I don't think we did have a correct answer, all of you. I may have a suggestion, but I am afraid of from Vietnam, you think me "advertise, be boastful". If you use "memory-mapped", you must synchronize (semaphore, mutex, spinlock, ...) but it makes your application slow. Then, "memory-mapped" is not a correct answer. Regards, Thuan PS: Something like: "Sorry, we are no longer accepting answers from your account because most of your answers need improvement or do not sufficiently answer the question. See the Help Center to learn more."