信号量分别用于线程的同步

sem_t sem_num; // 用于触发数字增加

FizzBuzz(int n) {

this->n = n;

cur = 0;

sem_init(&sem_fizz, 0, 0);

sem_init(&sem_buzz, 0, 0);

sem_init(&sem_fizz_buzz, 0, 0); // 这三者的信号量初始化都置位为0，三个线程均被阻塞

sem_init(&sem_num, 0, 1); // 初始化信号量为1，触发开始

}

// printFizz() outputs "fizz".

void fizz(function<void()> printFizz) {

while (cur <= n) {

sem_wait(&sem_fizz); // 等待信号量为1

if (cur > n) break;

printFizz();

sem_post(&sem_num); // 将信号量sem_num加1,变为1

}

}

// printBuzz() outputs "buzz".

void buzz(function<void()> printBuzz) {

while (cur <= n) {

sem_wait(&sem_buzz);

if (cur > n) break;

printBuzz();

sem_post(&sem_num);

}

}

// printFizzBuzz() outputs "fizzbuzz".

void fizzbuzz(function<void()> printFizzBuzz) {

while (cur <= n) {

sem_wait(&sem_fizz_buzz);

if (cur > n) break;

printFizzBuzz();

sem_post(&sem_num);

}

}

// printNumber(x) outputs "x", where x is an integer.

void number(function<void(int)> printNumber) {

while (++cur <= n) {

sem_wait(&sem_num); // 等待信号量sem_num变为1

if (cur % 3 == 0 && cur % 5 == 0) {

sem_post(&sem_fizz_buzz); // 将sem_fizz_buzz置为1

} else if (cur % 3 == 0) {

sem_post(&sem_fizz); // 将sem_fizz置为1

} else if (cur % 5 == 0) {

sem_post(&sem_buzz); // 将sem_buzz置为1

} else {

printNumber(cur);

sem_post(&sem_num); // 将sem_num置为1

}

}

// 以下三个post通过更新sem_fizz等信号量，调动其他线程运行，进而结束所有线程

sem_post(&sem_fizz);

sem_post(&sem_buzz);

sem_post(&sem_fizz_buzz);

}

FizzBuzz fizzBuzz(15);

std::function<void()> printFizz = []() { cout << " fizz " << endl; };

std::function<void()> printBuzz = []() { cout << " buzz " << endl; };

std::function<void()> printFizzBuzz = []() { cout << " fizzbuzz " << endl; };

std::function<void(int)> printNum = [](int x) { cout << x << endl; };

std::thread th[4];

th[0] = std::thread(&FizzBuzz::fizz, &fizzBuzz, printFizz);

th[1] = std::thread(&FizzBuzz::buzz, &fizzBuzz, printBuzz);

th[2] = std::thread(&FizzBuzz::fizzbuzz, &fizzBuzz, printFizzBuzz);

th[3] = std::thread(&FizzBuzz::number, &fizzBuzz, printNum);

for (auto& ts : th) {

if (ts.joinable()) ts.join();

}

return 0;