leetcode线程题1117——H2O 生成（两个氢原子结合一个氧原子）

#include<semaphore.h>
class H2O {
public:
    H2O() {
        sem_init(&mutex1,0,1);
        sem_init(&mutex2,0,1);
        count = 0;
    }
    void hydrogen(function<void()> releaseHydrogen) {
        sem_wait(&mutex1);
        count++;
        releaseHydrogen();
        if(count % 2 == 0)
        {  
            sem_post(&mutex2);
        }
        else
        {
            sem_post(&mutex1);
        }
        // releaseHydrogen() outputs "H". Do not change or remove this line.
        // releaseHydrogen();
    }
    void oxygen(function<void()> releaseOxygen) {
        sem_wait(&mutex2);
        // releaseOxygen() outputs "O". Do not change or remove this line.
        releaseOxygen();
        sem_post(&mutex1);
    }
    sem_t mutex1;
    sem_t mutex2;
    int count;
};