muduo库源码学习(base)CountDownLatch

#ifndef MUDUO_BASE_COUNTDOWNLATCH_H#define MUDUO_BASE_COUNTDOWNLATCH_H#include "./Condition.h"#include "./Mutex.h"#include <boost/noncopyable.hpp>namespace muduo{class CountDownLatch : boost::noncopyable//CountDownLatch作为成员的计数器使用{ public:  explicit CountDownLatch(int count);  void wait();  void countDown();  int getCount() const; private:  mutable MutexLock mutex_;  Condition condition_;  int count_;};}#endif  // MUDUO_BASE_COUNTDOWNLATCH_H

#include "./CountDownLatch.h"using namespace muduo;CountDownLatch::CountDownLatch(int count)  : mutex_(),    condition_(mutex_),    count_(count){}void CountDownLatch::wait(){  MutexLockGuard lock(mutex_);  while (count_ > 0)  {    condition_.wait();  }}void CountDownLatch::countDown(){  MutexLockGuard lock(mutex_);  --count_;  if (count_ == 0)//一旦目标线程全部开启，发送信号使等待中的线程解锁  {    condition_.notifyAll();  }}int CountDownLatch::getCount() const{  MutexLockGuard lock(mutex_);  return count_;}