What can cause a conditional variable

Question

I implemented a simple ThreadPool that uses std::list<Tasks> mTasksfor a list of tasks.

All threads wait for the condition variable using the following code:

EnterCriticalSection(&mCriticalSection);

while(mTasks.size() ==0)
    SleepConditionVariableCS(&mConditionVariable,&mCriticalSection, INFINITE);

Until someone adds something to the list, and then one of them wakes up.

I used some time, which checks that the task list is not empty, although the only way to wake up is to add a new task to the list (so that it cannot be empty), the reason I did it is written on MSDN:

Variable conditions are subject to false awakenings (not associated with a clear trace) and stolen awakenings (another thread manages to run up to the swollen thread). Therefore, you should double-check the predicate (usually in a while loop) after the sleep operation returns.

But what are these side awakenings that will awaken my variable?

Answer 1

My understanding of this topic, while I was studying it at the university, was that it would be too expensive in terms of performance to implement 100% safe state variables.

The wikipedia page for false awakenings has a quote from David R. Butenhof (author Programming with POSIX Threads) that says:

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Answer 2

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