class Condition3 : public ConditionBase
{
public:
    Condition3()
        : signal_(false)
    {
    }
 
    void wait()
    {
        pthread_mutex_lock(&mutex_);
        if (!signal_)
        {
            pthread_cond_wait(&cond_, &mutex_);
        }
        signal_ = false;
        pthread_mutex_unlock(&mutex_);
    }
 
    void wakeup()
    {
        pthread_mutex_lock(&mutex_);
        signal_ = true;
        pthread_cond_signal(&cond_);
        pthread_mutex_unlock(&mutex_);
    }
 
private:
    bool signal_;
};