C++11并发编程:多线程std::thread

2020-01-06 20:01:57丽君

交换两个线程对象


thread t1(threadFun1);
thread t2(threadFun2);
cout << "线程1的ID:" << t1.get_id() << endl;
cout << "线程2的ID:" << t2.get_id() << endl;
t1.swap(t2);
cout << "线程1的ID:" << t1.get_id() << endl;
cout << "线程2的ID:" << t2.get_id() << endl;

5.hardware_concurrency()

获得逻辑处理器储量,返回值为int型


int coreNum = thread::hardware_concurrency();

四:使用

1.创建线程


void threadFun1()
{
  cout << "this is thread fun1 !" << endl;
}
int main()
{
  thread t1(threadFun1);
  t1.join();
  getchar();
  return 1;
}

2.创建线程,传参


void threadFun1(int v)
{
  cout << "this is thread fun1 !" << endl;
  cout << v << endl;
}
int main()
{
  int value = 6;
  thread t1(threadFun1, value);
  t1.join();
  getchar();
  return 1;
}

需要注意,变量int value 和int v 做变量传递时并不是引用,而是对变量做了拷贝,所以在传递给int v前,int value不能出作用域(释放了内存),join(),可以保证int value变量释放内存,如果使用detach(),可能存在这种情况。

3.创建线程,引用传参


void threadFun1(int& v)
{
  cout << "this is thread fun1 !" << endl;
  cout << v << endl;
}
int main()
{
  int value = 6;
  thread t1(threadFun1, std::ref(value));
  t1.join();
  getchar();
  return 1;
}

4.创建建线程,线程函数为类成员函数