Algorithm set/info not threadsafe (Bug #2697)

without a sample code it's not possible to reproduce the problem. setting Algorithm properties should be thread-safe. info() method is not completely thread-safe, the first invocation may do some initialization, but the problem should not appear in the existing OpenCV classes.

so, please, provide the sample code so that we can reproduce the problem

Hello Vadim,

There is a new report with the same issue : http://code.opencv.org/issues/3292

I attached a sample code that reproduce the issue (tested on Linux with TBB).

Algorithm::info is implemented in the following way:

::cv::AlgorithmInfo* classname::info() const
{
    static volatile bool initialized = false;
    if( !initialized )
    {
        initialized = true;
        memberinit;
    }
    return &classname##_info();
}

There is no synchronization between threads.
So one thread can set initialized variable to true and go to sleep before memberinit, while the second thread will read initialized value as true and will use uninitialized struct.