search for: factorialfactory

...ds can >> read the same variable concurrently without locking provided none of the >> threads modifies the variable. > >That's true for simple types, but breaks down for classes because they >may have mutable members - e.g. for caching values computed lazily: > >class FactorialFactory { > private: > mutable int r = -1; > mutable int n; > public: > FactorialFactory() {} > > int calc(int v) const { > if (r < 0 || n != v) { > r = n; > n = v; > for (int i = n - 1; i > 1; --i) { > r *= i; >...

Hi, I have read the concurrency webpage from the Xapian documentation: http://getting-started-with-xapian.readthedocs.io/en/latest/concepts/concurrency.html But it is still not clear to me how to ensure thread-safety when using libxapian (C++ API). Usually when doing multi-threading many threads can read the same variable concurrently without locking provided none of the threads modifies the