Question

I have the following lines of code where I used C++ Boost thread:

void threadFunc()
{
boost::mutex::scoped_lock lock(m_Mutex);
//some code here...
condition.notify_one();
} 

So should I call unlock() function before the last line, like the following? What is the difference if I don’t call unlock()?

void threadFunc()
{
boost::mutex::scoped_lock lock(m_Mutex);
//some code here...
lock.unlock();
condition.notify_one();
} 

Answer 1

No — the point of the scoped_lock class is that the lock is tied to the scope — i.e., when the scoped_lock object goes out of scope, the lock is automatically released. This assures (for example) that if any of the intervening code throws an exception, the lock will still be released.