C++ : Condition variable between checking UI thread & worker thread

I am trying to use an std::condition_variable from C++11 for a data transaction between between UI thread & worker thread.

Situation:
m_calculated_value is a value which calculated after a complex logic. This is required on a trigger of a event from the UI thread. UI thread calls MyClass::GetCalculatedValue to fetch the value of m_calculated_value which needs to be calculated by the worker thread function that is MyClass::ThreadFunctionToCalculateValue.

Code:

std::mutex              m_mutex;
std::condition_variable m_my_condition_variable;
bool                    m_value_ready;
unsigned int            m_calculated_value;


// Gets called from UI thread
unsigned int MyClass::GetCalculatedValue() {

    std::unique_lock<std::mutex> lock(m_mutex);
    m_value_ready = false;

    m_my_condition_variable.wait(lock, std::bind(&MyClass::IsValueReady, this));

    return m_calculated_value;
}


bool MyClass::IsValueReady() {

    return m_value_ready;
}

// Gets called from an std::thread or worker thread
void MyClass::ThreadFunctionToCalculateValue() {

    std::unique_lock<std::mutex> lock(m_mutex);

    m_calculated_value = ComplexLogicToCalculateValue();
    m_value_ready = true;

    m_my_condition_variable.notify_one();
}

Problem:
But the problem is that m_my_condition_variable.wait never returns.

Question:
What am I doing wrong here?

Is it a correct approach to make UI thread wait on a condition variable signal from worker thread? How do I get out of a situation where the condition_variable never triggers due to an error in the worker thread function? Is there a way I can somehow use a timeout here?