In "C" (or C++, or whatever) this is trivial. When it comes back you iterate over what you got in said FDs to figure out which ones have flagged "ready" due to what reason and process whatever you've got. This is very efficient and works with any number of I/O channels open (well, up to the maximum your implementation can support at once.) Yes, I get it that if you might get a return on a blocking stream that is "false" (e.g. The arm-waving required to make this possible on Android looks both stupid and subject to significant risk of unannounced breakage if the underlying SSL library gets changed on you.