我的程序处于死锁状态,我不知道为什么,当我在调试器中运行它时不会这样做,所以我的第一个疑犯是我的rwLock,我写了自己的版本,因为我只想使用标准库 - 我不认为直到C++ 17才包含rwLock - 这不是我通常所做的事情。这个rwLock实现有什么问题吗?
class RwLock
{
std::mutex mutex;
std::unique_lock<std::mutex> unique_lock;
std::condition_variable condition;
int reading_threads;
bool writing_threads;
public:
RwLock();
~RwLock();
void read_lock();
void read_unlock();
void write_lock();
void write_unlock();
};
RwLock::RwLock() :
mutex(),
unique_lock(mutex, std::defer_lock),
condition(),
reading_threads(0),
writing_threads(false)
{
}
RwLock::~RwLock()
{
//TODO: find something smarter to do here.
write_lock();
}
void RwLock::read_lock()
{
unique_lock.lock();
while(writing_threads)
{
condition.wait(unique_lock);
}
++reading_threads;
unique_lock.unlock();
}
void RwLock::read_unlock()
{
unique_lock.lock();
if(--reading_threads == 0)
{
condition.notify_all();
}
unique_lock.unlock();
}
void RwLock::write_lock()
{
unique_lock.lock();
while(writing_threads)
{
condition.wait(unique_lock);
}
writing_threads = 1;
while(reading_threads)
{
condition.notify_all();
}
unique_lock.unlock();
}
void RwLock::write_unlock()
{
unique_lock.lock();
writing_threads = 0;
condition.notify_all();
unique_lock.unlock();
}
'while(reading_threads){condition.notify_all(); “如果有任何读者,这将永远等待。你永远不会解锁锁,因此永远不会给读者一个减少'read_threads'的机会。看起来像复制/粘贴到我的错误 - 我敢打赌,你的意思是'condition.wait'在这里,而不是'notify_all' –
@IgorTandetnik我从另一个网站复制了这个,并修改它,所以是的。我有一种感觉,那就是问题的原因,但这两种情况对我来说都不会对我产生很大的影响。 –
'shared_timed_mutex'存在于C++ 14中 – Yakk