Prevent FIFO threads from creating more FIFO threads.

            Process.setThreadGroup(tid, Binder.getCallingPid() == pid ?

                    Process.THREAD_GROUP_AUDIO_SYS : Process.THREAD_GROUP_AUDIO_APP);

            // must be in this order or it fails the schedulability constraint

            Process.setThreadScheduler(tid, Process.SCHED_FIFO, prio);

            Process.setThreadScheduler(tid, Process.SCHED_FIFO | Process.SCHED_RESET_ON_FORK,

                prio);

        } catch (RuntimeException e) {

            return PackageManager.PERMISSION_DENIED;

        }