我使用std :: list來保存一些字符串,一個線程寫入列表和一些其他線程讀取它(獲取第一個和從列表中刪除)。下面的代碼:如何使boost_to_unique_lock + condition_variable提升一起工作?
std::list<string> list_;
boost::condition_variable cond;
boost::shared_mutex mtx;
int get_size() {
boost::shared_lock<boost::shared_mutex> lock(mtx);
return list_.size();
}
// add a string to the list
// invoked by only one thread
void add_one(const string& p) {
{
boost::upgrade_lock<boost::shared_mutex> lock(mtx);
boost::upgrade_to_unique_lock<boost::shared_mutex> uniquelock(lock);
list_.push_back(p);
}
cond.notify_one();
}
// get the first string and remove it from the list
// invoked by many threads
string pick_one() {
string ret;
{
boost::upgrade_lock<boost::shared_mutex> lock(mtx);
boost::upgrade_to_unique_lock<boost::shared_mutex> uniquelock(lock);
if(!list_.size()) { // if empty, wait for notify
cond.wait(uniquelock, [&]{ return list_.size() > 0; }); // compile error
}
ret = list_.front();
list_.pop_front();
}
return ret;
}
有在行cond.wait(uniquelock, ...
什麼用的讀/寫鎖與condition_variable的正確方法編譯錯誤?
似乎'condition_variable_any'應該可以工作,但是如何在沒有'upgrade_to_unique_lock'的情況下創建寫鎖? – aj3423