void BLASTBufferQueue::releaseBufferCallback(const ReleaseCallbackId& id,
                                             const sp<Fence>& releaseFence, uint32_t transformHint,
                                             uint32_t currentMaxAcquiredBufferCount) {
    std::unique_lock _lock{mMutex};
    releaseBufferCallbackLocked(id, releaseFence, transformHint, currentMaxAcquiredBufferCount);
}

申请锁，调用 BLASTBufferQueue::releaseBufferCallbackLocked()。