opencv/C++ problem

a server side on linux using opencv doing an image processing provided with two main functions the two functions do not depend on each other but they both do some processing on the same video so we want to run the two functions at the same time (like in parallel) not on a sequential order and provide the results as soon as it calculate it(do not wait for the other function to finish). note: we have the code for the functions and classes. also at the same time we want the server to keep listening for a connection and make connection with clients as long as the project is running.