原文
This uses an old trick we used in SDL 1.2 for MacOS Classic, which did its audio callback in a hardware interrupt. If the audio is locked when the interrupt fires, make a note of it and return immediately. When the lock is released, if the interrupt has been fired, run the audio device iteration right then. Since there isn't a big device lock in SDL3 (available to the app, at least), this keeps a counter of when any SDL_AudioStream is locked, which is probably good enough.