Fix race condition when trying to make several threads real-time simultaneously
Fix race condition when trying to make several threads real-time simultaneously

FluidSynth/fluidsynth,nezticle/fluidsynth,FluidSynth/fluidsynth,nezticle/fluidsynth,nezticle/fluidsynth,FluidSynth/fluidsynth,nezticle/fluidsynth,FluidSynth/fluidsynth