wait_for（）超时之后，是继续阻塞；还是执行后续语句 ？

Question

std::unique_lock<std::mutex>my_lc(my_mutex);my_cond.wait_for(my_lc, std::chrono::milliseconds(10000));

Answer 1

根据c++源码看，超时后会退出阻塞，继续执行后续代码
template <class Rep, class Period>
cv_status wait_for (unique_lock<mutex>& lck,
const chrono::duration<Rep,Period>& rel_time);
return wait_until (lck,chrono::steady_clock::now() + rel_time, std::move(pred));
带谓词
template <class Rep, class Period, class Predicate>
bool wait_for (unique_lock<mutex>& lck,
const chrono::duration<Rep,Period>& rel_time, Predicate pred);
while (!pred())
if (wait_until(lck,abs_time) == cv_status::timeout) 
return pred();//超时后调用谓词并返回结果，true or false
return true;

 

Answer 2

如果没有获取到，仍然处于阻塞状态